MRI evaluaon of the normal and injured anterolateral ligament

Camilo Partezani Helito, MD

Hospital Sírio Libanês Knee Surgery Division, Department of Orthopedic Surgery, University of São Paulo, São Paulo, Brazil • No financial disclosures reported 4 Anatomy of the ALL, S. Claes et al.

the meniscus, the lateral inferior geniculate artery (LIGA) and vein were invariably found, situated in between the lateral meniscal rim and the ALL at the level of the joint line. More distally, the ALL inserted on the proximal tibia, thereby forming a thick capsular insertional fold. The tibial insertion of the ALL was always clearly situated posterior to Gerdy’s tubercle, with no connecting fibers to the ITB. Grossly, the tibial ALL insertion could be found in the mid- dle of the line connecting Gerdy’s tubercle and the tip of the fibular head. A graphic illustration of the ALL and its neighboring structures is provided in Figs 4 and 5.

Quantitative ALL characterization

The mean length of the ALL measured in neutral rotation and at 90º flexion was 41.5 6.7 and 38.5 6.1 mm in Æ Æ extension, illustrating some tensioning of the ligament dur-

ing mid-flexion. This increase in length during flexion was Fig. 5 Anatomic drawing of the axial view of a right knee at a level significant (P < 0.001). During manipulation of the knee above the meniscal surface. The intra-capsular course of the ALL is joint, we observed a maximal tension of the ALL during appreciated, as well as the triple layered anatomy of the lateral knee. combined flexion and internal rotation of the tibia. ALL, anterolateral ligament; ITB, iliotibial band; LCL, lateral collateral The mean width of the femoral origin measured ligament; GT, Gerdy’s tubercle; LIGA, lateral inferior geniculate artery; 8.3 2.1 mm. The ALL slightly narrowed near the level of PN, peroneal nerve; PCL, posterior cruciate ligament; ACL, anterior Æ cruciate ligament; LM, lateral meniscus; MM, medial meniscus; MCL, the joint line, with an average width of 6.7 3.0 mm. The Æ medial collateral ligament. ALL then broadened further distally, inserting on the proxi- mal tibia with a width of 11.2 2.5 mm. This distal flaring Æ of the ligament was clearly visible and highly significant (P < 0.0001; proximal vs. distal width). The thickness of the ALL at the level of the joint line, and after resection of the lateral meniscus, was 1.3 0.6 mm. Æ The insertion of the ALL on the tibia was quantified AB relative to bone landmarks of the proximal lower leg. The average distance between the proximal cartilage edge of the lateral tibia and the ALL insertion, i.e. the ‘lateral tibial recess’, was 6.5 1.4 mm. The center of • Æ A lot of recent interest the tibial ALL insertion was on average located 21.6 4.0 mm posterior to the center of Gerdy’s tubercle Æ The Orthopaedic Journal of Sports Medicine and 23.2 5.7 mm anteriorAnatomy to theof tip the of Anterolateral the fibular Ligament 3 Æ head. Individual ALL recordings of all dissected cases are summarized in Table 1. about the knee No correlation (P > 0.05) using a Student’s t-test was found between the individual ALL dimensions and knee size as measured by the distal femoral width at the level of Anterolateral Ligament the epicondyles and the intercondylar width. Discussion

The main finding of this study is that the anterolateral liga- ment (ALL) can be identified as a distinct ligamentous struc- ture at the anterolateral aspect of the human knee. • Although there have been sporadic reports (Campos et al. Several anatomical Fig. 4 Anatomic drawing considering the ALL and its relationship 2001; Haims et al. 2003; Vincent et al. 2012) mentioning the with well-known anatomical landmarks on the lateral aspect of the existence of a capsulo-ligamentous structure connecting the human knee. (A) Knee in full extension. (B) Knee in 90° of flexion. femur with the tibia at the (antero)lateral region of the ALL, anterolateral ligament; LCL, lateral collateral ligament; GT, Gerdy’s tubercle; LFE, lateral femoral epicondyle; PT, popliteus tendon; knee joint, information on the precise anatomy and func- studies published PFL, popliteo-fibular ligament. tion of this entity has always been vague and confusing. Figure 1. Anterolateral view of the right knee showing the Figure 3. Inside view of the lateral section of the right knee © 2013 Anatomical Society anterolateralClaes ligament et al, J anatomy (asterisk), the anterior cruciate ligament showing a triangular image with a distal base formed by the (dotted arrow), the posterior cruciate ligament (solid arrow), tibia, popliteus tendon (2), and the meniscal portion of the the fibular head (FH), the Gerdy tubercle (Gt), and the lateral anterolateral ligament (1). • Some MRI studies collateral ligament (LCL).

TABLE 2 Anatomic Locations of the Femoral, Tibial, and Meniscal about the normal ALL Attachments of the Anterolateral Ligamenta Anatomic Landmark Average SD Range

Femoral attachment Anterior to the LCL, mm 2.2 1.5 0-5 Distal to the LCL, mm 3.5 2.1 2-6 • Bifurcartion point from femoral Few studies focused attachment Distance, mm 20.3 4.1 14-26 Percentage of total ligament length 52.5 8.1 42-71 Meniscal attachment Anterior to the TPM, mm 19.4 3.5 13-22 on the ALL lesion using Tibial attachment Distal to the lateral plateau cartilage, mm 4.4 1.1 2-7 Between the fibular head and Gerdy 38 11 22-52 tubercle, Figure 2. Lateral view of the right knee showing 2 notable % ligament attachments, one more proximal in the lateral menis- aLCL, lateral collateral ligament; SD, standard deviation; TPM, MRI cus (dotted arrow), in the peripheral portion of the transition tendon of the popliteus muscle. between theHelito et al, OJSM anterior horn and the body, and the other more distal between the Gerdy tubercle and the fibular head (aster- isk). Lateral collateral ligament is indicated by the solid arrow. mean width, 7.4 + 1.7 mm (range, 5-11 mm); and mean thickness, 2.7 + 0.6 mm (range, 2-4 mm). base formed by the tibia, popliteus tendon, and the menis- In the histological analysis of the ligaments, the presence cal portion of the ALL (Figure 3). of dense connective tissue with arranged fibers and little The tibial attachment was found to be approximately cellular material was found in all specimens (Figure 4). 4.4 + 1.1 mm from the most distal portion of the anterior articular cartilage of the proximal tibia. Considering 2 imaginary lines, one tangent to the posterior border of the DISCUSSION Gerdy tubercle and the other tangent to the anterior border of the fibular head, the tibial attachment occurs at 38% + The aim of this study was to investigate the presence of a 11% of the way from the fibular head to the Gerdy tubercle ligament structure in the anterolateral region of the knee (Table 2). and determine the anatomic parameters of this ligament. The measurements found for the ligament were as This line of research can be very significant because the follows: mean length, 37.3 + 4.0 mm (range, 33-46 mm); current techniques of ACL reconstruction may not achieve

Downloaded from ojs.sagepub.com by guest on December 26, 2013

216 • Is it possible to idenfy ALL using MRI? r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

A B C

FEM

1 P 1 1

2 2

2 ML 3 3

TIB

3

Fig. 1 – (A) Schematic drawing; (B) coronal MRI slice; (C) anatomical photo of the ALL of the knee. In these three images,

arrow 1 (green) represents the femoral portion, arrow 2 (red) the meniscal portion and arrow 3 (blue) the tibial portion. P,

tendon of the popliteal muscle; FEM, lateral femoral condyle; TIB, lateral tibial plateau. (For interpretation of the references

to color in this figure legend, the reader is referred to the web version of the article.)

evaluations with a minimum interval of 30 days between

Table 1 – Number of views and percentage viewing of

them. In the event of lack of agreement in the evaluations, two

each portion of the ALL of the knee separately and of all

other evaluators viewed the MRI scans to determine whether of the portions together, in 33 MRI examinations.

the structure was present or not.

Number of views Percentage (%)

In evaluating the views of the ALL, we divided the analy-

5 Femoral portion 23 69.6%

sis into three portions of the ligament: (1) from the femoral

Meniscal portion 25 75.7%

origin to the point of bifurcation; (2) from the bifurcation to

Tibial portion 13 39.3%

the meniscal insertion; and (3) from the bifurcation to the tib-

Any portion of the ligament 27 81.8%

ial insertion (Fig. 1). For didactic purposes, these portions are

Entire ligament 11 33.3%

called the femoral, meniscal and tibial portions here.

The capacity to view the ligament in each of the portions

and in its entirety was considered to be a dichotomous cate- tract, with its insertion slightly posteriorly to Gerdy’s tubercle

gorical variable (yes or no). (Fig. 2).

The characterization of the ligament in the sequences

acquired in the axial and sagittal planes was limited. These

sequences were used for confirming the location of the ALL,

Results

based on parameters from anatomical studies (Fig. 3).

From analyzing the MRI examinations, it was seen that

The ALL was viewed on the knee MRI scans as a thin linear

some portion of the ligament could be clearly viewed in 27

structure, with an outline that sometimes was regular and

knees (81.8%). In these, the meniscal portion of the ligament

sometimes was undulating. It presented signal characteristics

was the one most frequently viewed, observed in 25 knees

similar to those of the other ligament structures of the knee,

(75.7%). The femoral portion was observed in 23 knees (69.6%)

with hyposignal seen on T2 images with fat saturation.

and the tibial portion in 13 (39.3%). The three portions together

The main plane in which the ligament was identified was

were viewed in 11 knees (33.3%) (Table 1).

the coronal plane. The femoral portion was identified as a

In four cases, there was disagreement between the evalua-

structure with its origin close to the anterior limit of the

tors regarding the presence of the ALL structure: two regarding

origin of the LCL, with an inferior path that was practically

the femoral portion and two regarding the meniscal portion.

vertical and superficial to the popliteal tendon, with bifurca-

In these cases, two auxiliary evaluators made complementary

tion less than 0.5 cm from the corpus of the lateral meniscus.

assessments and confirmed its presence.

The meniscal portion of the ligament presented an anteroin-

ferior oblique path from the bifurcation toward the anterior

corpus–cornu transition of the meniscus, viewed on subse- Discussion

quent coronal slices. The tibial portion was best characterized

immediately after the bifurcation, with a lateral and practi- The ALL of the knee has recently been better character-

1,3–5 2

cally vertical path. It maintained proximity to the iliotibial ized in anatomical studies. Although Vieira et al. named

216 r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

A B C

FEM

1 P 1 1

2 2

2 ML 3 3

TIB

3

Fig. 1 – (A) Schematic drawing; (B) coronal MRI slice; (C) anatomical photo of the ALL of the knee. In these three images,

arrow 1 (green) represents the femoral portion, arrow 2 (red) the meniscal portion and arrow 3 (blue) the tibial portion. P,

tendon of the popliteal muscle; FEM, lateral femoral condyle; TIB, lateral tibial plateau. (For interpretation of the references

to color in this figure legend, the reader is referred to the web version of the article.)

r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

evaluations with a minimum interval of 30 days between

Table 1 – Number of views and percentage viewing of

them. In the event of lack of agreement in the evaluations, two

each portion of the ALL of the knee separately and of all

www.rbo.org.br

other evaluators viewed the MRI scans to determine whether of the portions together, in 33 MRI examinations.

the structure was present or not.

Number of views Percentage (%)

Original article

In evaluating the views of the ALL, we divided the analy-

5 Femoral portion 23 69.6%

Evaluation ofsistheintoanterolateralthree portionsligamentof the ligament:of the knee(1) from the femoral

ଝ Meniscal portion 25 75.7%

by means oforiginmagneticto theresonancepoint of bifurcation;examination(2) from the bifurcation to

Tibial portion 13 39.3%

the meniscal insertion; and (3) from the bifurcation to the tib-

Camilo Partezani Helito ∗, Marco Kawamura Demange, Paulo Victor Partezani Helito, Any portion of the ligament 27 81.8%

ial insertion (Fig. 1). For didactic purposes, these portions are

Hugo Pereira Costa, Marcelo Batista Bonadio,r e v b rJosea s Ricardoo r t oPecora,p . 2 0 1 5;5 0(2):214–219 Entire ligament 21711 33.3%

Marcelo Bordalo Rodrigues,called theGilbertofemoral,Luis Camanhomeniscal and tibial portions here.

Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil

The capacity to view the ligament in each of the portions

and in its entirety was considered to be a dichotomous cate- tract, with its insertion slightly posteriorly to Gerdy’s tubercle

a r t i c l e i n f o a b s t r a c t

gorical variable (yes or no). (Fig. 2).

Article history: Objective: To evaluate the presence of the anterolateral ligament (ALL) of the knee in mag-

Received 17 January 2014 netic resonance imaging (MRI) examinations.

The characterization of the ligament in the sequences

Accepted 7 March 2014 Methods: Thirty-three MRI examinations on patients’ knees that were done because of indi-

Available online 7 April 2015 cations unrelated to ligament instability or trauma were evaluated. T1-weighted images in

acquired in the axial and sagittal planes was limited. These

the sagittal plane and T2-weighted images with fat saturation in the axial, sagittal and coro-

nal planes were obtained. The images were evaluated by two radiologists with experience

Keywords: sequences were used for confirming the location of the ALL,

Knee Results of musculoskeletal pathological conditions. In assessing ligament visibility, we divided the

Joint instability analysis into three portions of the ligament: from its origin in the femur to its point of bifur- based on parameters from anatomical studies (Fig. 3).

Magnetic resonance imaging cation; from the bifurcation to the meniscal insertion; and from the bifurcation to the tibial

Anatomy insertion. The capacity to view the ligament in each of its portions and overall was taken to From analyzing the MRI examinations, it was seen that

be a dichotomous categorical variable (yes or no).

The ALL was viewed on the knee MRI scans as a thin linear

Results: The ALL was viewed with signal characteristics similar to those of the other ligament some portion of the ligament could be clearly viewed in 27

structure,structures withof anthe knee,outlinewith T2 hyposignalthatwithsometimesfat saturation. The mainwasplaneregularin which and

the ligament was viewed was the coronal plane. Some portion of the ligament was viewed knees (81.8%). In these, the meniscal portion of the ligament

sometimesclearly wasin 27 kneesundulating.(81.8%). The meniscalItportionpresentedwas evident insignal25 knees (75.7%),characteristicsthe femoral

was the one most frequently viewed, observed in 25 knees

portion in 23 (69.6%) and the tibial portion in 13 (39.3%). The three portions were viewed

similar totogetherthose in 11ofkneesthe(33.3%).other ligament structures of the knee,

(75.7%). The femoral portion was observed in 23 knees (69.6%)

Conclusion: The anterolateral ligament of the knee is best viewed in sequences in the coro-

with hyposignalnal plane. Theseenligament wasoncompletelyT2 imagescharacterizedwithin 33.3%fatof thesaturation.cases. The meniscal

and the tibial portion in 13 (39.3%). The three portions together

portion was the part most easily identified and the tibial portion was the part least encoun-

The maintered. plane in which the ligament was identified was

were viewed in 11 knees (33.3%) (Table 1).

© 2014 Sociedade Brasileira de Ortopedia e Traumatologia. Published by Elsevier Editora

the coronal plane. The femoral portion wasLtda. Allidentifiedrights reserved. as a

In four cases, there was disagreement between the evalua-

structure with its origin close to the anterior limit of the

tors regarding the presence of the ALL structure: two regarding

origin of the LCL, with an inferior path that was practically

the femoral portion and two regarding the meniscal portion.

vertical and superficial to the popliteal tendon, with bifurca-

In these cases, two auxiliary evaluators made complementary

ଝ

Work developed in the Medical Investigation Laboratory for the Musculoskeletal System (LIM41), Department of Orthopedics and

tion less than 0.5 cm from the corpus of the lateral meniscus.

Traumatology, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil. assessments and confirmed its presence.

∗ Corresponding author.

Fig. 2 – T2-weighted coronalTheMRI meniscalslice withportionfat saturationof the ligamentshowing:presented(A) femoralan anteroin-portion; (B) meniscal portion; and (C) tibial

E-mail: camilo [email protected] (C.P. Helito).

http://dx.doi.org/10.1016/j.rboe.2015.03.009

portion of the ALL of the knee.

2255-4971/© 2014 SociedadeferiorBrasileira obliquede Ortopedia e Traumatologia.path fromPublishedtheby ElsevierbifurcationEditora Ltda. All rightstowardreserved. the anterior

corpus–cornu transition of the meniscus, viewed on subse- Discussion

quent coronal slices. The tibial portion was best characterized

immediately after the bifurcation, withthisa structure,lateral andtheypracti-did notThedescribeALL ofanythedetailedknee hasanatomi-recently been better character-

1,3–5 2

cally vertical path. It maintained proximitycal parametersto the iliotibialfor it. Its originized in anatomicalthe lateral condylestudies. andAlthoughits Vieira et al. named

two insertions have been clearly identified in the knees of

1,4,5

cadavers. Its bifurcation point and meniscal insertion were

3

most clearly demonstrated in the studies by Helito et al. and

5

Claes et al.

This structure may have importance in the genesis of

anterolateral instability of the knee. The importance of this

joint capsule region in rotational instability has been shown

in biomechanical studies, although these did not focus specif-

8

ically on the ALL.

Even though these studies suggested that injury to this

ligament would increase the anterolateral instability and con-

sequently the grade in the pivot-shift test (which is considered

to be the main predictor of functional results following ACL

reconstruction), there are still not many studies demonstrat-

ing the possibility of viewing this structure through the MRI

protocols generally used, i.e. in T2-weighted sequences with

fat saturation and T1-weighted sequencers, in the sagittal,

6,9

coronal and axial planes.

Our study showed that it was not possible to view the ALL

in all the knees when MRI was performed with the above-

mentioned sequences, especially with regard to viewing all

its portions.

We consider that it is important to completely character-

ize the ALL, i.e. its entire structure in a single examination, so

as to make an imaging evaluation of this structure in cases of

suspected injury. Furthermore, understanding the limitations

on viewing the entire ligament in MRI examinations makes it

possible to better determine the predictive value of this test

for identifying injuries. Failure to view the ligament can be

attributed to injury or simply the limitations of MRI evalua-

tions.

In our study, we were able to view all the portions of the

Fig. 3 – T2-weighted MRI slices with fat saturation: (A) structure in only 33.3% of the cases. At least one portion of

coronal slice showing ALL of the knee; (B) sagittal slice and the structure was viewed in 81.8% of the examinations. The

(C) axial slice showing the topographic location of the portion that was viewed most often was the meniscal portion

ligament based on anatomical parameters. (75.7%), while the tibial portion was viewed least often (39.3%).

216 r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

A B C

FEM

1 P 1 1

2 2

2 ML 3 3

TIB

3

Fig. 1 – (A) Schematic drawing; (B) coronal MRI slice; (C) anatomical photo of the ALL of the knee. In these three images,

arrow 1 (green) represents the femoral portion, arrow 2 (red) the meniscal portion and arrow 3 (blue) the tibial portion. P,

tendon of the popliteal muscle; FEM, lateral femoral condyle; TIB, lateral tibial plateau. (For interpretation of the references

to color in this figure legend, the reader is referred to the web version of the article.)

r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

evaluations with a minimum interval of 30 days between

Table 1 – Number of views and percentage viewing of

them. In the event of lack of agreement in the evaluations, two

each portion of the ALL of the knee separately and of all

www.rbo.org.br

other evaluators viewed the MRI scans to determine whether of the portions together, in 33 MRI examinations.

the structure was present or not.

Number of views Percentage (%)

Original article

In evaluating the views of the ALL, we divided the analy-

5 Femoral portion 23 69.6%

Evaluation ofsistheintoanterolateralthree portionsligamentof the ligament:of the knee(1) from the femoral

ଝ Meniscal portion 25 75.7%

by means oforiginmagneticto theresonancepoint of bifurcation;examination(2) from the bifurcation to

Tibial portion 13 39.3%

the meniscal insertion; and (3) from the bifurcation to the tib-

Camilo Partezani Helito ∗, Marco Kawamura Demange, Paulo Victor Partezani Helito, Any portion of the ligament 27 81.8%

ial insertion (Fig. 1). For didactic purposes, these portions are

Hugo Pereira Costa, Marcelo Batista Bonadio,r e v b rJosea s Ricardoo r t oPecora,p . 2 0 1 5;5 0(2):214–219 Entire ligament 21711 33.3%

Marcelo Bordalo Rodrigues,called theGilbertofemoral,Luis Camanhomeniscal and tibial portions here.

Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil

The capacity to view the ligament in each of the portions

and in its entirety was considered to be a dichotomous cate- tract, with its insertion slightly posteriorly to Gerdy’s tubercle

a r t i c l e i n f o a b s t r a c t

gorical variable (yes or no). (Fig. 2).

Article history: Objective: To evaluate the presence of the anterolateral ligament (ALL) of the knee in mag-

Received 17 January 2014 netic resonance imaging (MRI) examinations.

The characterization of the ligament in the sequences

Accepted 7 March 2014 Methods: Thirty-three MRI examinations on patients’ knees that were done because of indi-

Available online 7 April 2015 cations unrelated to ligament instability or trauma were evaluated. T1-weighted images in

acquired in the axial and sagittal planes was limited. These

the sagittal plane and T2-weighted images with fat saturation in the axial, sagittal and coro-

nal planes were obtained. The images were evaluated by two radiologists with experience

Keywords: sequences were used for confirming the location of the ALL,

Knee Results of musculoskeletal pathological conditions. In assessing ligament visibility, we divided the

Joint instability analysis into three portions of the ligament: from its origin in the femur to its point of bifur- based on parameters from anatomical studies (Fig. 3).

Magnetic resonance imaging cation; from the bifurcation to the meniscal insertion; and from the bifurcation to the tibial

Anatomy insertion. The capacity to view the ligament in each of its portions and overall was taken to From analyzing the MRI examinations, it was seen that

be a dichotomous categorical variable (yes or no).

The ALL was viewed on the knee MRI scans as a thin linear

Results: The ALL was viewed with signal characteristics similar to those of the other ligament some portion of the ligament could be clearly viewed in 27

structure,structures withof anthe knee,outlinewith T2 hyposignalthatwithsometimesfat saturation. The mainwasplaneregularin which and

the ligament was viewed was the coronal plane. Some portion of the ligament was viewed knees (81.8%). In these, the meniscal portion of the ligament

sometimesclearly wasin 27 kneesundulating.(81.8%). The meniscalItportionpresentedwas evident insignal25 knees (75.7%),characteristicsthe femoral

was the one most frequently viewed, observed in 25 knees

portion in 23 (69.6%) and the tibial portion in 13 (39.3%). The three portions were viewed

similar totogetherthose in 11ofkneesthe(33.3%).other ligament structures of the knee,

(75.7%). The femoral portion was observed in 23 knees (69.6%)

Conclusion: The anterolateral ligament of the knee is best viewed in sequences in the coro-

with hyposignalnal plane. Theseenligament wasoncompletelyT2 imagescharacterizedwithin 33.3%fatof thesaturation.cases. The meniscal

and the tibial portion in 13 (39.3%). The three portions together

portion was the part most easily identified and the tibial portion was the part least encoun-

The maintered. plane in which the ligament was identified was

were viewed in 11 knees (33.3%) (Table 1).

© 2014 Sociedade Brasileira de Ortopedia e Traumatologia. Published by Elsevier Editora

the coronal plane. The femoral portion wasLtda. Allidentifiedrights reserved. as a

In four cases, there was disagreement between the evalua-

structure with its origin close to the anterior limit of the

tors regarding the presence of the ALL structure: two regarding

origin of the LCL, with an inferior path that was practically

the femoral portion and two regarding the meniscal portion.

vertical and superficial to the popliteal tendon, with bifurca-

In these cases, two auxiliary evaluators made complementary

ଝ

Work developed in the Medical Investigation Laboratory for the Musculoskeletal System (LIM41), Department of Orthopedics and

tion less than 0.5 cm from the corpus of the lateral meniscus.

Traumatology, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil. assessments and confirmed its presence.

∗ Corresponding author.

Fig. 2 – T2-weighted coronalTheMRI meniscalslice withportionfat saturationof the ligamentshowing:presented(A) femoralan anteroin-portion; (B) meniscal portion; and (C) tibial

E-mail: camilo [email protected] (C.P. Helito).

http://dx.doi.org/10.1016/j.rboe.2015.03.009

portion of the ALL of the knee.

2255-4971/© 2014 SociedadeferiorBrasileira obliquede Ortopedia e Traumatologia.path fromPublishedtheby ElsevierbifurcationEditora Ltda. All rightstowardreserved. the anterior

corpus–cornu transition of the meniscus, viewed on subse- Discussion

quent coronal slices. The tibial portion was best characterized

immediately after the bifurcation, withthisa structure,lateral andtheypracti-did notThedescribeALL ofanythedetailedknee hasanatomi-recently been better character-

1,3–5 2

cally vertical path. It maintained proximitycal parametersto the iliotibialfor it. Its originized in anatomicalthe lateral condylestudies. andAlthoughits Vieira et al. named

two insertions have been clearly identified in the knees of

1,4,5

cadavers. Its bifurcation point and meniscal insertion were

3

most clearly demonstrated in the studies by Helito et al. and

5

Claes et al.

This structure may have importance in the genesis of

anterolateral instability of the knee. The importance of this

joint capsule region in rotational instability has been shown

in biomechanical studies, although these did not focus specif-

8

ically on the ALL.

Even though these studies suggested that injury to this

ligament would increase the anterolateral instability and con-

sequently the grade in the pivot-shift test (which is considered

to be the main predictor of functional results following ACL

reconstruction), there are still not many studies demonstrat-

ing the possibility of viewing this structure through the MRI

protocols generally used, i.e. in T2-weighted sequences with

fat saturation and T1-weighted sequencers, in the sagittal,

6,9

coronal and axial planes.

Our study showed that it was not possible to view the ALL

in all the knees when MRI was performed with the above-

mentioned sequences, especially with regard to viewing all

its portions.

We consider that it is important to completely character-

ize the ALL, i.e. its entire structure in a single examination, so

as to make an imaging evaluation of this structure in cases of

suspected injury. Furthermore, understanding the limitations

on viewing the entire ligament in MRI examinations makes it

possible to better determine the predictive value of this test

for identifying injuries. Failure to view the ligament can be

attributed to injury or simply the limitations of MRI evalua-

tions.

In our study, we were able to view all the portions of the

Fig. 3 – T2-weighted MRI slices with fat saturation: (A) structure in only 33.3% of the cases. At least one portion of

coronal slice showing ALL of the knee; (B) sagittal slice and the structure was viewed in 81.8% of the examinations. The

(C) axial slice showing the topographic location of the portion that was viewed most often was the meniscal portion

ligament based on anatomical parameters. (75.7%), while the tibial portion was viewed least often (39.3%).

216 r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

A B C

FEM

1 P 1 1

2 2

2 ML 3 3

TIB

3

Fig. 1 – (A) Schematic drawing; (B) coronal MRI slice; (C) anatomical photo of the ALL of the knee. In these three images,

arrow 1 (green) represents the femoral portion, arrow 2 (red) the meniscal portion and arrow 3 (blue) the tibial portion. P,

tendon of the popliteal muscle; FEM, lateral femoral condyle; TIB, lateral tibial plateau. (For interpretation of the references

to color in this figure legend, the reader is referred to the web version of the article.)

r e v b r a s o r t o p . 2 0 1 5;5 0(2):214–219

evaluations with a minimum interval of 30 days between

Table 1 – Number of views and percentage viewing of

them. In the event of lack of agreement in the evaluations, two

each portion of the ALL of the knee separately and of all

www.rbo.org.br

other evaluators viewed the MRI scans to determine whether of the portions together, in 33 MRI examinations.

the structure was present or not.

Number of views Percentage (%)

Original article

In evaluating the views of the ALL, we divided the analy-

5 Femoral portion 23 69.6%

Evaluation ofsistheintoanterolateralthree portionsligamentof the ligament:of the knee(1) from the femoral

ଝ Meniscal portion 25 75.7%

by means oforiginmagneticto theresonancepoint of bifurcation;examination(2) from the bifurcation to

Tibial portion 13 39.3%

the meniscal insertion; and (3) from the bifurcation to the tib-

Camilo Partezani Helito ∗, Marco Kawamura Demange, Paulo Victor Partezani Helito, Any portion of the ligament 27 81.8%

ial insertion (Fig. 1). For didactic purposes, these portions are

Hugo Pereira Costa, Marcelo Batista Bonadio,r e v b rJosea s Ricardoo r t oPecora,p . 2 0 1 5;5 0(2):214–219 Entire ligament 21711 33.3%

Marcelo Bordalo Rodrigues,called theGilbertofemoral,Luis Camanhomeniscal and tibial portions here.

Institute of Orthopedics and Traumatology, Hospital das Clínicas, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil

The capacity to view the ligament in each of the portions

and in its entirety was considered to be a dichotomous cate- tract, with its insertion slightly posteriorly to Gerdy’s tubercle

a r t i c l e i n f o a b s t r a c t

gorical variable (yes or no). (Fig. 2).

Article history: Objective: To evaluate the presence of the anterolateral ligament (ALL) of the knee in mag-

Received 17 January 2014 netic resonance imaging (MRI) examinations.

The characterization• ofNew structure” the ligament in the sequences

“

Accepted 7 March 2014 Methods: Thirty-three MRI examinations on patients’ knees that were done because of indi-

Available online 7 April 2015 cations unrelated to ligament instability or trauma were evaluated. T1-weighted images in

acquired in the axial and sagittal planes was limited. These

the sagittal plane and T2-weighted images with fat saturation in the axial, sagittal and coro-

nal planes were obtained. The images were evaluated by two radiologists with experience

Keywords: sequences were used• forLack of experience confirming the location of the ALL,

Knee Results of musculoskeletal pathological conditions. In assessing ligament visibility, we divided the

Joint instability analysis into three portions of the ligament: from its origin in the femur to its point of bifur- based on parameters from anatomical studies (Fig. 3).

Magnetic resonance imaging cation; from the bifurcation to the meniscal insertion; and from the bifurcation to the tibial

Anatomy insertion. The capacity to view the ligament in each of its portions and overall was taken to From analyzing the MRIfrom radiologists and examinations, it was seen that

be a dichotomous categorical variable (yes or no).

The ALL was viewed on the knee MRI scans as a thin linear

Results: The ALL was viewed with signal characteristics similar to those of the other ligament some portion of the ligament could be clearly viewed in 27

structure,structures withof anthe knee,outlinewith T2 hyposignalthatwithsometimesfat saturation. The mainwasplaneregularin which and

knees (81.8%). In these, theknee surgeons meniscal portion of the ligament

the ligament was viewed was the coronal plane. Some portion of the ligament was viewed

sometimesclearly wasin 27 kneesundulating.(81.8%). The meniscalItportionpresentedwas evident insignal25 knees (75.7%),characteristicsthe femoral

was the one most frequently viewed, observed in 25 knees

portion in 23 (69.6%) and the tibial portion in 13 (39.3%). The three portions were viewed

similar totogetherthose in 11ofkneesthe(33.3%).other ligament structures of the knee,

(75.7%). The femoral•portion No specific protocols was observed in 23 knees (69.6%)

Conclusion: The anterolateral ligament of the knee is best viewed in sequences in the coro-

with hyposignalnal plane. Theseenligament wasoncompletelyT2 imagescharacterizedwithin 33.3%fatof thesaturation.cases. The meniscal

and the tibial portion in 13 (39.3%). The three portions together

portion was the part most easily identified and the tibial portion was the part least encoun-

The maintered. plane in which the ligament was identified was

were viewed in 11 knees• No “clues” to find this (33.3%) (Table 1).

© 2014 Sociedade Brasileira de Ortopedia e Traumatologia. Published by Elsevier Editora

the coronal plane. The femoral portion wasLtda. Allidentifiedrights reserved. as a

In four cases, there was disagreement between the evalua-

structure with its origin close to the anterior limit of the

tors regarding the presencestructure of the ALL structure: two regarding

origin of the LCL, with an inferior path that was practically

the femoral portion and two regarding the meniscal portion.

vertical and superficial to the popliteal tendon, with bifurca-

In these cases, two auxiliary evaluators made complementary

ଝ

Work developed in the Medical Investigation Laboratory for the Musculoskeletal System (LIM41), Department of Orthopedics and

tion less than 0.5 cm from the corpus of the lateral meniscus.

Traumatology, School of Medicine, Universidade de São Paulo, São Paulo, SP, Brazil. assessments and confirmed its presence.

∗ Corresponding author.

Fig. 2 – T2-weighted coronalTheMRI meniscalslice withportionfat saturationof the ligamentshowing:presented(A) femoralan anteroin-portion; (B) meniscal portion; and (C) tibial

E-mail: camilo [email protected] (C.P. Helito).

http://dx.doi.org/10.1016/j.rboe.2015.03.009

portion of the ALL of the knee.

2255-4971/© 2014 SociedadeferiorBrasileira obliquede Ortopedia e Traumatologia.path fromPublishedtheby ElsevierbifurcationEditora Ltda. All rightstowardreserved. the anterior

corpus–cornu transition of the meniscus, viewed on subse- Discussion

quent coronal slices. The tibial portion was best characterized

immediately after the bifurcation, withthisa structure,lateral andtheypracti-did notThedescribeALL ofanythedetailedknee hasanatomi-recently been better character-

1,3–5 2

cally vertical path. It maintained proximitycal parametersto the iliotibialfor it. Its originized in anatomicalthe lateral condylestudies. andAlthoughits Vieira et al. named

two insertions have been clearly identified in the knees of

1,4,5

cadavers. Its bifurcation point and meniscal insertion were

3

most clearly demonstrated in the studies by Helito et al. and

5

Claes et al.

This structure may have importance in the genesis of

anterolateral instability of the knee. The importance of this

joint capsule region in rotational instability has been shown

in biomechanical studies, although these did not focus specif-

8

ically on the ALL.

Even though these studies suggested that injury to this

ligament would increase the anterolateral instability and con-

sequently the grade in the pivot-shift test (which is considered

to be the main predictor of functional results following ACL

reconstruction), there are still not many studies demonstrat-

ing the possibility of viewing this structure through the MRI

protocols generally used, i.e. in T2-weighted sequences with

fat saturation and T1-weighted sequencers, in the sagittal,

6,9

coronal and axial planes.

Our study showed that it was not possible to view the ALL

in all the knees when MRI was performed with the above-

mentioned sequences, especially with regard to viewing all

its portions.

We consider that it is important to completely character-

ize the ALL, i.e. its entire structure in a single examination, so

as to make an imaging evaluation of this structure in cases of

suspected injury. Furthermore, understanding the limitations

on viewing the entire ligament in MRI examinations makes it

possible to better determine the predictive value of this test

for identifying injuries. Failure to view the ligament can be

attributed to injury or simply the limitations of MRI evalua-

tions.

In our study, we were able to view all the portions of the

Fig. 3 – T2-weighted MRI slices with fat saturation: (A) structure in only 33.3% of the cases. At least one portion of

coronal slice showing ALL of the knee; (B) sagittal slice and the structure was viewed in 81.8% of the examinations. The

(C) axial slice showing the topographic location of the portion that was viewed most often was the meniscal portion

ligament based on anatomical parameters. (75.7%), while the tibial portion was viewed least often (39.3%). Skeletal Radiol (2014) 43:1421–1427 1423

Fig. 1 Schematic drawing (a), MRI using a PD-weighted coronal acqui- iliotibial band; LCL lateral colateral ligament; P popliteus tendon; ILGA sition (b), and an anatomical photograph (c) showing the ALL, its origin inferior lateral genicular artery; ALL FEM anterolateral ligament femoral and insertion, and its relationship to adjacent structures. LFC lateral portion; ALL MEN anterolateral ligament meniscal portion; ALL TIB femoral condyle; LTP lateral tibial plafond; M lateral meniscus; ITB anterolateral ligament tibial portion 1426 Skeletal Radiol (2014) 43:1421–1427 commonly visualized (94.8 %), followed by the femoral observed above the lateral inferior geniculate artery, lying 3.0 Fig. 4 T1- (a), T2- (b), and PD- (89.7weighted %) and (c) tibial MRI scans(79.4 on %) the portions. The entire paths of all ±1.2 mm from the plane on the top edge of the lateral menis- threecoronal ligament plane. portions Note that were the ALL visualized in only 28 (71.7 %) cus body. scansis identified (Table 2). only with the PD From the bifurcation point, the ligament is divided into two Theweighting ALL in was this case characterized (arrow) with greater clarity on the sections based on their insertions: the meniscal and tibial. The coronal plane as a thin and linear structure with a thickness meniscal portion has an insertion in the anterior third of the varying between 1–3 mm and surrounded by adipose tissue or lateral meniscus body, and it is occasionally featured in more synovial fluid. In certain cases on the axial plane, a small oval than one consecutive section (Fig. 3). structure could be observed on the lateral side of the knee The tibial segment of the ALL has a more vertical path than between the iliotibial band and the LCL that corresponded to the meniscal segment and is inserted 7.0±1.0 mm beneath the the anatomical topography of the ALL. However, axial and plane of the lateral tibial plateau and subsequent to the inser- sagittal sequences were more useful for locating the anatom- tion of the iliotibial tract. The proximity to the iliotibial tract is ical parameters used as a reference to identify the ligament on a limiting factor in the individualization of this segment due to the coronal plane (Fig. 2). partial volume effects. The origin of the ALL on the outer face of the lateral According to the data analysis, the inter-rater agreement femoral condyle was located immediately anterior to the obtained by the kappa test ranged from 0.843 to 1.000 LCL, and it was difficult to accurately determine the origin (Table 3). point of the former because of the partial volume effects The T1 sequences showed a ligament visibility frequency associated with the latter. that was statistically inferior to the T2 and PD sequences for The ALL has an anteroinferior path, superficial to the all evaluated portions. With regard to the evaluation of T2 and Skeletal Radiol (2014) 43:1421–1427 originthe and ligament the popliteal are helpful tendon for groove. evaluators Its bifurcation who are less can experi- be PD, althoughThe characterization the visualization of frequency this structure in PD can was be higher important for for DOI 10.1007/s00256-014-1966-7 enced with this type of structure (Fig. 5). The identification ofthe threefuture portions studies because of the ligament, it might be only responsible the femoral for portion the propor- SCIENTIFIC ARTICLE the ALL bifurcation was one of the key parameters for iden- hadtion statistically of patients significant who do values not progress (Table 4 satisfactorily). after ACL Tabletifying 2 Absolute the ligament, numbers and and the its percentage clear demarcation of visualizations is an of important each reconstruction [16–18]. Although to date the failure of recon- portionsubjective of the ALL factor across for the increasing T1-, T2-, and diagnostic PD-weighted confidence. MRI sequences structions with appropriate tunnel positioning and graft size is MRI evaluation of the anterolateral ligament of the knee: PortionDue to the T1 very high interrater T2 agreement PD (greater than Discussionattributed to factors related to graft incorporation, we believe assessment in routine 1.5-T scans 80 %) obtained according to the kappa test [15], we believe that at least some of these failures may be associated with an that the MRIn evaluation% of thisn structure% is feasiblen and% should Recentinsufficient anatomical ALL. studies The have incidence successfully of anterior characterized cruciate ligament the be included among the evaluation protocols for suspected lesions combined with anterolateral ligament lesions has not Camilo Partezani Helito & Paulo Victor Partezani Helito & Hugo Pereira Costa & Femoral 11 28.2 27 69.2 35 89.7 ALL [1, 3–5]. Its origin in the lateral condyle and its two knee ligament injuries, especially in the presence of concom- been established in the literature so far. Marcelo Bordalo-Rodrigues & José Ricardo Pecora & Gilberto Luis Camanho & Meniscal 16 41.0 31 79.4 37 94.8 insertions were clearly identified in cadaver knees [5]. Helito Marco Kawamura Demange itant anterior cruciate ligament lesions. Because the evaluation During the initial evaluation of the MRIs we excluded three Tibial 11 28.2 25 64.1 31 79.4 et al. [3, 5] clearly demonstrated its bifurcation point and its of this ligament using MRI is at an inchoate stage, it is meniscalpatients insertion. because Slight of unexpected variations ACL in the injuries. femoral This attachment was not the All portions 8 20.5 18 46.1 28 71.7 possible that these minimal evaluation disagreements will weremain found focus by Vincentof this article, et al. [but1] in we relation tried to to assess the other the ALL three in all Any portion 18 46.1 34 87.1 38 97.4 Received: 19 March 2014 /Revised: 15 July 2014 /Accepted: 21 July 2014 /Published online: 3 August 2014 not occur in future studies as the examiners gain experience. anatomicalcases. Instudies. all of Vincent the examinations, et al. found the we ALL could insertion not clearly to Skeletal Radiol# ISS (2014) 2014 43:1421–1427 1423 delimitate any portion of the ALL, which could suggest that charicterization of the ALL is worse when combined with an Abstract Conclusion The ALL can be visualized in routine 1.5-T MRI Objective This study evaluated the ability of routine 1.5-T scans. Although some of the ligament could be depicted in ACL injury, but this conclusion needs further studies. MRI scans to visualize the anterolateral ligament (ALL) and nearly all of the scans (97.4 %), it could only be observed in its A possible limitation of this study is that the MRIs were describe its path and anatomic relations with lateral knee entirety in about 71.7 % of the tests. performed on patients without acute trauma to the knee who structures. therefore had a small amount of joint fluid. A larger quantity Materials and methods Thirty-nine 1.5-T MRI scans of the Keywords Knee . MRI . Anterolateral ligament . PD weight knee were evaluated. The scans included an MRI knee proto- sequence . Anatomy of liquid inside the joint may increase the tension in the knee col with T1-weighted sequences, T2-weighted sequences with capsule and facilitate the visualization of the ALL. For future fat saturation, and proton density (PD)-weighted fast spin- work, we suggest studying resonance knee examinations echo sequences. Two radiologists separately reviewed all Introduction among patients after acute knee trauma. Another limitation MRI scans to evaluate interobserver reliability. The ALL was divided into three portions for analyses: femoral, Segond [1] first mentioned the anterolateral ligament (ALL) in is the 1.5-T MRI, which might not be sufficient to clearly meniscal, and tibial. The path of the ALL was evaluated with the orthopedic literature in 1879. Despite having been de- evaluate the structure of the ALL and differentiate it from regard to known structural parameters previously studied in scribed for over 120 years, this structure was only recently Fig. 1 Schematic drawing (a), MRI using a PD-weighted coronal acqui- iliotibial band; LCL lateral colateral ligament; P popliteus tendon; ILGA adjacent structures; however, because this appliance is the sition (b), andthis an region. anatomical photograph (c) showing the ALL, its origin inferior lateral genicularnamed by artery; VieiraALL etFEM al.anterolateral [2] in a study ligament of the femoral iliotibial tract that most commonly used in clinical routines in our area, we and insertion,Results and itsAt relationship least a portion to adjacent of thestructures. ALLLFC waslateral visualizedportion; in 38ALL MENdid notanterolateral establish ligament any ALL meniscal parameter portion; ALL with TIB precision. Since femoral condyle;(97.8LTP %) cases.lateral tibial The plafond; meniscalM lateral portion meniscus; was mostITB visualizedanterolateral ligament2012, tibial anatomical portion studies have been conducted to define the considered it appropriate for use in this study. Furthermore, (94.8 %), followed by the femoral (89.7 %) and the tibial origin and insertion parameters, their path, and other specifics. the evaluators lacked experience in identifying this ligament, commonly(79.4 visualized %) portions. (94.8 The %), three followed portions by the of the femoral ALL wereobserved visu- aboveThus the far, lateral we inferior know ofgeniculate four anatomical artery, lying studies 3.0 that have fo- although they had attended several dissections to better char- (89.7 %)alized and tibial in 28(79.4 (71.7 %) portions. %) patients. The entireThe ALL paths was of all characterized±1.2 mm fromcused the plane specifically on the topon the edge ALL of the [1, lateral3–5]. menis- acterize the structure. three ligamentwith greater portions clarity wereon visualized the coronal in only plane 28 and (71.7 was %) visualizedcus body. as Fig. 5 PD-weighted MRI image of the coronal section showing the The origin of the ALL is in the lateral femoral condyle, Due to the percentage of intermediate visualization found scans (Tablea thin,2). linear structure. The T1-weighted sequences showedFrom a the bifurcationanterior and point, distal the to ligament the origin is divided of the into lateral two collateral liga- inferior lateral geniculate artery (arrowhead) below the ALL bifurcation The ALLstatistically was characterized inferior ligament with greater visibility clarity frequency. on the Withsections regard basedment on their (LCL) insertions: and between the meniscal the LCL and and tibial. the The popliteal tendon. (arrow) for the three portions of the ALL across the three acquisition coronal planeto the as T2 a thin and and PD linear evaluations, structure with although a thickness the visualizationmeniscal portionThe ALLhas an has insertion an oblique in the path anterior anteriorly third of and the inferiorly to the varying betweenfrequency 1–3 inmm PD and was surrounded higher by for adipose the three tissue portions or lateral of the meniscustibia, body, inserting and it on is occasionally the lateral meniscus featured and in more on the lateral tibial synovial fluid.ligament, In certain only cases the femoral on the axial portion plane, showed a small significant oval than values. one consecutivecondyle, section 6.5 mm (Fig. below3). the lateral tibial condyle chondral structure could be observed on the lateral side of the knee The tibialsurface segment [ of5]. the ALL has a more vertical path than between the iliotibial band and the LCL that corresponded to the meniscal segmentRecently, and isthis inserted structure 7.0±1.0 has become mm beneath increasingly the important; the anatomical topography of the ALL. However, axial and plane of the lateral tibial plateau and subsequent to the inser- Monaco et al. [6] suggested that it is associated with lesions of sagittal sequences were more: useful for: locating the: anatom- tion of the iliotibial tract. The proximity to the iliotibial tract is C. P. Helito (*) J. R. Pecora G. L. Camanho M. K. Demange the anterior cruciate ligament and the genesis of anterolateral ical parametersFaculty used of Medicine, as a reference Institute to of identify Orthopedics the ligament and Traumatology, on a limiting factor in the individualization of this segment due to knee instability. Thus, it has become important to conduct the coronalKnee plane Surgery (Fig. Division,2). University of São Paulo, São Paulo, Brazilpartial volume effects. The origine-mail: of [email protected] the ALL on the outer face of the lateral Accordingstudies to the identifying data analysis, the the ALL inter-rater using imaging. agreement femoral condyle was: located immediately: anterior to the obtained by theFew kappa authors test ranged have cited from radiological 0.843 to 1.000 visualization pa- P. V. P. Helito H. P. Costa M. Bordalo-Rodrigues rameters specific to this structure using MRI scans [7–9]. LCL, andFaculty it was of difficult Medicine, to Institute accurately of Orthopedics determine and the Traumatology, origin (Table 3). point ofMusculoskeletal the former because Radiology of the Department, partial volumeUniversity effects of São Paulo, The T1 sequencesFurthermore, showed recent a ligament studies visibility have suggested frequency that the com- associatedSão with Paulo, the Brazillatter. that was statisticallyplete identification inferior to the of T2 the and stru PDcture sequences is not for always possible. The ALL has an anteroinferior path, superficial to the all evaluated portions. With regard to the evaluation of T2 and origin and the popliteal tendon groove. Its bifurcation can be PD, although the visualization frequency in PD was higher for the three portions of the ligament, only the femoral portion had statistically significant values (Table 4). Table 2 Absolute numbers and the percentage of visualizations of each portion of the ALL across the T1-, T2-, and PD-weighted MRI sequences

Portion T1 T2 PD Discussion

n % n % n % Recent anatomical studies have successfully characterized the Femoral 11 28.2 27 69.2 35 89.7 ALL [1, 3–5]. Its origin in the lateral condyle and its two Meniscal 16 41.0 31 79.4 37 94.8 insertions were clearly identified in cadaver knees [5]. Helito Tibial 11 28.2 25 64.1 31 79.4 et al. [3, 5] clearly demonstrated its bifurcation point and its meniscal insertion. Slight variations in the femoral attachment All portions 8 20.5 18 46.1 28 71.7 were found by Vincent et al. [1] in relation to the other three Any portion 18 46.1 34 87.1 38 97.4 anatomical studies. Vincent et al. found the ALL insertion to Skeletal Radiol (2014) 43:1421–1427 1423

Fig. 1 Schematic drawing (a), MRI using a PD-weighted coronal acqui- iliotibial band; LCL lateral colateral ligament; P popliteus tendon; ILGA sition (b), and an anatomical photograph (c) showing the ALL, its origin inferior lateral genicular artery; ALL FEM anterolateral ligament femoral and insertion, and its relationship to adjacent structures. LFC lateral portion; ALL MEN anterolateral ligament meniscal portion; ALL TIB femoral condyle; LTP lateral tibial plafond; M lateral meniscus; ITB anterolateral ligament tibial portion 1426 Skeletal Radiol (2014) 43:1421–1427 commonly visualized (94.8 %), followed by the femoral observed above the lateral inferior geniculate artery, lying 3.0 Fig. 4 T1- (a), T2- (b), and PD- (89.7weighted %) and (c) tibial MRI scans(79.4 on %) the portions. The entire paths of all ±1.2 mm from the plane on the top edge of the lateral menis- threecoronal ligament plane. portions Note that were the ALL visualized in only 28 (71.7 %) cus body. scansis identified (Table 2). only with the PD From the bifurcation point, the ligament is divided into two Theweighting ALL in was this case characterized (arrow) with greater clarity on the sections based on their insertions: the meniscal and tibial. The coronal plane as a thin and linear structure with a thickness meniscal portion has an insertion in the anterior third of the varying between 1–3 mm and surrounded by adipose tissue or lateral meniscus body, and it is occasionally featured in more synovial fluid. In certain cases on the axial plane, a small oval than one consecutive section (Fig. 3). structure could be observed on the lateral side of the knee The tibial segment of the ALL has a more vertical path than between the iliotibial band and the LCL that corresponded to the meniscal segment and is inserted 7.0±1.0 mm beneath the the anatomical topography of the ALL. However, axial and plane of the lateral tibial plateau and subsequent to the inser- sagittal sequences were more useful for locating the anatom- tion of the iliotibial tract. The proximity to the iliotibial tract is ical parameters used as a reference to identify the ligament on a limiting factor in the individualization of this segment due to the coronal plane (Fig. 2). partial volume effects. The origin of the ALL on the outer face of the lateral According to the data analysis, the inter-rater agreement femoral condyle was located immediately anterior to the obtained by the kappa test ranged from 0.843 to 1.000 LCL, and it was difficult to accurately determine the origin (Table 3). point of the former because of the partial volume effects The T1 sequences showed a ligament visibility frequency associated with the latter. that was statistically inferior to the T2 and PD sequences for The ALL has an anteroinferior path, superficial to the all evaluated portions. With regard to the evaluation of T2 and Skeletal Radiol (2014) 43:1421–1427 originthe and ligament the popliteal are helpful tendon for groove. evaluators Its bifurcation who are less can experi- be PD, althoughThe characterization the visualization of frequency this structure in PD can was be higher important for for DOI 10.1007/s00256-014-1966-7 enced with this type of structure (Fig. 5). The identification ofthe threefuture portions studies because of the ligament, it might be only responsible the femoral for portion the propor- SCIENTIFIC ARTICLE the ALL bifurcation was one of the key parameters for iden- hadtion statistically of patients significant who do values not progress (Table 4 satisfactorily). after ACL Tabletifying 2 Absolute the ligament, numbers and and the its percentage clear demarcation of visualizations is an of important each reconstruction [16–18]. Although to date the failure of recon- portionsubjective of the ALL factor across for the increasing T1-, T2-, and diagnostic PD-weighted confidence. MRI sequences structions with appropriate tunnel positioning and graft size is MRI evaluation of the anterolateral ligament of the knee: PortionDue to the T1 very high interrater T2 agreement PD (greater than Discussionattributed to factors related to graft incorporation, we believe assessment in routine 1.5-T scans 80 %) obtained according to the kappa test [15], we believe that at least some of these failures may be associated with an that the MRIn evaluation% of thisn structure% is feasiblen and% should Recentinsufficient anatomical ALL. studies The have incidence successfully of anterior characterized cruciate ligament the be included among the evaluation protocols for suspected lesions combined with anterolateral ligament lesions has not Camilo Partezani Helito & Paulo Victor Partezani Helito & Hugo Pereira Costa & Femoral 11 28.2 27 69.2 35 89.7 ALL [1, 3–5]. Its origin in the lateral condyle and its two knee ligament injuries, especially in the presence of concom- been established in the literature so far. Marcelo Bordalo-Rodrigues & José Ricardo Pecora & Gilberto Luis Camanho & Meniscal 16 41.0 31 79.4 37 94.8 insertions were clearly identified in cadaver knees [5]. Helito Marco Kawamura Demange itant anterior cruciate ligament lesions. Because the evaluation During the initial evaluation of the MRIs we excluded three Tibial 11 28.2 25 64.1 31 79.4 et al. [3, 5] clearly demonstrated its bifurcation point and its of this ligament using MRI is at an inchoate stage, it is meniscalpatients insertion. because Slight of unexpected variations ACL in the injuries. femoral This attachment was not the All portions 8 20.5 18 46.1 28 71.7 possible that these minimal evaluation disagreements will weremain found focus by Vincentof this article, et al. [but1] in we relation tried to to assess the other the ALL three in all Any portion 18 46.1 34 87.1 38 97.4 Received: 19 March 2014 /Revised: 15 July 2014 /Accepted: 21 July 2014 /Published online: 3 August 2014 not occur in future studies as the examiners gain experience. anatomicalcases. Instudies. all of Vincent the examinations, et al. found the we ALL could insertion not clearly to Skeletal Radiol# ISS (2014) 2014 43:1421–1427 1423 delimitate any portion of the ALL, which could suggest that charicterization of the ALL is worse when combined with an Abstract Conclusion The ALL can be visualized in routine 1.5-T MRI Objective This study evaluated the ability of routine 1.5-T scans. Although some of the ligament could be depicted in Lateral ACL injury, but this conclusion needs further studies. MRI scans to visualize the anterolateral ligament (ALL) and nearly all of the scans (97.4 %), it could only be observed in its A possible limitation of this study is that the MRIs were describe its path and anatomic relations with lateral knee entirety in about 71.7 % of the tests. Inferior performed on patients without acute trauma to the knee who structures. therefore had a small amount of joint fluid. A larger quantity Materials and methods Thirty-nine 1.5-T MRI scans of the Keywords Knee . MRI . Anterolateral ligament . PD weight knee were evaluated. The scans included an MRI knee proto- sequence . Anatomy genicular of liquid inside the joint may increase the tension in the knee col with T1-weighted sequences, T2-weighted sequences with capsule and facilitate the visualization of the ALL. For future fat saturation, and proton density (PD)-weighted fast spin- vessels work, we suggest studying resonance knee examinations echo sequences. Two radiologists separately reviewed all Introduction among patients after acute knee trauma. Another limitation MRI scans to evaluate interobserver reliability. The ALL was divided into three portions for analyses: femoral, Segond [1] first mentioned the anterolateral ligament (ALL) in is the 1.5-T MRI, which might not be sufficient to clearly meniscal, and tibial. The path of the ALL was evaluated with the orthopedic literature in 1879. Despite having been de- evaluate the structure of the ALL and differentiate it from regard to known structural parameters previously studied in scribed for over 120 years, this structure was only recently Fig. 1 Schematic drawing (a), MRI using a PD-weighted coronal acqui- iliotibial band; LCL lateral colateral ligament; P popliteus tendon; ILGA adjacent structures; however, because this appliance is the sition (b), andthis an region. anatomical photograph (c) showing the ALL, its origin inferior lateral genicularnamed by artery; VieiraALL etFEM al.anterolateral [2] in a study ligament of the femoral iliotibial tract that most commonly used in clinical routines in our area, we and insertion,Results and itsAt relationship least a portion to adjacent of thestructures. ALLLFC waslateral visualizedportion; in 38ALL MENdid notanterolateral establish ligament any ALL meniscal parameter portion; ALL with TIB precision. Since femoral condyle;(97.8LTP %) cases.lateral tibial The plafond; meniscalM lateral portion meniscus; was mostITB visualizedanterolateral ligament2012, tibial anatomical portion studies have been conducted to define the considered it appropriate for use in this study. Furthermore, (94.8 %), followed by the femoral (89.7 %) and the tibial origin and insertion parameters, their path, and other specifics. the evaluators lacked experience in identifying this ligament, commonly(79.4 visualized %) portions. (94.8 The %), three followed portions by the of the femoral ALL wereobserved visu- aboveThus the far, lateral we inferior know ofgeniculate four anatomical artery, lying studies 3.0 that have fo- although they had attended several dissections to better char- (89.7 %)alized and tibial in 28(79.4 (71.7 %) portions. %) patients. The entireThe ALL paths was of all characterized±1.2 mm fromcused the plane specifically on the topon the edge ALL of the [1, lateral3–5]. menis- acterize the structure. three ligamentwith greater portions clarity wereon visualized the coronal in only plane 28 and (71.7 was %) visualizedcus body. as Fig. 5 PD-weighted MRI image of the coronal section showing the The origin of the ALL is in the lateral femoral condyle, Due to the percentage of intermediate visualization found scans (Tablea thin,2). linear structure. The T1-weighted sequences showedFrom a the bifurcationanterior and point, distal the to ligament the origin is divided of the into lateral two collateral liga- inferior lateral geniculate artery (arrowhead) below the ALL bifurcation The ALLstatistically was characterized inferior ligament with greater visibility clarity frequency. on the Withsections regard basedment on their (LCL) insertions: and between the meniscal the LCL and and tibial. the The popliteal tendon. (arrow) for the three portions of the ALL across the three acquisition coronal planeto the as T2 a thin and and PD linear evaluations, structure with although a thickness the visualizationmeniscal portionThe ALLhas an has insertion an oblique in the path anterior anteriorly third of and the inferiorly to the varying betweenfrequency 1–3 inmm PD and was surrounded higher by for adipose the three tissue portions or lateral of the meniscustibia, body, inserting and it on is occasionally the lateral meniscus featured and in more on the lateral tibial synovial fluid.ligament, In certain only cases the femoral on the axial portion plane, showed a small significant oval than values. one consecutivecondyle, section 6.5 mm (Fig. below3). the lateral tibial condyle chondral structure could be observed on the lateral side of the knee The tibialsurface segment [ of5]. the ALL has a more vertical path than between the iliotibial band and the LCL that corresponded to the meniscal segmentRecently, and isthis inserted structure 7.0±1.0 has become mm beneath increasingly the important; the anatomical topography of the ALL. However, axial and plane of the lateral tibial plateau and subsequent to the inser- Monaco et al. [6] suggested that it is associated with lesions of sagittal sequences were more: useful for: locating the: anatom- tion of the iliotibial tract. The proximity to the iliotibial tract is C. P. Helito (*) J. R. Pecora G. L. Camanho M. K. Demange the anterior cruciate ligament and the genesis of anterolateral ical parametersFaculty used of Medicine, as a reference Institute to of identify Orthopedics the ligament and Traumatology, on a limiting factor in the individualization of this segment due to knee instability. Thus, it has become important to conduct the coronalKnee plane Surgery (Fig. Division,2). University of São Paulo, São Paulo, Brazilpartial volume effects. The origine-mail: of [email protected] the ALL on the outer face of the lateral Accordingstudies to the identifying data analysis, the the ALL inter-rater using imaging. agreement femoral condyle was: located immediately: anterior to the obtained by theFew kappa authors test ranged have cited from radiological 0.843 to 1.000 visualization pa- P. V. P. Helito H. P. Costa M. Bordalo-Rodrigues rameters specific to this structure using MRI scans [7–9]. LCL, andFaculty it was of difficult Medicine, to Institute accurately of Orthopedics determine and the Traumatology, origin (Table 3). point ofMusculoskeletal the former because Radiology of the Department, partial volumeUniversity effects of São Paulo, The T1 sequencesFurthermore, showed recent a ligament studies visibility have suggested frequency that the com- associatedSão with Paulo, the Brazillatter. that was statisticallyplete identification inferior to the of T2 the and stru PDcture sequences is not for always possible. The ALL has an anteroinferior path, superficial to the all evaluated portions. With regard to the evaluation of T2 and origin and the popliteal tendon groove. Its bifurcation can be PD, although the visualization frequency in PD was higher for the three portions of the ligament, only the femoral portion had statistically significant values (Table 4). Table 2 Absolute numbers and the percentage of visualizations of each portion of the ALL across the T1-, T2-, and PD-weighted MRI sequences

Portion T1 T2 PD Discussion

n % n % n % Recent anatomical studies have successfully characterized the Femoral 11 28.2 27 69.2 35 89.7 ALL [1, 3–5]. Its origin in the lateral condyle and its two Meniscal 16 41.0 31 79.4 37 94.8 insertions were clearly identified in cadaver knees [5]. Helito Tibial 11 28.2 25 64.1 31 79.4 et al. [3, 5] clearly demonstrated its bifurcation point and its meniscal insertion. Slight variations in the femoral attachment All portions 8 20.5 18 46.1 28 71.7 were found by Vincent et al. [1] in relation to the other three Any portion 18 46.1 34 87.1 38 97.4 anatomical studies. Vincent et al. found the ALL insertion to Helito Helito Taneja Porrino Kosy Coquart Macchi

United Country Brazil Brazil Brazil USA France Italy Kingdon

Characterized

(enre or 97.8% 81.8% 51% 100% 94% 93.5% 93%

part)

Not idenfied 2.2% 18.2% 49% 0% 6% 6.5% 7% 1424 Skeletal Radiol (2014) 43:1421–1427

Fig. 2 MRI of the coronal plane with PD-weighting (a) clearly showing the ALL (asterisk). Sagittal T1-weighted image (b) and axial T2-weighted fat-saturated image (c) with guidelines showing the location of the coronal plane upon which the ligament can be visualized. Note that it is possible to identify the ALL on the axial plane as a thin structure with low signal (white arrow head) anterior to the lateral collateral ligament (white arrow)

Skeletal Radiol (2014) 43:1421–1427 DOI 10.1007/s00256-014-1966-7 be close to the popliteus tendon while the other studies found Since its initial description by Segond [1], certain knee it to be in close relation to the lateral collateral ligament origin. MRI studies have referred to the ability to visualize a ligament SCIENTIFIC ARTICLE This structure might be important in the genesis of antero- structure in the lateral region of the knee [11–13], sometimes lateral knee instability. The authors of a biomechanical study referred as the lateral capsular ligament, and have related this have shown the importance of this articular capsule region structure to the genesis of Segond fracture. However, none of MRI evaluation of the anterolateralwith ligament regard to rotational of the instability, knee: although they did not these studies have evaluated the MRI’s ability to visualize the specifically address the ALL [6]. ALL in living people, nor have they described its imaging assessment in routine 1.5-T scans The above study suggests that injury to this ligament in- appearance or its relationship to adjacent structures in detail. creases anterolateral instability and consequently pivot-shift This is most likely due to the lack of clinical importance given Camilo Partezani Helito & Paulo Victor Partezani Helito & Hugotest Pereira grading, Costa which& is the primary predictor of functional to the ALL until recently. Marcelo Bordalo-Rodrigues & José Ricardo Pecora & Gilbertooutcomes Luis Camanho after ACL& ligament reconstruction. However, only Our study showed that it was not possible to visualize Marco Kawamura Demange a few studies have indicated the possibility of visualizing this the ALL in all knees using routine 1.5-T MRI protocols, 1424 Skeletal Radiol (2014) 43:1421–1427 structure using the most commonly performed MRI protocols especially with regard to visualizing all portions of this [7, 10]. structure. Fig. 2 MRI of the coronal plane with PD-weighting (a) clearly Received: 19 March 2014 /Revised: 15 July 2014 /Accepted: 21 July 2014 /Published online: 3 August 2014 showing the ALL (asterisk). # ISS 2014 Fig. 3 Two subsequent PD- Sagittal T1-weighted image Abstract weightedConclusion MRI scansThe ALL on the can be visualized in routine 1.5-T MRI (b) and axial T2-weighted coronal plane showing the ALL. Objective This study evaluated the ability of routine 1.5-T scans. Although some of the ligament could be depicted in fat-saturated image (c) with The femoral (arrow) and tibial guidelines showing the location MRI scans to visualize the anterolateral ligament (ALL) and (arrownearly head all) of portions the scans are (97.4 well %), it could only be observed in its of the coronal plane upon which describe its path and anatomic relations with lateral knee visualizedentirety in image abouta 71.7. The % of the tests. the ligament can be visualized. structures. meniscal (curved arrow) portion Note that it is possible to identify Materials and methods Thirty-nine 1.5-T MRI scans of the isKeywords not visualizedKnee on the. MRI same. Anterolateral ligament . PD weight the ALL on the axial plane as a knee were evaluated. The scans included an MRI knee proto- plane,sequence but it is. Anatomy identified on the thin structure with low signal col with T1-weighted sequences, T2-weighted sequences with subsequent image (b) (white arrow head) anterior to the fat saturation, and proton density (PD)-weighted fast spin- lateral collateral ligament echo sequences. Two radiologists separately reviewed all Introduction (white arrow) MRI scans to evaluate interobserver reliability. The ALL was divided into three portions for analyses: femoral, Segond [1] first mentioned the anterolateral ligament (ALL) in meniscal, and tibial. The path of the ALL was evaluated with the orthopedic literature in 1879. Despite having been de- regard to known structural parameters previously studied in scribed for over 120 years, this structure was only recently this region. named by Vieira et al. [2] in a study of the iliotibial tract that Results At least a portion of the ALL was visualized in 38 did not establish any ALL parameter with precision. Since (97.8 %) cases. The meniscal portion was most visualized 2012, anatomical studies have been conducted to define the (94.8 %), followed by the femoral (89.7 %) and the tibial origin and insertion parameters, their path, and other specifics. (79.4 %) portions. The three portions of the ALL were visu- Thus far, we know of four anatomical studies that have fo- alized in 28 (71.7 %) patients. The ALL was characterized cused specifically on the ALL [1, 3–5]. with greater clarity on the coronal plane and was visualized as The origin of the ALL is in the lateral femoral condyle, be close to the popliteus tendon while the other studiesa thin, linear found structure. TheSince T1-weighted its initial sequences description showed by a Segondanterior [1], and certain distal to knee the origin of the lateral collateral liga- it to be in close relation to the lateral collateral ligamentstatistically origin. inferior ligamentMRI studies visibility have frequency. referred With to the regard ability toment visualize (LCL) anda ligament between the LCL and the popliteal tendon. This structure might be important in the genesisto the of antero- T2 and PDstructure evaluations, in thealthough lateral the region visualization of the kneeThe [11 ALL–13 has], sometimes an oblique path anteriorly and inferiorly to the lateral knee instability. The authors of a biomechanicalfrequency study in PD wasreferred higher as for the the lateral three capsular portions of ligament, the tibia, and inserting have related on the this lateral meniscus and on the lateral tibial ligament, only the femoral portion showed significant values. condyle, 6.5 mm below the lateral tibial condyle chondral have shown the importance of this articular capsule region structure to the genesis of Segond fracture. However, none of surface [5]. with regard to rotational instability, although they did not these studies have evaluated the MRI’s abilityRecently, to visualize this structure the has become increasingly important; specifically address the ALL [6]. ALL in living people, nor have they described its imaging : : : Monaco et al. [6] suggested that it is associated with lesions of The above study suggests that injury to thisC. ligament P. Helito (* in-) J. R.appearance Pecora G. L. Camanho or its relationshipM. K. Demange to adjacentthe structures anterior cruciate in detail. ligament and the genesis of anterolateral Faculty of Medicine, Institute of Orthopedics and Traumatology, creases anterolateral instability and consequentlyKnee pivot-shift Surgery Division,This University is most of São likely Paulo, due São Paulo, to the Brazil lack of clinicalknee importance instability. Thus, given it has become important to conduct test grading, which is the primary predictor ofe-mail: functional [email protected] the ALL until recently. studies identifying the ALL using imaging. outcomes after ACL ligament reconstruction. However, only: :Our study showed that it was not possibleFew authors to visualize have cited radiological visualization pa- P. V. P. Helito H. P. Costa M. Bordalo-Rodrigues rameters specific to this structure using MRI scans [7–9]. a few studies have indicated the possibility of visualizingFaculty of Medicine, this Institutethe ALL of Orthopedics in all and knees Traumatology, using routine 1.5-T MRI protocols, Musculoskeletal Radiology Department, University of São Paulo, Furthermore, recent studies have suggested that the com- structure using the most commonly performed MRISão Paulo, protocols Brazil especially with regard to visualizingplete all identificationportions of of this the structure is not always possible. [7, 10]. structure.

Fig. 3 Two subsequent PD- weighted MRI scans on the coronal plane showing the ALL. The femoral (arrow) and tibial (arrow head) portions are well visualized in image a. The meniscal (curved arrow) portion is not visualized on the same plane, but it is identified on the subsequent image (b) Skeletal Radiol (2014) 43:1421–1427 DOI 10.1007/s00256-014-1966-7

SCIENTIFIC ARTICLE

Surg Radiol Anat

the tibia, with tibial insertion between Gerdy’s tubercle and previous anatomical studies of this structure was used the fibular head, approximately 5–10 mm below the articular [16, 18]. MRI evaluation of the anterolateral ligament ofcartilage the of the knee: lateral plateau [4, 6, 18, 28]. Initially, dissection of the skin and subcutaneous tissue Some authors have also described a secondary meniscal was performed, followed by tenotomy of the quadriceps insertion of the ALL, near the transition between the body tendon in its myotendinous junction, medial parapatellar assessment in routine 1.5-T scans and the anterior horn of the lateral meniscus [6, 18, 28]. opening of the retinaculum, and osteotomy of the anterior Helito et al. [18] described a bifurcation point near the tibial tuberosity with patellar reflection to access the middle of the ligament path, leading to its tibial insertion anterolateral knee without violating the adjacent extra-ar- Camilo Partezani Helito & Paulo Victor Partezani Helito & Hugo Pereira Costa & and its meniscal insertion. ticular soft tissues. Part of the retro-patellar fat of the Although the meniscal insertion has been described, region was excised for better viewing. Disinsertion of the Marcelo Bordalo-Rodrigues & José Ricardo Pecora & Gilberto Luis Camanho & including histological analysis in one study [18], studies iliotibial tract on Gerdy’s tubercle was performed. Marco Kawamura Demange such as the one by Dodds et al. [8] do not consider the ALL The popliteal muscle tendon (PMT) and the lateral meniscal insertion, statingSurg that Radiol the structureAnat in question has collateral ligament (LCL) were isolated carefully to avoid 1424 Skeletal Radiol (2014) 43:1421–1427only one tibial insertion.DOI 10.1007/s00276-015-1533-5 disrupting the ALL origin in the lateral epicondyle. Studies that consider this meniscal insertion have not After isolation of the structures, it was possible to thoroughly studied theORIGINAL anatomical parameters ARTICLE of this clearly visualize the capsular thickening in the anterolateral Fig. 2 MRI of the coronal plane structure; thus, the aim of this article is to study the ALL region of the knee compatible with ALL. To better visu- meniscal insertion in relation to the peripheral lateral alize the ALL fibers during dissection, the authors used to with PD-weighting (a) clearly Received: 19 March 2014 /Revised: 15 July 2014 /Accepted: 21 July 2014 /Published online: 3 Augustmeniscus 2014 and popliteal muscle tendon groove with histo- flex the knee and internally rotate the tibia, maneuvers that Surg Radiol Anat showing the ALL (asterisk). # ISS 2014 logical analysis of dissected specimens. make the ALL tense and easily visualized. The meniscal insertionAfter of ALL the isolation, knee the anterior anterolateral and posterior rootsTable of 1 Insertion ligament values of the anterolateral ligament (ALL) and popliteal muscle tendon groove in relation to the lateral meniscus Sagittal T1-weighted image the lateral meniscus were disinserted from the lateral tibial Mean Standard deviation Maximum Minimum (b) and axial T2-weighted Abstract Conclusion The ALLMethods can be visualized in routine 1.5-T MRI1 plateau, and the ALL was1 removed en bloc with the 2 Camilo Partezani Helito • Marcelomeniscus. Batista Bonadio • Thiago QueirozMeniscal Soares circumference• (mm) 97.4 13.9 114.6 77.2 Objective This study evaluated the ability of routine 1.5-T scans. Although some of the ligament could be depicted in 1 3 fat-saturated image (c) with Atotalof33unpairedfresh-frozenkneesofcadaversRoberto Freire da Mota e AlbuquerqueAfter removal• Renato of the anatomical Jose´ Mendonc specimen,¸a Natalinothe meniscusStart of ALL• insertion (%) 36.0 4.7 41.7 24.4 1 1 End of ALL1 insertion (%) 41.9 4.6 47.2 30.6 guidelines showing the location MRI scans to visualize the anterolateral ligament (ALL) and nearly all of the scans (97.4were used %), in it this could study.Jose only´ TheRicardo cadaversbe observed Pe´cora were all• inGilberto males its circumference, Luis Camanho the ALL• Marco insertion Kawamura points on the Demange external of the coronal plane upon which with 60.1 ± 10.2 years of age. None of the cadavers surface of the lateral meniscus, and the PMT grooveSize were of ALL insertion (mm) 5.6 1.2 8.2 4.0 describe its path and anatomic relations with lateral knee entirety in about 71.7 %used of had the any tests. history of previous surgeries, fractures or measured. The ALL insertion and the PMT grooveStart were of popliteal groove (%) 55.6 3.1 60.7 50.2 the ligament can be visualized. structures. infection around the knee that could alter its anatomy. quantified in relation to the measurement of the meniscusEnd of popliteal groove (%) 65.2 4.1 72.6 58.4 Distance between the ALL and the popliteal groove (mm) 12.9 4.0 21.1 9.1 Note that it is possible to identify Materials and methods Thirty-nine 1.5-T MRI scans of the Keywords Knee . MRIFor. theAnterolateral ALL dissection, ligament a protocol already. PD described weight in circumference. the ALL on the axial plane as a knee were evaluated. The scans included an MRI knee proto- sequence . Anatomy Furthermore, ALL injury may also be associated with thin structure with low signal col with T1-weighted sequences, T2-weighted sequences with Received: 5 December 2014 / Accepted: 29 July 2015 peripheral disinsertions of the lateral meniscus. Caterine et al. [4] have discussed this ALL motion relationship with (white arrow head) anterior to the fat saturation, and proton density (PD)-weighted fast spin- Ó Springer-Verlag France 2015 lateral collateral ligament the lateral meniscus, and Helito et al. [18] have raised the echo sequences. Two radiologists separately reviewed all Introduction possibility of the existence of these combined injuries in (white arrow) Abstract meniscal insertion and the beginning of the PMT groove discussions of their anatomical studies. Gadeyne et al. [11], MRI scans to evaluate interobserver reliability. The ALL Purpose The aim of this study is to characterize in detail averaged 12.9 mm. In the histological evaluation, in lon- in an epidemiological study on ACL injuries, concluded that lateral meniscus injuries usually occur at the time the meniscal insertion of the anterolateral ligament (ALL) gitudinal sections, we observed dense collagen fibers of the was divided into three portions for analyses: femoral, Segond [1] first mentioned the anterolateral ligament (ALL) in when the ACL is injured and not over time, as occurs with meniscal, and tibial. The path of the ALL was evaluated with the orthopedic literature in 1879. Despiteof the knee, having establishing been parameters de- regarding the circum- ligament inserting on the external surface of the meniscus. the medial meniscus [9, 25] and Claes et al. [5] showed that regard to known structural parameters previously studied in ference of the lateral meniscus and the popliteal muscle It is possible to observe a spreading of collagen fibers at the there is a high rate of ALL abnormalities in patients with scribed for over 120 years, this structuretendon (PMT) was only groove recently in addition to its histological analysis. moment of meniscal insertion. and ACL injury. One of the reasons for this combined ACL this region. named by Vieira et al. [2] in a studyMethods of the iliotibialA total of tract 33 knees that of cadavers were dissected. Conclusions The ALL meniscal insertion was found in all and lateral meniscus injury may be their close relationship with the ALL. Results At least a portion of the ALL was visualized in 38 did not establish any ALL parameterThe with ALL precision.and the lateral Since meniscus were removed en bloc. dissected specimens, beginning with approximately 36 % Recent ALL studies with MRI scans have clearly shown (97.8 %) cases. The meniscal portion was most visualized 2012, anatomical studies have beenAfter conducted removal to of define the anatomical the specimen, the meniscus of the meniscal outer diameter, 12.9 mm anterior to the this meniscal insertion [12, 19]. Helito et al. [19] showed circumference, the ALL insertion points on the external beginning of the PMT groove. The histological analysis that this ALL portion is more easily visualized. Gossner (94.8 %), followed by the femoral (89.7 %) and the tibial origin and insertion parameters, theirsurface path, and of the other lateral specifics. meniscus, and the PMT groove were confirmed the presence of true ligamentous tissue in the [12] also reported that meniscal insertion can often be the (79.4 %) portions. The three portions of the ALL were visu- Thus far, we know of four anatomicalmeasured. studies Eight that menisci have fo-were subjected to histological dissected specimens. only portion observed in exams. Fig. 3 Histological image of the longitudinal cross section of the The presence of a structure with bone origin and Fig. 1 Anatomical images of the insertion of the anterolateral ligament of the knee on the lateral meniscus, located at approximately 36–42 % of alized in 28 (71.7 %) patients. The ALL was characterized analysis. insertion of the anterolateral ligament (ALL) on the lateral meniscus meniscal insertion is not a novelty, and the meniscal por- cused specifically on thethe meniscal ALL circumference [1, 3–5]. (a) and occupying a mean space of 5.6 mm (b) (M). In this image, it is possible to observe the spreading of ligament Results The ALL was found in all dissections performed. Keywords Anterolateral ligament Lateral meniscus tion of the ALL could perform a function similar to the with greater clarity on the coronal plane and was visualized as fibers immediately before the meniscalÁ insertion Á The origin of the ALL is in theThe lateral ALL femoral insertion condyle, occurred macroscopically in the tran- Anatomy Histology function of the meniscus–femoral ligaments, originating in Á be close to the popliteus tendon while the other studiesa thin, linear found structure. TheSince T1-weighted its initial sequences description showed by a Segondanterior [1], and certain distal to knee the123 origin of thesition lateral between collateral the anterior liga- horn and the lateral meniscus With the growing search for improvements in recon- the medial femoral condyle and having a lateral meniscus body, specifically beginning at 36.0 % and ending at struction techniques for the ACL and the increased popu- insertion [13]. A possible assumption is that, in the same it to be in close relation to the lateral collateral ligamentstatistically origin. inferior ligamentMRI studies visibility have frequency. referred With to the regard ability toment visualize (LCL) anda ligament between the LCL and the popliteal tendon. way as the meniscus–femoral are agonists of the Posterior 41.9 % of the meniscal circumference, occupying a mean Introductionlarity of extra-articular reconstruction techniques to the T2 and PD evaluations, although the visualization The ALL has an oblique path anteriorly and inferiorly to the associated with intra-articular reconstructions, it is possible Cruciate Ligament, the meniscal portion of the ALL may This structure might be important in the genesis of antero- structure in the lateral region of the knee [11–13], sometimes area of 5.6 mm. The distance between the end of the ALL frequency in PD was higher for the three portions of the tibia, inserting on the lateral meniscus and on the lateral tibial that literature for ALL reconstruction will appear soon [14, be an agonist of the ACL [1]. According to biomechanical lateral knee instability. The authors of a biomechanical study referred as the lateral capsular ligament, and have related this Recent anatomical26, 27]. Websites studies specializing have clearly in surgical described technique thevideos, studies by Monaco et al. [21], where the anterolateral ligament, only the femoral portion showed significant values. condyle, 6.5 mm below the lateral tibial condyle chondral anterolateralsuch ligament as ‘‘Vumedi’’, (ALL) of already the knee present [4 several, 6, 8, ALL16, 18 recon-, capsule was injured on the ALL topography, the ALL as a have shown the importance of this articular capsule region structure to the genesis of Segond fracture. However, none of struction techniques that will be published in specialized whole has proven to be an important structure in the & Camilo Partezani Helito 28]. This ligament has gained importance due to its pos- surface [5]. journals in the near future. Radiographic parameters for rotational stability of the tibia in relation to the femur, but [email protected] sible relationship to the injuries of the anterior cruciate with regard to rotational instability, although they did not these studies have evaluated the MRI’s abilityRecently, to visualize this structure the has become increasingly important; ligament reconstruction have already been established [17, there are no specific tests yet for each of its portions. ligament (ACL),22]. a widely studied topic in the orthopedic Biomechanical studies have been conducted by our group 1 Knee Surgery Division, Department of Orthopaedics and specifically address the ALL [6]. ALL in living people, nor have they describedMonaco et al. its [6 imaging] suggested that it is associated with lesions of literature. to confirm this association. Traumatology, Institute of Orthopedics and Traumatology, At the time of reconstruction, in addition to the bone C. P. Helito (*) : J. R. Pecora : G. L. Camanho : M. K. Demange The visualization of this meniscal insertion during sur- the anterior cruciate ligament and the genesisHospital and ofClinics, anterolateral Faculty of Medicine, University of Sa˜o Even thoughattachment this ligament points of has the been ligament first on cited theby femur Segond and tibia The above study suggests that injury to this ligament in- appearance or its relationship to adjacent structures in detail. gical procedures has not been well established. Sonnery- Faculty of Medicine, Institute of Orthopedics and Traumatology, Paulo (IOT-HCFMUSP), Rua Dr. Ovı´dio Pires de Campos, in 1879 [23],and only knowledge recently about it has the been ALL focus isometricity of attention. [15], the knee instability. Thus, it has become important to conduct meniscal attachment may also be important. Biomechani- Cottet et al. [24] demonstrated an arthroscopic technique creases anterolateral instability and consequentlyKnee pivot-shift Surgery Division,This University is most of São likely Paulo, due São Paulo, to the Brazil lack of clinical importance given 333, Cerqueira Cesar, Sa˜o Paulo, SP CEP: 05403-010, Brazil Several authors named the ligament that connects the cal studies are being conducted to test whether there is a for ALL visualization; however, they only managed to e-mail: [email protected] studies identifying the ALL using imaging.2 test grading, which is the primary predictor of functional to the ALL until recently. Department of Orthopaedics and Traumatology, Institute of femur to thesignificant tibia on the function anterolateral of this insertion portion in of the the genesis knee of visualize the most proximal portion of the ligament. Few authors have cited radiologicalOrthopedics visualization and Traumatology, pa- Hospital and Clinics, Faculty capsule in theanterolateral past and theinstability ALL of had the different knee. names, such According to the anatomical and resonance parameters outcomes after ACL ligament reconstruction. However,P. V. P. Helito only: H. P. Costa :OurM. Bordalo-Rodrigues study showed that it was not possible to visualize of Medicine, University of Sa˜o Paulo (IOT-HCFMUSP), as lateral capsular ligament [20] and anterior oblique band rameters specific to this structure usingSa˜o Paulo,MRI Brazil scans [7–9]. Faculty of Medicine, Institute of Orthopedics and Traumatology, [3], but no author focused exclusively in its anatomy until a few studies have indicated the possibility of visualizing this the ALL in all knees using routine 1.5-T MRI protocols, 3 Musculoskeletal Radiology Department, University of São Paulo, Furthermore, recent studies have suggestedPathological that Anatomy the Division, com- Department of Orthopaedics the past few years.123 structure using the most commonly performed MRI protocols especially with regard to visualizing all portions of this and Traumatology, Institute of Orthopedics and São Paulo, Brazil plete identification of the structure isTraumatology, not always Hospital possible. and Clinics, Faculty of Medicine, According to existing studies, the ALL origin is near the [7, 10]. structure. University of Sa˜o Paulo (IOT-HCFMUSP), Sa˜o Paulo, Brazil lateral epicondyle and follows an antero-inferior path toward

123 Fig. 3 Two subsequent PD- weighted MRI scans on the coronal plane showing the ALL. The femoral (arrow) and tibial (arrow head) portions are well visualized in image a. The meniscal (curved arrow) portion is not visualized on the same plane, but it is identified on the subsequent image (b) 1424 Skeletal Radiol (2014) 43:1421–1427

Fig. 2 MRI of the coronal plane with PD-weighting (a) clearly showing the ALL (asterisk). Sagittal T1-weighted image (b) and axial T2-weighted fat-saturated image (c) with guidelines showing the location of the coronal plane upon which the ligament can be visualized. Note that it is possible to identify the ALL on the axial plane as a thin structure with low signal (white arrow head) anterior to the lateral collateral ligament (white arrow)

be close to the popliteus tendon while the other studies found Since its initial description by Segond [1], certain knee it to be in close relation to the lateral collateral ligament origin. MRI studies have referred to the ability to visualize a ligament This structure might be important in the genesis of antero- structure in the lateral region of the knee [11–13], sometimes lateral knee instability. The authors of a biomechanical study referred as the lateral capsular ligament, and have related this have shown the importance of this articular capsule region structure to the genesis of Segond fracture. However, none of with regard to rotational instability, although they did not these studies have evaluated the MRI’s ability to visualize the specifically address the ALL [6]. ALL in living people, nor have they described its imaging The above study suggests that injury to this ligament in- appearance or its relationship to adjacent structures in detail. creases anterolateral instability and consequently pivot-shift This is most likely due to the lack of clinical importance given test grading,• which Do the images visualized in MRI correspond to is the primary predictor of functional to the ALL until recently. outcomes after ACL ligament reconstruction. However, only Our study showed that it was not possible to visualize a few studies have indicated the possibility of visualizing this the ALL in all knees using routine 1.5-T MRI protocols, structure using the mostthe ALL anatomy? commonly performed MRI protocols especially with regard to visualizing all portions of this [7, 10]. structure.

Fig. 3 Two subsequent PD- weighted MRI scans on the coronal plane showing the ALL. The femoral (arrow) and tibial (arrow head) portions are well visualized in image a. The meniscal (curved arrow) portion is not visualized on the same plane, but it is identified on the subsequent image (b) Original Research

Correlation of Magnetic Resonance Imaging With Knee Anterolateral Ligament Anatomy

A Cadaveric Study

Camilo Partezani Helito,*† MD, Paulo Victor Partezani Helito,‡ MD, Marcelo Batista Bonadio,† MD, Jose´ Ricardo Pe´ cora,† MD, PhD, Marcelo Bordalo-Rodrigues,‡ MD, Gilberto Luis Camanho,† MD, PhD, and Marco Kawamura Demange,† MD, PhD Investigation performed at the Department of Orthopedics and Traumatology, Faculty4 Helito of et al The Orthopaedic Journal of Sports Medicine The OrthopaedicThe Orthopaedic JournalMedicine, Journalof Sports of UniversityMedicine Sports Medicine of Sa˜o Paulo, Sa˜o Paulo,AnatomyAnatomy Brazil and and MRI MRI of of the the Anterolateral Ligament Ligament3 3

Background: Anatomic and magnetic resonance imaging (MRI) studies have recently characterized the knee anterolateral ligament (ALL). So far, no study has focused on confirming whether the evaluated MRI parameters truly correspond with ALL TABLE 2 anatomy. Measurements of Anatomic Specimens and Purpose: To assess the validity of MRI in detecting the ALL using an anatomic evaluation as reference. MRI Scans With Spearman Correlation Coefficient a Study Design: Descriptive laboratory study. for the Investigated Variables Methods: Atotalof13cadaverickneesweresubjectedtoMRIandthentoanatomicdissection.Dissectionwasperformed according to previous anatomic study methodology. MRIs were performed with a 0.6- to 1.5-mm slice thickness and prior saline Method, Mean ± SD injection. The following variables were analyzed: distance from the origin of the ALL to the origin of the lateral collateral ligament (LCL), distance from the origin of the ALL to its bifurcation point, maximum length of the ALL, distance from the tibial insertion of the Anatomy MRI r P ALL to the articular surface of the tibia, ALL thickness, and ALL width. The 2 sets of measurements were analyzed using the Spearman correlation coefficient (r)andBland-Altmanplots. Distance from origin 3.77 ± 1.481 3.92 ± 1.935 0.932 <.001 to the LCL, mm Results: The ALL was clearly observed in all dissected knees and MRI scans. It originated anterior and distal to the LCL, close to the lateral epycondile center, and showed an anteroinferior path toward the tibia, inserting between the Gerdy tubercle and the Distance from origin 18.46 ± 3.406 17.92 ± 2.691 0.939 <.001 fibular head, around 5 mm under the lateral plateau. The r values tended to increase together for all studied variables between the 2 to the bifurcation methods, and all were statistically significant, except for thickness (P .077). Bland-Altman plots showed a tendency toward a point, mm reduction of ALL thickness and width by MRI compared with anatomic¼ dissection. Distance from the 5.38 ± 1.446 5.46 ± 1.266 0.877 <.001 Conclusion: MRI scanning as described can accurately assess the ALL and demonstrates characteristics similar to those seen insertion to the under anatomic dissection. tibial plateau, mm Clinical Relevance: MRI can accurately characterize the ALL in the anterolateral region of the knee, despite the presence of Length, mm 36.62 ± 4.053 36.15 ± 3.76 0.943 <.001 structures that might overlap and thus cause confusion when making assessments based on imaging methods. Thickness, mm 2.23 ± 0.439 1.54 ± 0.519 0.507 .077 Width, mm 6.08 1.038 5.23 0.725 0.875 <.001 Keywords: anterolateral ligament; magnetic resonance imaging; MRI; anatomy ± ± ar, Spearman correlation coefficient; LCL, lateral collateral Figure 2. Axial proton density–weighted section of the right8,11,17 knee Recent anatomic studies have clearly establishedshowing the the anterolateralhead ligament and (dotted Gerdy oval) tubercle. located anterior toSome authors also found ligament; MRI, magnetic resonance imaging. 9 landmarks for locating the origin and insertion ofthe the lateral knee collateral ligamentan attachment (asterisk) at the to level the of lateral the lateral meniscus. The ALL has Figure 1. anterolateralCoronal proton ligament density–weighted (ALL), section as well of as the its pathFigurefemoral and 2. char-Axial condyle proton (LFC). density–weightedrecently been praised section of for the its right possible knee role as a stabilizer of 1,4,6,10,15,24,28 Figure 4. Anatomic photograph of a cadaveric left knee from right knee showingacteristics. the origin of the lateralAccording collateral ligament to the literature,showing the theanterolateralknee ligament rotation, (dotted oval) according located anteriorto biomechanical to studies per- the lateral collateral ligament (asterisk) at the level20-22 of the lateral a lateral view showing the origin of the anterolateral ligament (star); the originorigin (arrow), of the bifurcation ALL is close point to (asterisk), the center and tibial of the lateral epicon- formed by Monaco et al and clinical studies that have RESULTS Figure 1.insertionCoronal (arrowhead)dyle, proton between density–weighted of the the anterolateral origin section of ligament; the lateralof theand the collateralfemoral ligament condyle (LFC). added lateral procedures to conventional(ALL) intra-articular (1) located close to the origin of the lateral collateral liga- right kneedistance showing from the(LCL) the origin tibial and of insertion the the lateral insertion to the collateral lateral of theplateau ligament popliteus (dotted muscle tendon anterior cruciate ligament (ACL) reconstructions.5,26,27 line). LFC, lateral femoral condyle; LM, lateral meniscus; LTP, ment (LCL) (4). The ALL travels in an anteroinferior direction The ALL was clearly observed on macroscopic inspection (star); the origin (arrow),(PMT) bifurcation or slightly point proximal (asterisk), and and posterior tibial to the lateral epi- Despite the anatomic and biomechanical studies avail- lateral tibial plateau. toward the tibia and bifurcates (asterisk) before its insertions insertion (arrowhead)condyle. of the Theanterolateral ALL then ligament; goes in and an anteroinferior the direction able, few studies have assessed the ALL using imaging (gross anatomy) in all 13 dissected knees. The entire path in the meniscus (2) and the tibia (3). GT, Gerdy tubercle; FH, distance from the tibialtoward insertion the tibia,to the lateralhaving plateau an insertion (dotted between the fibular methods, particularly magnetic resonance imaging (MRI), of the ALL was also visualized in all of the MRI scans line). LFC,LCL, lateral including femoralthe condyle; remaining LM, lateral portions meniscus; of the lateral LTP, cap- which is the standard method for assessmentfibular of knee head. liga- sule, for better visualization. All dissections were per- (Figures 4 and 5). The anatomic and MRI measurements lateral tibial plateau. ments.1,2,12,14 Three recent studies investigated the ALL formed byThe 2 authors Orthopaedic together Journal (C.P.H., of Sports M.B.B.). Medicine, 3(12), 2325967115621024 are provided in Table 2. using MRI, 2 of which examined individuals without a liga- Once theDOI: ALL 10.1177/2325967115621024 was isolated, the following measurements The attachment of the ALL in the lateral epicondyle LCL, includingwere performed theª remainingThe with Author(s) a digital portions 2015 caliper: of the distance lateral from cap- the ori- ment injury and the third examined individuals with an sule, forgin better of the visualization. ALL to the origin All of the dissections LCL in the were lateral per- femoral region was found anterior and distal to the attachment of formed bycondyle, 2 authors distanceThis together open-access from (C.P.H., the article origin is M.B.B.).published of the ALL and to distributed its bifurca- under the Creative Commons Attribution - NonCommercial - No Derivatives License (http://creativecommons.org/ the LCL. The ligament then coursed anterodistally to the Once thetion ALL point, waslicenses/by-nc-nd/3.0/), distance isolated, from the the following tibial which insertion permits measurements the of noncommercial the ALL to use, distribution, and reproduction of the article in any medium, provided the original author and source are the lateralcredited. tibial plateau You may cartilage, not alter, transform, total length or build of theupon ALL this article without the permission of the Author(s). For reprints and permission queries, please visit SAGE’s Web site proximal anterolateral tibial region, attaching between the were performed with a digital caliper: distance from the ori- (measuredat as http://www.sagepub.com/journalsPermissions.nav. the distance between its origin and tibial Gerdy tubercle and the fibular head 5.3 mm under the lat- gin of the ALLinsertion), to the and origin thickness of the andLCL width in the of lateral the ALL—the femoral same condyle, distance from the origin of the ALL to its bifurca- eral tibial plateau. Close proximity to the lateral meniscus measurements that had been performed on the MRI scans. 1 tion point,Measurements distance from were the performed tibial insertion with approximately of the ALL to 15Downloaded of from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 was observed during its course. the lateralknee tibial flexion plateau and neutral cartilage, rotation, total similarlength toof the the knee ALL posi- Through use of MRI, the ALL was characterized with (measuredtion as in the the distance MRI studies. between The width its and origin thickness and tibial measure- greater clarity on the coronal and axial planes as a thin lin- insertion),ments and thickness were performed and width above of the the ALL—the level of the same lateral measurementsmeniscus, that similar had been to the performed measurements on the performedMRI scans. using ear structure with a thickness varying between 1 and 2 mm MRI. Anatomic measurements were performed by 2 authors Measurements were performed with approximately 15 of Figure 3. Sagittal proton density–weighted section of the right and surrounded by adipose tissue or synovial fluid. The ori- independently (C.P.H., M.B.B.). Interobserver correlation of knee flexion and neutral rotation, similar to the knee posi- knee showing the relationship between the anterolateral liga- measurements was calculated. gin of the ALL on the outer face of the lateral femoral con- tion in the MRI studies. The width and thickness measure- ment (ALL) and the lateral collateral ligament (LCL). The origins The 2 sets of measurements (MRI and anatomic speci- dyle was located immediately anterior to the LCL. ments were performed above the level of the lateral of both are close to the lateral femoral epicondyle (LFE), but the mens) were subjected to statistical analysis using SPSS ALL runs anteriorly to the LCL and inserts in the lateral tibial pla- meniscus, similar to the measurements performed using The ALL showed an anteroinferior path, superficial to the teau (LTP) while the insertion of the LCL is in the fibular head (FH). MRI. Anatomic measurements were performed by 2 authors Figure 3. Sagittal proton density–weighted section of the right origin of the popliteal tendon groove. A bifurcation could be independently (C.P.H., M.B.B.). InterobserverDownloaded correlation from ojs.sagepub.com of at MUSEUknee PAULISTA showing USP on December the 23, relationship 2015 between the anterolateral liga- observed above the lateral inferior geniculate artery, leading measurements was calculated. ment (ALL) and the lateral collateral ligament (LCL). The origins to a meniscus and a tibial insertion. The tibial segment of the The 2 sets of measurements (MRI and anatomic speci- of both are close to the lateral femoral epicondyle (LFE), but the mens) were subjected to statistical analysis using SPSS ALL was inserted 5.4 mm beneath the plane of the lateral ALL runs anteriorly to the LCL and inserts in the lateral tibial pla- tibial plateau and under the insertion of the iliotibial tract. teau (LTP) while the insertion of the LCL is in the fibular head (FH). Figure 5. Anatomic photograph of a cadaveric left knee from an anterolateral view showing the origin (1) and tibial insertion Interobserver correlation for anatomic measurements Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 (3) of the knee anterolateral ligament (ALL). The ALL is sur- varied between 0.86 and 0.96. Intra- and interobserver cor- rounded by the blue suture. The lateral meniscus is indicated relation for MRI measurements were 0.77 to 0.93 and 0.85 by (2). LCL, lateral collateral ligament; LFC, lateral femoral to 0.90, respectively. condyle. With regard to the correlation between the anatomic and MRI findings, the correlation coefficient (r) was between 0 20.0 software (IBM Corp). The Spearman correlation and 1 for all studied variables, denoting that the 2 values coefficient (r)wascalculatedwiththecorresponding95% tended to increase or decrease together. All values were sta- confidence interval (P <.05).Inaddition,acomparative tistically significant except for ALL thickness (P .077), ¼ analysis of the correlation between the 2 sets of measure- which showed a minor correlation coefficient (r 0.507) ¼ ments was performed using Bland-Altman plots. between methods.

Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 4 Helito et al The Orthopaedic Journal of Sports Medicine

TABLE 2 Measurements of Anatomic Specimens and MRI Scans With Spearman Correlation Coefficient for the Investigated Variablesa

Method, Mean ± SD The Orthopaedic Journal of Sports Medicine Anatomy and MRI of the Anterolateral Ligament 3 Anatomy MRI r P

Distance from origin 3.77 ± 1.481 3.92 ± 1.935 0.932 <.001 to the LCL, mm Distance from origin 18.46 ± 3.406 17.92 ± 2.691 0.939 <.001 to the bifurcation point, mm Distance from the 5.38 ± 1.446 5.46 ± 1.266 0.877 <.001 insertion to the tibial plateau, mm Length, mm 36.62 ± 4.053 36.15 ± 3.76 0.943 <.001 Original Research Thickness, mm 2.23 ± 0.439 1.54 ± 0.519 0.507 .077 Width, mm 6.08 ± 1.038 5.23 ± 0.725 0.875 <.001

Correlation of Magnetic Resonance Imaging ar, Spearman correlation coefficient; LCL, lateral collateral With Knee Anterolateral Ligament Anatomy ligament; MRI, magnetic resonance imaging. Figure 4. Anatomic photograph of a cadaveric left knee from a lateral view showing the origin of the anterolateral ligament A Cadaveric Study RESULTS (ALL) (1) located close to the origin of the lateral collateral liga- † ‡ † Camilo Partezani Helito,* MD, Paulo Victor Partezaniment Helito, (LCL)MD, (4). Marcelo The ALL Batista travels Bonadio, in an anteroinferiorMD, direction The ALL was clearly observed on macroscopic inspection Jose´ Ricardo Pe´ cora,† MD, PhD, Marcelo Bordalo-Rodrigues,toward the tibia‡ MD, and bifurcates (asterisk) before its insertions † † (gross anatomy) in all 13 dissected knees. The entire path FigureGilberto 2. Axial Luis proton Camanho, density–weightedMD, section PhD, of and the right Marco knee Kawamura Demange, MD, PhD in the meniscus (2) and the tibia (3). GT, Gerdy tubercle; FH, of the ALL was also visualized in all of the MRI scans showingInvestigation the anterolateral performed ligament (dotted at the oval) Department located anterior of to Orthopedics and Traumatology, Faculty of fibular4 Helito head. et al The Orthopaedic Journal of Sports Medicine the lateralMedicine, collateral University ligament (asterisk) of Sa˜o at Paulo, the level Sa of˜o the Paulo, lateral Brazil (Figures 4 and 5). The anatomic and MRI measurements Figure 1. Coronal proton density–weighted section of the femoral condyle (LFC). are provided in Table 2. right knee showing the origin of the lateral collateral ligament Background: Anatomic and magnetic resonance imaging (MRI) studies have recently characterized the knee anterolateral The attachment of the ALL in the lateral epicondyle (star); the origin (arrow), bifurcation point (asterisk), and tibial ligament (ALL). So far, no study has focused on confirming whether the evaluated MRI parameters truly correspond with ALL TABLE 2 insertion (arrowhead) of the anterolateral ligament; and the anatomy. Measurementsregion of Anatomic was found Specimens anterior and and distal to the attachment of distance from the tibial insertion to the lateral plateau (dotted Purpose: To assess the validity of MRI in detecting the ALL using an anatomic evaluation as reference. MRI Scans Withthe Spearman LCL. TheCorrelation ligament Coefficient then coursed anterodistally to the line). LFC, lateral femoral condyle; LM, lateral meniscus; LTP, a Study Design: Descriptive laboratory study. for the Investigated Variables lateral tibial plateau. proximal anterolateral tibial region, attaching between the Methods: Atotalof13cadaverickneesweresubjectedtoMRIandthentoanatomicdissection.Dissectionwasperformed according to previous anatomic study methodology. MRIs were performed with a 0.6- to 1.5-mm slice thickness and prior saline GerdyMethod, tubercle Mean ± andSD the fibular head 5.3 mm under the lat- LCL, including the remaining portions of the lateral cap- injection. The following variables were analyzed: distance from the origin of the ALL to the origin of the lateral collateral ligament eralAnatomy tibial plateau. MRI Closer proximityP to the lateral meniscus sule, for better visualization. All dissections were per- (LCL), distance from the origin of the ALL to its bifurcation point, maximum length of the ALL, distance from the tibial insertion of the ALL to the articular surface of the tibia, ALL thickness, and ALL width. The 2 sets of measurements were analyzed using the was observed during its course. formed by 2 authors together (C.P.H., M.B.B.). Distance from origin 3.77 ± 1.481 3.92 ± 1.935 0.932 <.001 Spearman correlation coefficient ( )andBland-Altmanplots. Once the ALL was isolated, the following measurements r to the LCL, mm Through use of MRI, the ALL was characterized with were performed with a digital caliper: distance from the ori- Results: The ALL was clearly observed in all dissected knees and MRI scans. It originated anterior and distal to the LCL, close to Distance from origin greater18.46 ± 3.406 clarity 17.92 on± 2.691 the coronal0.939 <.001 and axial planes as a thin lin- gin of the ALL to the origin of the LCL in the lateral femoral the lateral epycondile center, and showed an anteroinferior path toward the tibia, inserting between the Gerdy tubercle and the to the bifurcation fibular head, around 5 mm under the lateral plateau. The values tended to increase together for all studied variables between the 2 condyle, distance from the origin of the ALL to its bifurca- r point, mm ear structure with a thickness varying between 1 and 2 mm methods, and all were statistically significant, except for thickness (P .077). Bland-Altman plots showed a tendency toward a Distance from the 5.38 ± 1.446 5.46 ± 1.266 0.877 <.001 tion point, distance from the tibial insertion of the ALL to reduction of ALL thickness and width by MRI compared with anatomic¼ dissection. and surrounded by adipose tissue or synovial fluid. The ori- the lateral tibial plateau cartilage, total length of the ALL insertion to the Conclusion: MRI scanning as described can accurately assess the ALL and demonstrates characteristics similar to those seen gin of the ALL on the outer face of the lateral femoral con- (measured as the distance between its origin and tibial tibial plateau, mm under anatomic dissection. insertion), and thickness and width of the ALL—the same Length, mm dyle36.62 was± 4.053 located 36.15 ± 3.76 immediately 0.943 <.001 anterior to the LCL. measurements that had been performed on the MRI scans. Clinical Relevance: MRI can accurately characterize the ALL in the anterolateral region of the knee, despite the presence of Thickness, mm 2.23The± ALL0.439 showed 1.54 ± 0.519 an 0.507 anteroinferior .077 path, superficial to the structures that might overlap and thus cause confusion when making assessments based on imaging methods. Width, mm 6.08 ± 1.038 5.23 ± 0.725 0.875 <.001 Measurements were performed with approximately 15 of knee flexion and neutral rotation, similar to the knee posi- Keywords: anterolateral ligament; magnetic resonance imaging; MRI; anatomy origin of the popliteal tendon groove. A bifurcation could be ar, Spearman correlation coefficient; LCL, lateral collateral tion in the MRI studies. The width and thickness measure- observed above the lateral inferior geniculate artery, leading ligament; MRI, magnetic resonance imaging. ments were performed above the level of the lateral Recent anatomic studies have clearly established the head and Gerdy tubercle.8,11,17 Some authors also found to a meniscus and a tibial insertion. The tibial segment of the meniscus, similar to the measurements performed using landmarks for locating the origin and insertion of the knee an attachment to the lateral meniscus.9 The ALL has Figure 4. Anatomic photograph of a cadaveric left knee from MRI. Anatomic measurements were performed by 2 authors anterolateral ligament (ALL), as well as its path and char- recently been praised for its possible role as a stabilizer of ALL was inserted 5.4 mm beneath the plane of the lateral Figureacteristics. 3. Sagittal1,4,6,10,15,24,28 proton density–weightedAccording to the section literature, of the theright aknee lateral rotation, view showing according the to origin biomechanical of the anterolateral studies per- ligament independently (C.P.H., M.B.B.). Interobserver correlation of knee showing the relationship between the anterolateral liga- Figure 5. Anatomic20-22 photograph of a cadaveric left kneeRESULTS from tibial plateau and under the insertion of the iliotibial tract. measurements was calculated. origin of the ALL is close to the center of the lateral epicon- (ALL)formed (1) located by Monaco close et al to theand origin clinical of the studies lateral that collateral have liga- mentdyle, (ALL) between and the the lateral origin collateral of the lateral ligament collateral (LCL). The ligament origins anmentadded anterolateral (LCL) lateral (4). procedures The view ALL travels toshowing conventional in an the anteroinferior intra-articular origin (1) direction and tibial insertion Interobserver correlation for anatomic measurements The 2 sets of measurements (MRI and anatomic speci- 5,26,27 The ALL was clearly observed on macroscopic inspection of both(LCL) are and close the tothe insertion lateral of femoral the popliteus epicondyle muscle (LFE), tendon but the towardanterior the cruciate tibia and ligament bifurcates (ACL) (asterisk) reconstructions. before its insertions mens) were subjected to statistical analysis using SPSS ALL(PMT) runs anteriorly or slightly to theproximal LCL and and inserts posterior in the to thelateral lateral tibial epi- pla- (3) ofDespite the kneethe anatomic anterolateral and biomechanical ligament studies (ALL). avail- The ALL(gross is sur- anatomy) invaried all 13 dissected between knees. 0.86 The and entire 0.96. path Intra- and interobserver cor- in the meniscus (2) and the tibia (3). GT, Gerdy tubercle; FH, teaucondyle. (LTP) while The the ALL insertion then goes of the in LCL an anteroinferior is in the fibular directionhead (FH). roundedable, few by studies the have blue assessed suture. the The ALL lateralusing imaging meniscus is indicatedof the ALL was alsorelation visualized for in MRI all of measurements the MRI scans were 0.77 to 0.93 and 0.85 fibular head. toward the tibia, having an insertion between the fibular bymethods, (2). LCL, particularly lateral magnetic collateral resonance ligament; imaging (MRI), LFC, lateral(Figures femoral 4 and 5).to The 0.90, anatomic respectively. and MRI measurements Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 which is the standard method for assessment of knee liga- are provided in Table 2. ments.1,2,12,14 Three recent studies investigated the ALL The Orthopaedic Journal of Sports Medicine, 3(12), 2325967115621024 condyle. The attachment ofWith the ALL regard in the to lateral the correlation epicondyle between the anatomic and DOI: 10.1177/2325967115621024 using MRI, 2 of which examined individuals without a liga- region was found anteriorMRI findings, and distal tothe the correlation attachment of coefficient ( ) was between 0 ª The Author(s) 2015 ment injury and the third examined individuals with an r 20.0 software (IBM Corp). The Spearman correlationthe LCL. The ligamentand then 1 for coursed all studied anterodistally variables, to the denoting that the 2 values This open-access article is published and distributed under the Creative Commons Attribution - NonCommercial - No Derivatives License (http://creativecommons.org/ proximal anterolateral tibial region, attaching between the licenses/by-nc-nd/3.0/), which permits the noncommercial use, distribution, and reproductioncoefficient of the article ( inr)wascalculatedwiththecorresponding95 any medium, provided the original author and source are Gerdy tubercle% andtended the fibular to head increase 5.3 mm or under decrease the lat- together. All values were sta- credited. You may not alter, transform, or build upon this article without the permission of the Author(s). For reprints and permission queries, please visit SAGE’s Web site at http://www.sagepub.com/journalsPermissions.nav. confidence interval (P <.05).Inaddition,acomparativeeral tibial plateau.tistically Close proximity significant to the lateral except meniscus for ALL thickness (P .077), ¼ analysis of the correlation between the 2 sets of measure-was observed duringwhich its course. showed a minor correlation coefficient (r 0.507) 1 Through use of MRI, the ALL was characterized with ¼ Downloaded from ojs.sagepub.com at MUSEUments PAULISTA USP was on December performed 23, 2015 using Bland-Altman plots. greater clarity on thebetween coronal and methods. axial planes as a thin lin- ear structure with a thickness varying between 1 and 2 mm and surrounded by adipose tissue or synovial fluid. The ori- gin of the ALL on the outer face of the lateral femoral con- Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 dyle was located immediately anterior to the LCL. The ALL showed an anteroinferior path, superficial to the origin of the popliteal tendon groove. A bifurcation could be observed above the lateral inferior geniculate artery, leading to a meniscus and a tibial insertion. The tibial segment of the ALL was inserted 5.4 mm beneath the plane of the lateral Figure 5. Anatomic photograph of a cadaveric left knee from tibial plateau and under the insertion of the iliotibial tract. an anterolateral view showing the origin (1) and tibial insertion Interobserver correlation for anatomic measurements (3) of the knee anterolateral ligament (ALL). The ALL is sur- varied between 0.86 and 0.96. Intra- and interobserver cor- rounded by the blue suture. The lateral meniscus is indicated relation for MRI measurements were 0.77 to 0.93 and 0.85 by (2). LCL, lateral collateral ligament; LFC, lateral femoral to 0.90, respectively. condyle. With regard to the correlation between the anatomic and MRI findings, the correlation coefficient (r) was between 0 20.0 software (IBM Corp). The Spearman correlation and 1 for all studied variables, denoting that the 2 values coefficient (r)wascalculatedwiththecorresponding95% tended to increase or decrease together. All values were sta- confidence interval (P <.05).Inaddition,acomparative tistically significant except for ALL thickness (P .077), ¼ analysis of the correlation between the 2 sets of measure- which showed a minor correlation coefficient (r 0.507) ¼ ments was performed using Bland-Altman plots. between methods.

Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 The Orthopaedic Journal of Sports Medicine Anatomy and MRI of the Anterolateral Ligament 3

Original Research

Correlation of Magnetic Resonance Imaging With Knee Anterolateral Ligament Anatomy

A Cadaveric Study

Camilo Partezani Helito,*† MD, Paulo Victor Partezani Helito,‡ MD, Marcelo Batista Bonadio,† MD, Jose´ Ricardo Pe´ cora,† MD, PhD, Marcelo Bordalo-Rodrigues,‡ MD, † † FigureGilberto 2. Axial Luis proton Camanho, density–weightedMD, section PhD, of and the right Marco knee Kawamura Demange, MD, PhD showingInvestigation the anterolateral performed ligament (dotted at the oval) Department located anterior of to Orthopedics and Traumatology, Faculty of 4 Helito et al The Orthopaedic Journal of Sports Medicine the lateralMedicine, collateral University ligament (asterisk) of Sa˜o at Paulo, the level Sa of˜o the Paulo, lateral Brazil4 Helito et al The Orthopaedic Journal of Sports Medicine Figure 1. Coronal proton density–weighted section of the femoral condyle (LFC). right knee showing the origin of the lateral collateral ligament Background: Anatomic and magnetic resonance imaging (MRI) studies have recently characterized the knee anterolateral (star); the origin (arrow), bifurcation point (asterisk), and tibial ligament (ALL). So far, no study has focused on confirming whether the evaluated MRI parameters truly correspond with ALL TABLETABLE 2 2 insertion (arrowhead) of the anterolateral ligament; and the anatomy. MeasurementsMeasurements of of Anatomic Anatomic Specimens Specimens and and distance from the tibial insertion to the lateral plateau (dotted Purpose: To assess the validity of MRI in detecting the ALL using an anatomic evaluation as reference. MRIMRI Scans Scans With With Spearman Spearman Correlation Correlation Coefficient Coefficient line). LFC, lateral femoral condyle; LM, lateral meniscus; LTP, a Study Design: Descriptive laboratory study. for the Investigated Variables a lateral tibial plateau. for the Investigated Variables Methods: Atotalof13cadaverickneesweresubjectedtoMRIandthentoanatomicdissection.Dissectionwasperformed Method, Mean ± SD according to previous anatomic study methodology. MRIs were performed with a 0.6- to 1.5-mm slice thickness and prior saline Method, Mean ± SD LCL, including the remaining portions of the lateral cap- injection. The following variables were analyzed: distance from the origin of the ALL to the origin of the lateral collateral ligament Anatomy MRI r P sule, for better visualization. All dissections were per- (LCL), distance from the origin of the ALL to its bifurcation point, maximum length of the ALL, distance from the tibial insertion of the Anatomy MRI r P ALL to the articular surface of the tibia, ALL thickness, and ALL width. The 2 sets of measurements were analyzed using the formed by 2 authors together (C.P.H., M.B.B.). Distance from origin 3.77 ± 1.481 3.92 ± 1.935 0.932 <.001 Spearman correlation coefficient ( )andBland-Altmanplots. Distance from origin 3.77 1.481 3.92 1.935 0.932 <.001 Once the ALL was isolated, the following measurements r to the LCL, mm ± ± to the LCL, mm were performed with a digital caliper: distance from the ori- Results: The ALL was clearly observed in all dissected knees and MRI scans. It originated anterior and distal to the LCL, close to Distance from origin 18.46 ± 3.406 17.92 ± 2.691 0.939 <.001 gin of the ALL to the origin of the LCL in the lateral femoral the lateral epycondile center, and showed an anteroinferior path toward the tibia, inserting between the Gerdy tubercle and the Distanceto the bifurcation from origin 18.46 ± 3.406 17.92 ± 2.691 0.939 <.001 fibular head, around 5 mm under the lateral plateau. The values tended to increase together for all studied variables between the 2 condyle, distance from the origin of the ALL to its bifurca- r point,to the mm bifurcation methods, and all were statistically significant, except for thickness (P .077). Bland-Altman plots showed a tendency toward a Distancepoint, from mm the 5.38 ± 1.446 5.46 ± 1.266 0.877 <.001 tion point, distance from the tibial insertion of the ALL to reduction of ALL thickness and width by MRI compared with anatomic¼ dissection. the lateral tibial plateau cartilage, total length of the ALL Distanceinsertion from to the the 5.38 ± 1.446 5.46 ± 1.266 0.877 <.001 Conclusion: MRI scanning as described can accurately assess the ALL and demonstrates characteristics similar to those seen (measured as the distance between its origin and tibial tibialinsertion plateau, to the mm under anatomic dissection. insertion), and thickness and width of the ALL—the same Length,tibial mm plateau, mm 36.62 ± 4.053 36.15 ± 3.76 0.943 <.001 measurements that had been performed on the MRI scans. Clinical Relevance: MRI can accurately characterize the ALL in the anterolateral region of the knee, despite the presence of Thickness,Length, mm mm 2.2336.62± 0.439± 4.053 1.54 36.15± 0.519± 3.76 0.507 0.943 .077 <.001 structures that might overlap and thus cause confusion when making assessments based on imaging methods. Width,Thickness, mm mm6.08 2.23± 1.038± 0.439 5.23 1.54± 0.725± 0.519 0.875 0.507 <.001 .077 Measurements were performed with approximately 15 of knee flexion and neutral rotation, similar to the knee posi- Keywords: anterolateral ligament; magnetic resonance imaging; MRI; anatomy Width, mm 6.08 ± 1.038 5.23 ± 0.725 0.875 <.001 ar, Spearman correlation coefficient; LCL, lateral collateral tion in the MRI studies. The width and thickness measure- ligament;ar, Spearman MRI, magnetic correlation resonance coefficient; imaging. LCL, lateral collateral ments were performed above the level of the lateral Recent anatomic studies have clearly established the head and Gerdy tubercle.8,11,17 Some authors also found ligament; MRI, magnetic resonance imaging. meniscus, similar to the measurements performed using landmarks for locating the origin and insertion of the knee an attachment to the lateral meniscus.9 The ALL has Figure 4. Anatomic photograph of a cadaveric left knee from MRI. Anatomic measurements were performed by 2 authors anterolateral ligament (ALL), as well as its path and char- recently been praised for its possible role as a stabilizer of Figure 3. Sagittal1,4,6,10,15,24,28 proton density–weighted section of the right Figurea lateral 4. viewAnatomic showing photograph the origin of of a the cadaveric anterolateral left knee ligament from independently (C.P.H., M.B.B.). Interobserver correlation of acteristics. According to the literature, the knee rotation, according to biomechanical studies per- RESULTS kneeorigin showing of the the ALL relationship is close to the between center the of the anterolateral lateral epicon- liga- a(ALL) lateralformed (1) view located by Monaco showing close et al theto20-22 the originand origin clinical of of the the studies anterolateral lateral that collateral have ligament liga- measurements was calculated. RESULTS mentdyle, (ALL) between and the the lateral origin collateral of the lateral ligament collateral (LCL). The ligament origins (ALL)mentadded (1) (LCL) located lateral (4). procedures closeThe ALL to the travels to origin conventional in of an the anteroinferior lateral intra-articular collateral direction liga- The 2 sets of measurements (MRI and anatomic speci- of both are close to the lateral femoral epicondyle (LFE), but the 5,26,27 The ALL was clearly observed on macroscopic inspection (LCL) and the insertion of the popliteus muscle tendon menttowardanterior (LCL) the cruciate (4). tibia The and ligament ALL bifurcates travels (ACL) (asterisk) reconstructions.in an anteroinferior before its insertions direction mens) were subjected to statistical analysis using SPSS ALL(PMT) runs anteriorly or slightly to theproximal LCL and and inserts posterior in the to thelateral lateral tibial epi- pla- Despite the anatomic and biomechanical studies avail- (grossThe ALL anatomy) was clearly in all 13 observed dissected on knees. macroscopic The entire inspection path in the meniscus (2) and the tibia (3). GT, Gerdy tubercle; FH, teaucondyle. (LTP) while The the ALL insertion then goes of the in LCL an anteroinferior is in the fibular directionhead (FH). towardable, the few tibia studies and have bifurcates assessed (asterisk) the ALL usingbefore imaging its insertions of(gross the ALL anatomy) was also in all visualized 13 dissected in all knees. of the The MRI entire scans path fibular head. toward the tibia, having an insertion between the fibular in themethods, meniscus particularly (2) and magnetic the tibia resonance (3). GT, imaging Gerdy tubercle;(MRI), FH, (Figuresof the ALL 4 and was 5). Thealso anatomic visualized and in MRI all of measurements the MRI scans Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 fibularwhich head. is the standard method for assessment of knee liga- are(Figures provided 4 and in Table 5). The 2. anatomic and MRI measurements ments.1,2,12,14 Three recent studies investigated the ALL The Orthopaedic Journal of Sports Medicine, 3(12), 2325967115621024 areThe provided attachment in Table of the 2. ALL in the lateral epicondyle DOI: 10.1177/2325967115621024 using MRI, 2 of which examined individuals without a liga- region was found anterior and distal to the attachment of ª The Author(s) 2015 ment injury and the third examined individuals with an The attachment of the ALL in the lateral epicondyle theregion LCL. was The found ligament anterior then and coursed distal anterodistally to the attachment to the of proximal anterolateral tibial region, attaching between the This open-access article is published and distributed under the Creative Commons Attribution - NonCommercial - No Derivatives License (http://creativecommons.org/ the LCL. The ligament then coursed anterodistally to the licenses/by-nc-nd/3.0/), which permits the noncommercial use, distribution, and reproduction of the article in any medium, provided the original author and source are Gerdy tubercle and the fibular head 5.3 mm under the lat- credited. You may not alter, transform, or build upon this article without the permission of the Author(s). For reprints and permission queries, please visit SAGE’s Web site proximal anterolateral tibial region, attaching between the eral tibial plateau. Close proximity to the lateral meniscus at http://www.sagepub.com/journalsPermissions.nav. Gerdy tubercle and the fibular head 5.3 mm under the lat- was observed during its course. eral tibial plateau. Close proximity to the lateral meniscus 1 Through use of MRI, the ALL was characterized with Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 was observed during its course. greater clarity on the coronal and axial planes as a thin lin- earThrough structure usewith of a thickness MRI, the varying ALL was between characterized 1 and 2 mm with andgreater surrounded clarity byon adiposethe coronal tissue and or axial synovial planes fluid. as The a thin ori- lin- ginear of structure the ALL withon the a thicknessouter face varying of the lateral between femoral 1 and con- 2 mm dyleand was surrounded located immediately by adipose tissue anterior or synovial to the LCL. fluid. The ori- ginThe of ALL the ALLshowed on an the anteroinferior outer face of path, the lateral superficial femoral to the con- origindyle was of the located popliteal immediately tendon groove. anterior A bifurcation to the LCL. could be observedThe ALL above showed the lateral an anteroinferior inferior geniculate path, artery, superficial leading to the toorigin a meniscus of the and popliteal a tibial tendon insertion. groove. The tibial A bifurcation segment of could the be ALLobserved was inserted above the 5.4 lateral mm beneath inferior the geniculate plane of artery, the lateral leading Figure 5. Anatomic photograph of a cadaveric left knee from tibialto a meniscus plateau and and under a tibial the insertion. insertion The of the tibial iliotibial segment tract. of the an anterolateral view showing the origin (1) and tibial insertion ALLInterobserver was inserted correlation 5.4 mm beneath for anatomic the plane measurements of the lateral Figure(3) of the5. Anatomic knee anterolateral photograph ligament of a cadaveric (ALL). The left ALL knee is sur-from variedtibial betweenplateau and 0.86 under and 0.96. the insertionIntra- and of interobserver the iliotibial cor-tract. anrounded anterolateral by the view blue showing suture. The the lateral origin meniscus (1) and tibial is indicated insertion relationInterobserver for MRI measurements correlation for were anatomic 0.77 to 0.93 measurements and 0.85 (3)by of (2). the LCL, knee lateral anterolateral collateral ligament ligament; (ALL). LFC, The lateral ALL femoral is sur- tovaried 0.90, respectively.between 0.86 and 0.96. Intra- and interobserver cor- roundedcondyle. by the blue suture. The lateral meniscus is indicated relationWith regard for MRI to the measurements correlation between were 0.77 the anatomicto 0.93 and and 0.85 by (2). LCL, lateral collateral ligament; LFC, lateral femoral MRIto 0.90, findings, respectively. the correlation coefficient (r) was between 0 condyle.20.0 software (IBM Corp). The Spearman correlation andWith 1 for regard all studied to the variables, correlation denoting between that the the anatomic 2 values and coefficient (r)wascalculatedwiththecorresponding95% tendedMRI findings, to increase the or correlation decrease together. coefficient All values (r) was were between sta- 0 confidence interval (P <.05).Inaddition,acomparative tistically significant except for ALL thickness (P .077), 20.0 software (IBM Corp). The Spearman correlation and 1 for all studied variables, denoting that the¼ 2 values analysis of the correlation between the 2 sets of measure- which showed a minor correlation coefficient (r 0.507) coefficient (r)wascalculatedwiththecorresponding95% tended to increase or decrease together. All values¼ were sta- confidencements was interval performed (P using<.05).Inaddition,acomparative Bland-Altman plots. betweentistically methods. significant except for ALL thickness (P .077), ¼ analysis of the correlation between the 2 sets of measure- which showed a minor correlation coefficient (r 0.507) ¼ ments was performed using Bland-Altman plots. between methods. Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015

Downloaded from ojs.sagepub.com at MUSEU PAULISTA USP on December 23, 2015 Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-014-3117-z

KNEE

A cadaveric study of the anterolateral ligament: re-introducing the lateral capsular ligament

Knee Surg Sports Traumatol Arthrosc Scott Caterine • Robert Litchfield • Marjorie Johnson • Blaine Chronik • Alan Getgood

Received: 21 February 2014 / Accepted: 1 June 2014 Ó Springer-Verlag Berlin Heidelberg 2014

Abstract Results The ALL was found in all ten knees undergoing Purpose The purpose of this study was to verify and MRI and all nineteen knees undergoing anatomical dissec- characterize the anatomical properties of the anterolateral tion, with MRI being able to predict its corresponding ana- capsule, with the aim of establishing a more accurate tomical dissection. The ALL was found to have bone-to- anatomical description of the anterolateral ligament (ALL). bone attachment points from the lateral femoral epicondyle Furthermore, microscopic analysis of the tissue was per- to the lateral tibia, in addition to a prominent meniscal formed to determine whether the ALL can morphologically attachment. Histological sectioning showed ALL morphol- be classified as ligamentous tissue, as well as reveal any ogy to be characteristic of ligamentous tissue, having dense, potential functional characteristics. regularly organized collagenous bundles. Immunohisto- Methods Three different modalities were used to validate chemistry revealed a large network of peripheral nervous the existence of the ALL: magnetic resonance imagining innervation, indicating a potential proprioceptive role. (MRI), anatomical dissection, and histological analysis. Conclusion From this study, the ALL is an independent Ten fresh-frozen cadaveric knee specimens underwent structure in the anterolateral compartment of the knee and MRI, followed by anatomical dissection which allowed may serve a proprioceptive role in knee mechanics. comparison of MRI to gross anatomy. Nine additional fresh-frozen cadaveric knees (19 total) were dissected for a Keywords Anterolateral ligament (ALL) MRI Á Á further anatomical description. Four specimens underwent Histology Immunohistochemistry ACL Lateral Á Á Á H&E staining to look at morphological characteristics, and capsularFig. ligament 2 Two MRI scans of the ALL in different specimens with their anatomical variation 2. c Anatomical dissection corresponding with one specimen was analysed using immunohistochemistry corresponding anatomical dissections beneath them. a MRI scan with the anatomical variation seen in its corresponding MRI above, to locate peripheral nervous innervation. full visualization of the ALL only when completely anterior to the showing that the ALL originates completely anterior to the FCL, then FCL. The ALL is shown as a thin, dark band with difficulty continues distally to insert onto the lateral tibia. d Anatomical Introductionvisualizing the proximal attachment point. With the ALL completely dissection corresponding with the anatomical variation seen in its anterior to the FCL, this MRI is classified as anatomical variation 1. corresponding MRI above, showing that the ALL crosses proximally Electronic supplementary material The online version of this b MRI scan showing a crossing orientation between the proximal over the FCL and inserts posteriorly, then continues distally to insert article (doi:10.1007/s00167-014-3117-z) contains supplementary A thoroughfibres of theunderstanding ALL and FCL. This of anatomycrossing orientation continues showsto the formALL onto the lateral tibia. ALL anterolateral ligament, FCL fibular material, which is available to authorized users. the foundationinserts posterior–proximal upon which to the FCL, surgeons making this should MRI classified develop as collateral ligament, and Pop popliteus tendon treatments for pathological musculoskeletal conditions. In S. Caterine M. Johnson Á the pastIn 10 longitudinal years, the section, technique the body of anterior of the ALL cruciate is compa- liga- the lateral joint capsule (Fig. 3d). Both the ACL and ALL Department of Anatomy and Cell Biology, Schulich School of rable with that of the ACL (Fig. 3a). The ALL body shows show fascicular organization in cross section, with the ALL Medicine and Dentistry, Western University, 1151 Richmond St, ment (ACL) reconstruction has evolved due to a greater prominent parallel collagen bundles with a crimping pattern, having smaller collagenous bundles of various size. In London, ON N6A 3K7, Canada understandingand fibroblast of nucleiACL arranged insertional in rows anatomy indicative [13 of]. dense As a contrast, there is a clear distinction of the ALL in cross result, the term anatomical ACL reconstruction has become S. Caterine R. Litchfield A. Getgood (&) regular connective tissue (Fig. 3b). The collagen pattern of section compared with the joint capsule, as the joint cap- Fowler KennedyÁ Sport MedicineÁ Clinic, 3M Centre, Western commonplacethe ALL seemed to describe to be organizedcurrent surgical into individual techniques ‘bundles’, [11]. sule resembles a loose connective tissue. University, 1151 Richmond St, London, ON N6A 3K7, Canada However,indicating clinical that studiesthe structure demonstrate may be a combination that despite of mul-these Analysis of the FCL, ALL, and popliteus tendon inser- e-mail: [email protected] new ACLtiple reconstruction thickenings of the techniques, lateral joint surgical capsule treatment rather than still a tion on the lateral femoral epicondyle showed that all three fails tohomogenous reproducibility entity such control as the rotational ACL. Though instability this pattern com- attachment points had almost identical morphologies. B. Chronik paredwas with seen the most uninjured often, there wereknee. still These portions findings of the ALL have in Because all three attachment points can be easily distin- Department of Physics and Astronomy, Western University, which a consistent collagenous pattern was observed; spe- guished from each other, it provides evidence that the ALL 1151 Richmond St, London, ON N6A 3K7, Canada promptedcifically, researchers near the and femoral clinicians and tibial to look attachment for alternative points, origin is anatomically distinct compared with the sur- which had a very dense, homogenous morphology. rounding FCL or popliteal origin. Similar to the femoral In cross section, the ALL is again comparable with the insertion of the FCL (Fig. 3e), the ALL’s femoral attach- ACL (Fig. 3c), though it greatly differs in comparison123 with ment shows a transition from ligamentous tissue to

123 • Have we ever injured the ALL? • Have we ever injured the ALL?

Prevalence and Classification of Injuries of Anterolateral Complex in Acute Anterior Cruciate Ligament Tears

Andrea Ferretti, M.D.,PREVALENCE Edoardo OF Monaco, INJURIES M.D., OF ANTEROLATERAL Mattia Fabbri, COMPLEX M.D., Barbara Maestri, M.D., 5 and Angelo De Carli, M.D. lateral capsular ligaments showing how anterolateral instability origin could reflect not only an ACL lesion.35-39 As a matter of fact, isolated ACL transec- tion almost never produces a pivot shift greater than Purpose: To report on the prevalence of injuries of the lateral compartment40 occurring in cases of apparently isolated acute anterior cruciate ligament (ACL) tears and to present a90% anterolateral complex grade classification 1, suggesting system of anterolateral that while complex in “glide injuries pivot based” ACL on the data obtained. Methods: Sixty patients operated on forrupture an acute could apparently more isolated often be ACL isolated, tear, revealed in grade by clinical 2 or 3 of examination and confirmed by magnetic resonance imaging,abnormalies pivot were prospectively shift an involvement selected. The lateral of secondary compartment restrains was exposed and injuries were detected. Based on the data obtained,should lesions be considered. of the anterolateral41 In their complex in vitro were study, classifi Monacoed as follows: Type I: multilevel rupture with individual layers tornet at al. different42 found levels no with signi macroscopicficant rotational hemorrhage instability involving after the area of the anterolateral ligament (ALL) and extended to the anterolateral capsule. Type II: multilevel rupture with individual layers torn at different levels with macroscopic hemorrhagecutting the extended ACL, from until the the area transection of the ALL and of capsule the lateral to the posterolateral capsule. Type III: complete transverse tear involvingcapsular the ligament area of the was ALL performed, near its insertion suggesting to the alateral deter- tibial plateau, distal to the lateral meniscus. Type IV: bony avulsionmining (Segond role of fracture). secondary The pivot-shift restraint test injuries was repeated in con- intraoperatively after repair of lateral tears before the ACL reconstruction.junction withResults: an ACLAlthough rupture. magnetic Given the resonance importance im- aging was able to detect only bony injuries (Segond fracture),of ligaments macroscopic of the tears lateral of the compartment lateral capsule werein the clearly patho- identified at surgery in 54 of 60 patients and classified as follows: Type I: 19/60 Type II: 16/60 Type III: 13/60 Type IV: 6/ Fig 4. 60The In lateral all cases, compartment repair resulted is exposed in a marked under reduction the iliotibial or apparentphysiology disappearance of the of the“ pivot-shiftanterolateral phenomenon.” pattern Statistical of knee tract: typeanalysis II lesion showed (black a positive arrow) correlation (right knee). between lesions of theinstability, lateral compartment, the investigation regardless of of the these type described, structures and could a pivot shift graded 2 or 3. Conclusions: Because injuries of secondarybecome important restraints often to occuroptimize in cases the of outcomes acute ACL oftears, ACL occurringrecognition along andwith repair the ofACL such tear lesions was could made be by considered Terry to helprepair. ACL reconstruction to better control rotational stability. et al.22Levelin a of series Evidence: of 82Level cases IV, of therapeutic acute ACL case injuries, series. In a recent anatomical and biomechanical study, where they found 93% of injuries of the lateral Kennedy et al.43 described the ALL as a 36.8- to compartment, including superficial and deep layer 41.6-mm-long ligament originating posterior and prox- tears bothistorically, transverse arthroscopic and interstitial. treatment They of concluded anterolateral imalresult to in the only femural fair control attachment of a pivot-shift of the lateral phenomenon collateral that theH severityinstabilities of the has pivot specifi shiftcally and focused Lachman on anterior test ligamentafter ACL and reconstruction. with a tibial Since attachment the report approximately of Segond,10 was relatedcruciate toligament a spectrum (ACL) reconstruction, of anatomic providing injuries good of midwaythese structures between have the been Gerdy clearly tubercle identi andfied as the effective anterior structuresto excellent other than results the in ACL. most cases.However, However, their a series persistent of marginrotational of the stabilizersfibular head.of the The knee. pull-out11-13 Recent test revealed studies a patientsinstability included of thecases knee of multiligamentousat follow-up, especially injuries, under meanhave strength further investigated of 175 N and the a mean anatomy stiffness of the of so-called 20 N/mm, leadingrotatory to possible load as bias revealed in the by results. a positive Moreover, pivot-shift some test, is with“anterolateral failure occurring ligament, by” ligamentousadvocating an tear important at the femoral role otherreported studies have in 11% investigated to 30% patients the importance by many authors. of the1-9 (4/15of this cases) structure or tibial in (1/15controlling cases) internal origin, rotationby midsubstance of the Some authors have focused on the ligaments of the knee.14-18 According to previous biomechanical studies, lateral aspect of the knee acting as secondary restraints it is now well recognized that high-grade pivot shift of the ACL-deficient knee, whose deficiency could after the ACL tear is also related to injury or relaxation of the secondary restraints (ALL and capsule, LCL, lateral meniscus).19 These injuries can occur at the time From the II School of Medicine, Sant’Andrea Hospital, Kirk Kilgour Sports of the ACL tear in acute cases and/or as a result of Injury Center, University of Rome “La Sapienza,” Rome, Italy. overloading or subsequent giving-way episodes in The authors report the following potential conflict of interest or source of funding: A.F., E.M., and A.D.C. receive support from Arthrex. chronic cases. Despite several detailed descriptions of Received December 16, 2015; accepted May 4, 2016. anatomy of the lateral compartment, there are very few Address correspondence to Mattia Fabbri, M.D., II School of Medicine, reports about injuries of these structures occurring in ’ 12,13,20-22 Fig 5. Sant(A)Andrea TypeHospital, III lesion: Kirk com- Kilgour Sports Injury Center, University of Rome acute ACL tears. Moreover, although lesions “La Sapienza”, Via Ferdinando Galiani 50, 00191 Rome, Italy. E-mail: of the medial compartment have been accurately plete [email protected] tear involving described by Müller in 1972,23 a lack of classification the area ofÓ 2016 ALL by near the Arthroscopy its insertion Association of North America to the lateral0749-8063/151167/$36.00 tibial plateau, al- and description of the lesions of the lateral compart- ways distalhttp://dx.doi.org/10.1016/j.arthro.2016.05.010 to lateral meniscus. ment, especially of the deep layer, still exists. (B) Type IV lesion: bony avulsion (Segond fracture [SF]). (ALL, anterolateral ligament;Arthroscopy: GT, The Journal of Arthroscopic and Related Surgery, Vol -, No - (Month), 2016: pp 1-8 1 Gerdy tubercle; LCL, lateral collateral ligament.) Assessment of the Anterolateral Ligament of the Knee by Magnetic Resonance Imaging in Acute Injuries of the Anterior Cruciate Ligament Camilo Partezani Helito, M.D., Paulo Victor Partezani Helito, M.D., Hugo Pereira Costa, M.D., Marco Kawamura Demange, M.D., Ph.D., and Marcelo Bordalo-Rodrigues, M.D., Ph.D. 6 C. P. HELITO ET AL.

ASSESSMENT OF THE ALL OF THE KNEE BY MRI 3 lesions without associated Segond fracture are classified Purpose: To evaluate the epidemiology of injuries and abnormalities of the anterolateral ligament (ALL) by magnetic resonance imaging (MRI) in cases of acute anterior cruciate ligament (ACL) injury. Methods: MRIs of patients with acute as “Segond-like” injuries in which anterolateral insta- ACL injury were evaluated. Acute injuries of the ACL were considered in cases in which the patient reported knee trauma bility associated with the ACL injury can occur. occurring less than 3 weeks prior and when bone bruise in the femoral condyles and tibial plateau was identified. ALL abnormality was considered when it showed proximal or distal bone detachment, discontinuity of fibers, or irregular The meniscal insertion of the ALL showed abnormal- contour associated with periligamentous edema. The ALL was divided into femoral, tibial, and meniscal portions, and the ities in almost half of the cases. This insertion has been lesions and/or abnormalities of each portion were characterized. The correlation of ALL injury with injuries of the lateral meniscus was evaluated. Results: A total of 101 MRIs were initially evaluated. The ALL was not characterized in 13 cited in several anatomical studies and recently charac- (12.8%) examinations, resulting in 88 (87.1%) cases of injury evaluation. Of these, 55 (54.4%) patients had a normal 2-4,7 3 ALL, and 33 (32.6%) showed signs of injury. Among the cases with injury, 24 (72%) patients showed proximal lesions, 7 terized in detail. Helito et al. presented a histological (21%) showed distal lesions, and 2 (6.0%) patients presented both proximal and distal lesions. The meniscal portion of the analysis of this insertion showing true ligament tissue ALL appeared abnormal in 16 (48%) patients. No relationship was found between ALL injury and lateral meniscus injury. Conclusions: Based on MRI analysis of acute ACL injuries with bone bruising of the lateral femoral condyle and lateral reaching the capsular portion of the lateral meniscus. tibial plateau, approximately a third demonstrated ALL injuries of which the majority was proximal. Level of Caterine et al.4 suggested that ALL traction could move Evidence: Level IV, case series. the lateral meniscus so that an eventual ALL traction

Fig 1. Schematic drawing showing with anterolateral movement of the tibia could cause the anterolateral ligament and the injury patterns (femoral lesion athe anterolateral ligament (ALL) of the knee, Detailed anatomical studies showed that the origin of injury of the lateral meniscus. In the present study, we the top, tibial lesion in the middle,although described for more than 100 years, began the ALL is adjacent to the lateral epicondyle, and it has and Segond fracture at the botton).T found injury of the lateral meniscus associated with the receiving attention only in recent years because of its 2 insertions, a tibial insertion, just below the lateral possible role in the genesis of the anterolateral stability plateau, and a meniscal insertion, between the anterior ACL in 21.7% of the cases, most of them in the meniscal of the knee, especially in cases of anterior cruciate lig- horn and the body of the lateral meniscus.4-9 body, which is the insertion site of the ALL. We found no ament (ACL) injury that do not progress satisfactorily Studies to characterize the ALL by magnetic resonance after surgery.1-3 imaging (MRI) were also performed.4-6 Caterine et al.4 statistical association between injuries of the ALL and the performed studies using cadavers, and Helito et al.5 and lateral meniscus, and thus, it is possible that when injury Porrino et al.6 studied the ALL in living individuals. All of of the ALL occurs, the meniscus remains intact and when From the Hospital Sírio-Libanês (C.P.H., P.V.P.H., H.P.C., M.B-R.); these studies were performed in individuals without ACL Knee Surgery Division (C.P.H., M.K.D.) and Musculoskeletal Radiology injury to characterize normal ALL anatomy. Even on the ALL is intact, the energy dissipates in the meniscus Department (P.V.P.H., H.P.C., M.B-R.), Faculty of Medicine, Institute of knees considered normal, Helito et al.5 characterized the Orthopedics and Traumatology, University of São Paulo, São Paulo, entire path of the ALL in only 71.7% of subjects. causing injury. Thus, the combined damage of these 2 Brazil. Asingleretrospectivestudyintheliterature,conducted The authors report that they have no conflicts of interest in the authorship structures could only occur in higher energy traumas. by Claes et al.,10 characterized abnormalities in the ALL in and publication of this article. The epidemiological characterization of the ALL Work performed at Hospital Sírio-Libanês, São Paulo, Brazil. individuals with ACL injury before they underwent sur- Helito et al. 2017 Received November 24, 2015; accepted May 3, 2016. gical treatment and did not differentiate between acute, injury site may be important in the surgical indication Address correspondence to Camilo Partezani Helito, M.D., R. Prof. subacute, and chronic injuries. This study analyzed only of a possible procedure for repair or reconstruction of Daher Cutait, 69 - Bela Vista, São Paulo - SP, Brazil, 01308-060. E-mail: the proximal and distal portions of the ALL and did not [email protected] Fig 6. Magnetic resonance coronal T2W image with fat evaluate injuries of the meniscus portion and the associated this structure. Ligament injury with avulsion or bone Ó 2016 by the Arthroscopy Association of North America saturation depicts a normal Segond fracture. Note that the injury according to the0749-8063/151073/$36.00 criteria used in the present were considered abnormal on examination.injuries None of the of lateral meniscus. Moreover, because the type detachment may possibly be repaired, whereas injuries study. http://dx.doi.org/10.1016/j.arthro.2016.05.009the cases of proximal lesions showedof avulsion apparatus bone usedanterolateral was not identified, ligament the reproduction (ALL) of tibial portion is normally Among the cases with ALL abnormalities (33 cases), fragments in the femoral origin. Regarding the meniscal in its substance usually evolve better in the long-term injury of the femoral portion was present in 24 (72%) portion of the ALL, abnormalities were observed in 16 attached to the bone fragment. Segond fracture (arrow), bone cases (Fig 4), and injury of the tibial portion was present (48%) of the cases studied. with reconstruction. in 7 (21%) cases; the distal lesions were dividedArthroscopy: into 4 TheAmong Journal the ofcases Arthroscopic of acute andACL Related injury Surgery,(101 cases), Vol - 79, Nofragment- (Month), 2016: (arrow pp 1-7 head), and1 ALL tibial portion (curved (12%) cases of ligament injury (Fig 5) and 3 (9%) cases (78.2%) cases had no injury in the lateral meniscus, and Because MRI is not always accurate to detect an ALL of Segond fracture (Fig 6). In 2 cases (6%), both the 22 (21.7%) had abnormalities. Among the meniscal in- arrow). femoral portion and the tibial portion of the ligament juries (22 cases), 13 (59%) were in the meniscal body. lesion, alternative methods of imaging must be studied to search for this structure lesion. Ultrasound has et al.18 indicated the need for extra-articular re- already been studied to detect the ALL in normal knees inforcements in ACL reconstructions in cases of chronic with accuracy to detect the ligament in its whole path injury. The loosening of the ALL could be a reason for from the femur to the tibia.21 Its accuracy to detect ALL this tendency. lesions, however, has not been proven, but it can be an Another difference found in the present study in alternative method in cases when the MRI cannot ac- relation to the study of Claes et al.19 is the location of cess the ALL properly. the ALL abnormalities. Whereas in the present study the most of the patients exhibited proximal injury, Limitations Claes et al. found most injuries in the tibial portion. The main limitation of our study is the absence of a gold Both of these studies found a low percentage of Segond standard for the characterization and comparison of in- fractures; thus, these fractures cannot be the only juries to the ALL suggested by MRI. Although MRI is a indication of ALL injury or associated anterolateral method with great potential, the injury criteria were instability. Claes et al.19 suggested that Segond fractures established arbitrarily based on the experience of the are always related to a bone avulsion of the ALL; authors and on previous studies that evaluated this however, De Maeseneer et al.11 found that the iliotibial structure.4-11,19 In addition, no correlation between the band may also be involved in the genesis of this avul- lesions in the imaging examinations and the clinical sion. Davis et al.20 identified 2 cases of injury of the findings was performed, although notably, biomechan- knee lateral complex, comprising the ALL and lateral ical studies have shown the role of the ALL in the genesis collateral ligament. In the cases evaluated by Davis of anterolateral instability of the knee.22 The lack of as- et al., although no concomitant ACL injury was present, sociation between the ALL and the lateral meniscus le- the injuries were proximal. These differences in loca- sions might be suffering from a type 2 (or beta type) error tion between our study, the study of Claes et al.,10 and due to the sample size used and this should also be the cases evaluated by Davis et al.20 may be related to considered as a limitation of this study. The fact that we the trauma mechanism of ACL and ALL injuries. ALL evaluated the meniscus lesions by MRI and not by the • 113 MRIs were inially evaluated • ALL not characterized in 13 (12.8%) • 33 (37.5%) showed signs of injury • Only 3 Segond fractures Figure Click here to download Figure FIGURE 1.tif

Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-017-4498-6

KNEE

Anterolateral ligament abnormalities are associated Figure with peripheral ligament and osseous injuries in acute ruptures Click here to download Figure FIGURE 4.tiff of the anterior cruciate ligament

Camilo Partezani Helito1,2 · Paulo Victor Partezani Helito1,3 · Renata Vidal Leão1 · Marco Kawamura Demange2 · Marcelo Bordalo-Rodrigues1,3

Received: 7 November 2016 / Accepted: 27 February 2017 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017

Abstract anterolateral capsule and osseous contusions of the femoral Purpose Few studies have used MRI to identify the ALL. condyle and tibial plateau. No correlation was found with As it was shown that it is not possible to precisely char- medial meniscus, lateral meniscus and posterior cruciate acterize this ligament in all examination, it is important ligament injuries. There was no association between ALL to identify concomitant lesions that can help in diagnos- injuries and gender, and older patients were more likely to ing ALL abnormalities. It is important to characterise this present an ALL injury. injury due to its association with anterolateral knee insta- Conclusion ALL injuries are present in approximately bility. Thus, the present study was performed to determine 40% of ACL injuries, and a minority of these are Segond the frequency of ALL injuries in patients with acute ACL fractures. These injuries are associated with peripheral liga- rupture and to analyse its associated knee lesions. ment injuries, anterolateral structures lesions and bone con- Methods Patients with acute ACL injuries were evaluated tusions, but there is no association with meniscal injuries. by MRI. Among this population, the ALL was classified as Surgeons must be aware of these associations to consider non-visualised, injured or normal. The possible abnormali- an ALL lesion even if it is not completely clear in imaging ties of the meniscus, collateral ligaments, popliteus tendon, evaluation, especially if a high degree of anterolateral insta- posterior cruciate ligament, Iliotibial band (ITB), anterolat- bility is present on physical examination. eral capsule and osseus injuries were evaluated. The asso- Level of evidence III. ciation of an ALL injury with these other knee structures as well as sex and age was calculated. Keywords Anterolateral ligament · MRI · Anterior Results Among the 228 knees evaluated, the ALL could cruciate ligament · Diagnosis · Collateral ligaments · not be entirely identified in 61 (26.7%). Of the remaining Meniscus · Osseous contusions · Anterolateral capsule · 167, 66 (39.5%) presented an ALL abnormality and only Iliotibial band four (6.1%) were Segond fractures. ALL abnormalities were associated with lesions of the lateral collateral liga- Abbreviations ment, medial collateral ligament, popliteus tendon, ITB, ACL Anterior cruciate ligament ALL Anterolateral ligament MCL Medial collateral ligament * Camilo Partezani Helito LCL Lateral collateral ligament [email protected] PCL Posterior cruciate ligament Helito et al. 2017 PT Popliteus tendo 1 Hospital Sírio-Libanês, São Paulo, Brazil 2 MRI Magnetic resonance imaging Knee Surgery Division, Faculty of Medicine, Institute ITB Iliotibial band of Orthopedics and Traumatology, University of São Paulo, São Paulo, Brazil 3 Musculoskeletal Radiology Department, Faculty of Medicine, Institute of Orthopedics and Traumatology, University of São Paulo, São Paulo, Brazil

Vol.:(0123456789)1 3 Figure Click here to download Figure FIGURE 1.tif

Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-017-4498-6

KNEE

Anterolateral ligament abnormalities are associated Figure with peripheral ligament and osseous injuries in acute ruptures Click here to download Figure FIGURE 4.tiff of the anterior cruciate ligament

Camilo Partezani Helito1,2 · Paulo Victor Partezani Helito1,3 · Renata Vidal Leão1 · Marco Kawamura Demange2 · Marcelo Bordalo-Rodrigues1,3

Received: 7 November 2016 / Accepted: 27 February 2017 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017

Abstract anterolateral capsule and osseous contusions of the femoral Purpose Few studies have used MRI to identify the ALL. condyle and tibial plateau. No correlation was found with As it was shown that it is not possible to precisely char- medial meniscus, lateral meniscus and posterior cruciate acterize this ligament in all examination, it is important ligament injuries. There was no association between ALL to identify concomitant lesions that can help in diagnos- injuries and gender, and older patients were more likely to ing ALL abnormalities. It is important to characterise this present an ALL injury. injury due to its association with anterolateral knee insta- Conclusion ALL injuries are present in approximately bility. Thus, the present study was performed to determine 40% of ACL injuries, and a minority of these are Segond the frequency of ALL injuries in patients with acute ACL fractures. These injuries are associated with peripheral liga- rupture and to analyse its associated knee lesions. ment injuries, anterolateral structures lesions and bone con- Methods Patients with acute ACL injuries were evaluated tusions, but there is no association with meniscal injuries. by MRI. Among this population, the ALL was classified as Surgeons must be aware of these associations to consider non-visualised, injured or normal. The possible abnormali- an ALL lesion even if it is not completely clear in imaging ties of the meniscus, collateral ligaments, popliteus tendon, evaluation, especially if a high degree of anterolateral insta- posterior cruciate ligament, Iliotibial band (ITB), anterolat- bility is present on physical examination. eral capsule and osseus injuries were evaluated. The asso- Level of evidence III. ciation of an ALL injury with these other knee structures as well as sex and age was calculated. Keywords Anterolateral ligament · MRI · Anterior Results Among the 228 knees evaluated, the ALL could cruciate ligament · Diagnosis · Collateral ligaments · not be entirely identified in 61 (26.7%). Of the remaining Meniscus · Osseous contusions · Anterolateral capsule · 167, 66 (39.5%) presented an ALL abnormality and only Iliotibial band four (6.1%) were Segond fractures. ALL abnormalities were associated with lesions of the lateral collateral liga- Abbreviations ment, medial collateral ligament, popliteus tendon, ITB, ACL Anterior cruciate ligament ALL Anterolateral ligament MCL Medial collateral ligament * Camilo Partezani Helito LCL Lateral collateral ligament [email protected] PCL Posterior cruciate ligament Helito et al. 2017 PT Popliteus tendo 1 Hospital Sírio-Libanês, São Paulo, Brazil 2 MRI Magnetic resonance imaging Knee Surgery Division, Faculty of Medicine, Institute ITB Iliotibial band of Orthopedics and Traumatology, University of São Paulo, São Paulo, Brazil 3 Musculoskeletal Radiology Department, Faculty of Medicine, Institute of Orthopedics and Traumatology, University of São Paulo, São Paulo, Brazil

Vol.:(0123456789)1 3 Knee Surg Sports Traumatol Arthrosc

Fig. 2 Sagittal T2 FS-weighted MRI image (a) showing com- plete rupture of the anterior cruciate ligament (white arrow), with discontinuity and diffuse oedema, and Coronal T2 FS- Knee Surg Sports Traumatol Arthrosc weighted images showing injury DOI 10.1007/s00167-017-4498-6 of the medial collateral ligament (arrowheads) (b) and a normal KNEE anterolateral ligament (arrow- heads) (c)

Anterolateral ligament abnormalities are associated with peripheral ligament and osseous injuries in acute ruptures of the anterior cruciate ligament

Camilo Partezani Helito1,2 · Paulo Victor Partezani Helito1,3 · Renata Vidal Leão1 · Marco Kawamura Demange2 · Marcelo Bordalo-Rodrigues1,3 Table 2 Absolute number and percentage of associated knee injuries in cases of acute ACL injury

Received:• 7 NovemberALL lesion associated with: 2016 / Accepted: 27 February 2017 Number of Percentage (%) © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017 cases • Lateral collateral ligament Abstract anterolateral capsule and osseous contusions of the femoral Bone contusion 150 89.8 Purpose Few studies have used MRI to identify the ALL. condyle and tibial plateau. No correlation was found with ITB injury 101 60.5 As it• was shownMedial collateral ligament that it is not possible to precisely char- medial meniscus, lateral meniscus and posterior cruciate MCL injury 71 42.5 acterize this ligament in all examination, it is important ligament injuries. There was no association between ALL to identify concomitant lesions that can help in diagnos- injuries and gender, and older patients were more likely to Medial meniscus injury 70 41.9 ing ALL• abnormalities.Popliteus tendon It is important to characterise this present an ALL injury. ALL injury 66 39.5 injury due to its association with anterolateral knee insta- Conclusion ALL injuries are present in approximately Anterolateral capsule injury 50 29.9 bility. Thus, the present study was performed to determine 40% of ACL injuries, and a minority of these are Segond • Iliobial band LCL injury 50 29.9 the frequency of ALL injuries in patients with acute ACL fractures. These injuries are associated with peripheral liga- rupture and to analyse its associated knee lesions. ment injuries, anterolateral structures lesions and bone con- PT injury 35 20.9 Methods• PatientsAnterolateral capsule with acute ACL injuries were evaluated tusions, but there is no association with meniscal injuries. Lateral meniscus injury 30 18 by MRI. Among this population, the ALL was classified as Surgeons must be aware of these associations to consider PCL injury 6 3.6 non-visualised, injured or normal. The possible abnormali- an ALL lesion even if it is not completely clear in imaging ties of• the meniscus,Osseous contusions of the femoral collateral ligaments, popliteus tendon, evaluation, especially if a high degree of anterolateral insta- posterior cruciate ligament, Iliotibial band (ITB), anterolat- bility is present on physical examination. eral capsule andcondyle and osseus injuries were evaluated.bial The asso plateau. - Level of evidence III. ciation of an ALL injury with these other knee structures as injuries and injuries to the medial meniscus (p = n.s.), lat- well as sex and age was calculated. Keywords Anterolateral ligament · MRI · Anterior eral meniscus (p = n.s.) or PCL (p = n.s.). Injury to the ALL Results Among the 228 knees evaluated, the ALL could cruciate ligament · Diagnosis · Collateral ligaments · p not be entirely identified in 61 (26.7%). Of the remaining Meniscus · Osseous contusions · Anterolateral capsule · was not associated with gender ( = n.s.), but was associ- 167, • 66 (39.5%)No correlaon was found with: presented an ALL abnormality and only Iliotibial band ated with patient age, with older patients having a greater four (6.1%) were Segond fractures. ALL abnormalities Fig. 3 Sagittal T2 FS-weighted MRI image showing a complete rup- tendency to present with ALL injury associated with ACL were associated with lesions of the lateral collateral liga- Abbreviations ture of the proximal ACL (white arrow) (a) and Coronal T2 FS- (b) injury (p = 0.038). Partial ACL injuries were not associated ment,• medial collateralmedial meniscus, lateral meniscus ligament, popliteus tendon, ITB, ACL Anterior cruciate ligament and COR DP-weighted (c) MRI images showing a bone avulsion ALL Anterolateral ligament with ALL injury, but complete injuries were associated from the external margin of the lateral tibial plateau (Segond fracture) p and posterior cruciate ligament MCL Medial collateral ligament (arrow) and the anterolateral ligament attached to it (arrowheads). ( = 0.023). * Camilo Partezani Helito LCL Lateral collateral ligament The same patient antero-posterior knee radiograph shows the bone The interobserver correlation according to the kappa test [email protected] PCL Posterior cruciate ligament injuries. fragment from the external margin of the lateral tibial plateauHelito et al. 2017 (d) was 0.724. The intraobserver correlations were 0.819 and 1 PT Popliteus tendo Hospital Sírio-Libanês, São Paulo, Brazil 0.855 for the two evaluators. Both results were considered 2 MRI Magnetic resonance imaging Knee Surgery Division, Faculty of Medicine, Institute ITB Iliotibial band of Orthopedics and Traumatology, University of São Paulo, satisfactory. São Paulo, Brazil an increased correlation with the degree of the ITB abnor- The medical records of 68 patients with a described 3 Musculoskeletal Radiology Department, Faculty mality (no injury < low-grade injury < high-grade injury) ALL injury on MRI were available for evaluation. Among of Medicine, Institute of Orthopedics and Traumatology, University of São Paulo, São Paulo, Brazil (p = 0.000021). No cases of complete ITB injury were these patients, 34 presented a grade 1 pivot, 24 a grade 2 observed (Figs. 5, 6) (Table 3). There was also an increased pivot and 10 a grade 3 pivot. ALL abnormalities were Vol.:(0123456789)correlation1 3 with bone contusions in the tibial plateau and present in 3 (8.8%) patients with grade 1 pivot, 12 (50%) femoral condyle related to ALL injury (without injury patients with grade 2 pivot and 8 (80%) patients with grade <, femoral condyle only <, tibial plateau only < both) 3 pivot. A correlation between high-grade pivot shift and (p = 0.008) (Fig. 7). There was no correlation between ALL an ALL MRI abnormality was found (p = 0.000018).

1 3 ALL not % of ALL Author ACL tear type characterized abnormalities

Claes Acute, sub acute, Acta Orthop Belg 2014 24% 78.7 chronic

Van Dyck Eur Radiol 2016 acute 20% 46%

Helito Arthroscopy 2017 acute 12.8% 37.5%

Helito acute 26.7% 39.5% KSSTA 2017 ALL not % of ALL Author ACL tear type characterized abnormalities

Claes Acute, sub acute, Acta Orthop Belg 2014 24% 78.7 chronic

Van Dyck Eur Radiol 2016 acute 20% 46%

Helito Arthroscopy 2017 acute 12.8% 37.5%

Helito acute 26.7% 39.5% KSSTA 2017 ALL not % of ALL Author ACL tear type characterized abnormalities

Claes Acute, sub Acta Orthop Belg 2014 24% 78.7 acute, chronic

Van Dyck Eur Radiol 2016 acute 20% 46%

Helito Arthroscopy 2017 acute 12.8% 37.5%

Helito acute 26.7% 39.5% KSSTA 2017 ASSESSMENT OF THE ALL OF THE KNEE BY MRI 5

In the study performed by Claes et al.,10 the ALL was not characterized in 24% of the evaluated knees, a percentage similar to that found by Helito et al.5 in knees of patients without injury and slightly higher than that found in the present study. The larger number of cases in which the ALL was observed in the present study can be attributed to factors including the greater ease of viewing in the presence of joint effusion due to acute ACL injury, the fact that some examinations were performed on a 3.0 T device, and the increasing expe- rience of the observers for the evaluation of this structure over time. In regard to the number of observed abnormalities and location of the ligament injuries, Claes et al.10 found injury in the majority of cases, whereas in the present study, around one-third of cases showed injury, with the most cases presenting an ALL with a normal Assessmentsignal and path. ofthe The possible Anterolateral reasons for this Ligament discrep- of the fi ancy included different criteria and experience of the Prevalence and Classi cation of Injuries of Anterolateral Kneeassessors by Magneticand the fact that Resonance Claes et al.10 evaluated Imaging cases in Acute Complex in Acute Anterior Cruciate Ligament Tears Injurieswith chronic of ACL the rupture Anterior in which Cruciate it is possible Ligament that untreated ACL injuries could force the ALL as a sec- Andrea Ferretti, M.D., Edoardo Monaco, M.D., Mattia Fabbri, M.D., Barbara Maestri, M.D., Camiloondary Partezani restrictor Helito, and cause M.D., injury Paulo ofVictor this Partezanistructure Helito,at a M.D., and Angelo De Carli, M.D. Hugolater Pereira stage. Costa,15,16 M.D.,Sonnery-Cottet Marco Kawamura et al.17 Demange,and Duthon M.D., Ph.D., and Marcelo Bordalo-Rodrigues, M.D., Ph.D. PREVALENCE OF INJURIES OF ANTEROLATERAL COMPLEX 5

Fig 4. Magnetic resonance coronal T2W image with fat Purpose: To report on the prevalence of injuries of the lateral compartment occurring in cases of apparently isolated saturation depicts an anterolateral ligament femoral portion acute anterior cruciate ligament (ACL) tears and to present a classification system of anterolateral complex injuries based lesion. There is a disruption at its origin, with redundancy of on the data obtained. Methods: Sixty patients operated on for an acute apparently isolated ACL tear, revealed by clinical lateral capsular ligaments showing how anterolateral Purpose: To evaluate the epidemiology of injuries and abnormalities of the anterolateral ligament (ALL) by magnetic fi the reminiscent fibers. Femoral portion (arrow), meniscal examination and con rmed by magnetic resonance imaging, were prospectively selected. The lateral compartment was fl resonance imaging (MRI) in cases of acute anterior cruciate ligament (ACL) injury. Methods: MRIs of patients withexposed acute and injuries were detected. Based on the data obtained, lesions of the anterolateral complex were classified as instability origin could re ect not only an ACL portion (arrow head), and tibial portion (curvedACL arrow). injury were evaluated. Acute injuries of the ACL were considered in cases in which the patient reported kneefollows: trauma Type I: multilevel rupture with individual layers torn at different levels with macroscopic hemorrhage involving 35-39 occurring less than 3 weeks prior and when bone bruise in the femoral condyles and tibial plateau was identified.theALL area of the anterolateral ligament (ALL) and extended to the anterolateral capsule. Type II: multilevel rupture with lesion. As a matter of fact, isolated ACL transec- abnormality was considered when it showed proximal or distal bone detachment, discontinuity of fibers, or irregularindividual layers torn at different levels with macroscopic hemorrhage extended from the area of the ALL and capsule to contour associated with periligamentous edema. The ALL was divided into femoral, tibial, and meniscal portions,the and posterolateral the capsule. Type III: complete transverse tear involving the area of the ALL near its insertion to the lateral tion almost never produces a pivot shift greater than collateral ligament, anterolateral capsule, andlesions iliotibial and/or abnormalities of each portion were characterized. The correlation of ALL injury with injuries of thetibial lateral plateau, distal to the lateral meniscus. Type IV: bony avulsion (Segond fracture). The pivot-shift test was repeated 40 band, which cause a partial volume effect inmeniscus the region, was evaluated. Results: A total of 101 MRIs were initially evaluated. The ALL was not characterizedintraoperatively in 13 after repair of lateral tears before the ACL reconstruction. Results: Although magnetic resonance im- grade 1, suggesting that while in “glide pivot” ACL hampering the identification of that structure.(12.8%) examinations, The resulting in 88 (87.1%) cases of injury evaluation. Of these, 55 (54.4%) patients had aaging normal was able to detect only bony injuries (Segond fracture), macroscopic tears of the lateral capsule were clearly ALL, and 33 (32.6%) showed signs of injury. Among the cases with injury, 24 (72%) patients showed proximal lesions,identifi 7ed at surgery in 54 of 60 patients and classified as follows: Type I: 19/60 Type II: 16/60 Type III: 13/60 Type IV: 6/ rupture could more often be isolated, in grade 2 or 3 of small ALL thickness and its anatomical variability(21%) showed also distal lesions, and 2 (6.0%) patients presented both proximal and distal lesions. The meniscal portion60 of In the all cases, repair resulted in a marked reduction or apparent disappearance of the pivot-shift phenomenon. Statistical 5,11,12 difficult the complete visualization. ALL appeared abnormal in 16 (48%) patients. No relationship was found between ALL injury and lateral meniscusanalysis injury. showed a positive correlation between lesions of the lateral compartment, regardless of the type described, and a pivot shift an involvement of secondary restrains Helito et al.5 performed a study in 39 patientsConclusions: andBased on MRI analysis of acute ACL injuries with bone bruising of the lateral femoral condyle andpivot lateral shift graded 2 or 3. Conclusions: Because injuries of secondary restraints often occur in cases of acute ACL tears, 41 fi tibial plateau, approximately a third demonstrated ALL injuries of which the majority was proximal. Levelrecognition of and repair of such lesions could be considered to help ACL reconstruction to better control rotational stability. should be considered. In their in vitro study, Monaco identi ed the ALL in its entirety in aroundEvidence: two-thirdsLevel IV, case series. Level of Evidence: Level IV, therapeutic case series. 42 of the MRI scans, but additional coronal proton et al. found no significant rotational instability after densityeweighted sequences without fat saturation 13 cutting the ACL, until the transection of the lateral were also used. Taneja et al., in a study of 70 patients,he anterolateral ligament (ALL) of the knee, Detailed anatomical studies showed that the originistorically, of arthroscopic treatment of anterolateral result in only fair control of a pivot-shift phenomenon were able to visualize the ALL in its entiretyT inalthough a very described for more than 100 years, began the ALL is adjacent to the lateral epicondyle, andH it hasinstabilities has specifically focused on anterior after ACL reconstruction. Since the report of Segond,10 capsular ligament was performed, suggesting a deter- low percentage of the MRI scans, observingreceiving some attention only in recent years because of its 2 insertions, a tibial insertion, just below thecruciate lateral ligament (ACL) reconstruction, providing good these structures have been clearly identified as effective possible role in the genesis of the anterolateral stability plateau, and a meniscal insertion, between the anteriorto excellent results in most cases. However, a persistent rotational stabilizers of the knee.11-13 Recent studies mining role of secondary restraint injuries in con- portion of the ligament in around half of the scans. 4-9 6 of the knee, especially in cases of anterior cruciate lig- horn and the body of the lateral meniscus. instability of the knee at follow-up, especially under have further investigated the anatomy of the so-called junction with an ACL rupture. Given the importance Porrino et al. examined MRI scans of 53 patientsament (ACL) and, injury that do not progress satisfactorily Studies to characterize the ALL by magnetic resonancerotatory load as revealed by a positive pivot-shift test, is “anterolateral ligament,” advocating an important role in contrast to other studies, were able to characterizeafter surgery.1-3 imaging (MRI) were also performed.4-6 Caterinereported et al.4 in 11% to 30% patients by many authors.1-9 of this structure in controlling internal rotation of the of ligaments of the lateral compartment in the patho- the ALL in its entirety in all of the MRI scans. Notably, performed studies using cadavers, and Helito et al.Some5 and authors have focused on the ligaments of the knee.14-18 According to previous biomechanical studies, Porrino et al.6 performed their tests on a 3.0 T device, Porrino et al.6 studied the ALL in living individuals.lateral All of aspectFig of the 4. kneeThe acting lateral as secondary compartment restraints it is now is exposed well recognized under that high-grade the iliotibial pivot shift physiology of the “anterolateral” pattern of knee 5 these studies were performed in individuals withoutof ACLthe ACL-deficient knee, whose deficiency could after the ACL tear is also related to injury or relaxation whereas Helito et al. used a 1.5 T device. EvenFrom the when Hospital Sírio-Libanês (C.P.H., P.V.P.H., H.P.C., M.B-R.); Knee Surgery Division (C.P.H., M.K.D.) and Musculoskeletal Radiology injury to characterize normal ALL anatomy. Even on tract: type II lesion (black arrow)of the secondary (right restraints knee). (ALL and capsule, LCL, instability, the investigation of these structures could MRI does not yet present the accuracy of the 19 using 3.0 T devices, it is not possible to characterizeDepartment (P.V.P.H., the H.P.C., M.B-R.), Faculty of Medicine, Institute of knees considered normal, Helito et al.5 characterized the lateral meniscus). These injuries can occur at the time From the II School of Medicine, Sant’Andrea Hospital, Kirk Kilgour Sports of the ACL tear in acute cases and/or as a result of become important to optimize the outcomes of ACL ALL in all of examinations. Future studies usingOrthopedics smaller and Traumatology,Fig 5. UniversityMagnetic of São resonance Paulo, São Paulo, coronalentire T2W path image of the ALL with in onlyfat 71.7% of subjects. Brazil. Injury Center, University of Rome “La Sapienza,” Rome, Italy. overloading or subsequent giving-way episodes in slice thickness, less spacing between images, volumetric Asingleretrospectivestudyintheliterature,conductedThe authors report the following potential conflict of interest or source of The authors report thatsaturation they have no con depictsflicts of interest a lesion in the authorship in both meniscal and tibial10 portions macroscopic evaluaon for these lesions occurring along with thechronic ACL cases. tear Despite was several made detailed by descriptions Terry of repair. sequences, and special sequences focused onand publication the ALL of this article. by Claes et al., characterized abnormalities in thefunding: ALL in A.F., E.M., and A.D.C. receive support from Arthrex. of the anterolateral ligament (ALL). A meniscal tear is asso- Received December 16, 2015;22 accepted May 4, 2016. anatomy of the lateral compartment, there are very few path should be conducted to enhance accuracyWork performed in the at Hospital Sírio-Libanês, São Paulo, Brazil. individuals with ACL injury before they underwent sur- et al. in a series of 82 cases of acute ACL injuries, In a recent anatomical and biomechanical study, Received November 24, 2015;ciated. accepted ALL May femoral 3, 2016. portion (arrow)gical and meniscal treatment tear and did(arrow not differentiate between acute,Address correspondence to Mattia Fabbri, M.D., II School of Medicine, reports about injuries of these structures occurring in 14 12,13,20-22 43 visualization of this structure. Address correspondencehead). to Camilo Partezani Helito, M.D., R. Prof. Sant’Andrea Hospital, Kirk Kilgour Sports Injury Center, University of Rome acute ACL tears. Moreover, although lesions subacute, and chronic injuries. This study analyzed“ only ” where they found 93% of injuries of the lateral Kennedy et al. described the ALL as a 36.8- to Daher Cutait, 69 - Bela Vista, São Paulo - SP, Brazil, 01308-060. E-mail: La Sapienza , Via Ferdinando Galiani 50, 00191 Rome, Italy. E-mail: of the medial compartment have been accurately the proximal and distal portions of the ALL [email protected] did not [email protected] described byfi Müller in 1972,23 a lack of classification evaluate injuries of the meniscus portion and the associatedÓ 2016 by thecompartment, Arthroscopy Association of North America including super cial and deep layer 41.6-mm-long ligament originating posterior and prox- Ó 2016 by the Arthroscopy Association of North America 0749-8063/151167/$36.00 and description of the lesions of the lateral compart- 0749-8063/151073/$36.00 injuries of the lateral meniscus. Moreover, because the type http://dx.doi.org/10.1016/j.arthro.2016.05.010 ment, especially of the deep layer, still exists. http://dx.doi.org/10.1016/j.arthro.2016.05.009 of apparatus used was not identified, the reproduction of tears both transverse and interstitial. They concluded imal to the femural attachment of the lateral collateral that the severity of the pivot shift and Lachman test ligament and with a tibial attachment approximately Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol -, No - (Month), 2016: pp 1-8 1 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol -, No - (Month), 2016: pp 1-7 1 was related to a spectrum of anatomic injuries of midway between the Gerdy tubercle and the anterior structures other than the ACL. However, their series of margin of the fibular head. The pull-out test revealed a patients included cases of multiligamentous injuries, mean strength of 175 N and a mean stiffness of 20 N/mm, leading to possible bias in the results. Moreover, some with failure occurring by ligamentous tear at the femoral other studies have investigated the importance of the (4/15 cases) or tibial (1/15 cases) origin, by midsubstance

Fig 5. (A) Type III lesion: com- plete transverse tear involving the area of ALL near its insertion to the lateral tibial plateau, al- ways distal to lateral meniscus. (B) Type IV lesion: bony avulsion (Segond fracture [SF]). (ALL, anterolateral ligament; GT, Gerdy tubercle; LCL, lateral collateral ligament.) Physical examinaon correlaon

• 65 paents • Only acute ACL injuries • No associated lesion, even meniscus

• Associaon between MRI ALL abnormality and grade III Pivot and Lachman

Helito et al, unpublished data Risk Factors Associated With Grade 3 Pivot Shift After Acute Anterior Cruciate Ligament Injuries

Guan-yang Song,* MD, Hui Zhang,* MD, Qian-qian Wang,y MD, Jin Zhang,* MD, Yue Li,* MD, and Hua Feng,*z MD Investigation performed at the Sports Medicine Service of Beijing Jishuitan Hospital, Beijing, China

Background: Recent literature has demonstrated that involvement in pivoting sports at the time of injury, increased posterior- inferiorKnee Surg tibial Sports slope Traumatol (PITS), Arthrosc anterolateral (2017) 25:1111–1116 capsular ligament (ALCL) disruptions, and combined lateral meniscal lesions all contribute toDOI a 10.1007/s00167-017-4492-z higher grade of pivot shift after acute anterior cruciate ligament (ACL) injuries.

Purpose:KNEE To identify risk factors associated with grade 3 pivot shift after acute ACL injuries. Study Design: Case-control study; Level of evidence, 3. Methods: A database of patients undergoing primary ACL reconstruction from 2009 to 2015 after acute ACL injuries was retro- spectivelyPatients reviewed. with Ahigh-grade total of 30 patients pivot-shift (30 knees) with phenomenon grade 3 pivot shift are were associated identified as the study group. Moreover, 30 patients (30 knees) with grade 1 and 30 patients (30 knees) with grade 2 pivot shift were randomly chosen as the 2 control groups. Allwith pivot-shift higher tests prevalence were performed of with anterolateral the patients under ligament anesthesia. Predictors injury of grade 3 pivot shift that were explored includedafter acute patient age,anterior sex, time cruciate from injury toligament surgery, pivoting injuries sports involvement at the time of injury, lateral PITS, medial PITS, ALCL disruptions, preoperative KT-1000 arthrometer side-to-side difference, and combined lateral or medial meniscal lesions. Comparisons were performed between the study group and the 2 control groups. Univariable and multivariable logistic Guan-yang Song1 · Hui Zhang1 · Guan Wu1 · Jin Zhang1 · Xin Liu1 · Zhe Xue1 · regressions were used to identify independent risk factors that were associated with grade 3 pivot shift. Yi Qian1 · Hua Feng1 Results: Univariable and multivariable logistic regressions between the study group and the 2 control groups showed that pivot- ing sports involvement at the time of injury (odds ratio1 [OR1; grade 3 vs grade 1 pivot shift with grade 1 = reference], 11.88; 95% CI, 1.94-149.91; OR2 [grade 3 vs grade 2 pivot shift with grade 2 = reference], 3.41; 95% CI, 1.92-22.60), abnormal degree of lateral PITS (OR1, 14.41; 95% CI, 1.69-174.78; OR2, 6.41; 95% CI, 1.48-47.70), ALCL disruptions (OR1, 8.28; 95% CI, 1.71- Received: 14 November 2016 / Accepted: 18 February 2017 / Published online: 27 February 2017 117.14; OR , 4.96; 95% CI, 1.07-28.75), and combined lateral meniscal lesions (OR , 27.56; 95% CI, 5.48-240.52; OR , 5.83; © European Society2 of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017 1 2 95% CI, 1.21-38.56) were independent risk factors of grade 3 pivot shift after acute ACL injuries. Conclusion: For acute ACL injuries, the best set of predictors of grade 3 pivot shift were pivoting sports involvement at the time of Abstract musculoskeletal radiologists reviewed the magnetic reso- injury, abnormal lateral PITS, ALCL disruptions, and combined lateral meniscal lesions. These results may provide additional infor- Purpose To compare the prevalence of concomitant ante- nance imaging (MRI) scans for the presence of concomi- mation for counseling patients on residual laxity and risks for graft rerupture after ACL reconstruction. rolateral ligament (ALL) injury between patients with high- tant ALL injury. The grade of an ALL injury was divided Keywords:grade (gradesgrade II and 3 pivot III) pivot-shift shift; acute and anterior those with cruciate low- ligamentinto grade injury; 0 (normal),risk factor grade I (sprain), grade II (partial grade (grades 0 and I) pivot-shift phenomenon after acute tear), and grade III (complete tear). The prevalence and the anterior cruciate ligament (ACL) injuries. grade of concomitant ALL injury were further compared Methods Sixty-eight patients with an acute ACL injury between the study group and the control group. Thewho pivot-shift showed high-grade test is the (grades most specific II and clinical III) pivot-shift assessment Results of Overall,patient underthe prevalence anesthesia. of 18,36 concomitantThe test ALL evaluates the com- pathologicphenomenon knee were joint enrolled rotational as laxity the study after group. complete They anterior injury in thebined study tibiofemoral group (94.1%, internal 64/68) rotation was significantly and anterior tibial trans- cruciatewere matched ligament in a (ACL)1:1 fashion injury to when another it is68 performed ACL-injured with thehigher thanlation that that in the occur control when group the ACL [60.3%, is injured, (41/68), and the pathologic control participants who showed low-grade (grades 0 P < 0.05]. motion Specifically, elicited there during were the 49 test patients is recorded (49/64, as grade 0 (nor-

andzAddress I) pivot-shift correspondence phenomenon to Hua during Feng, MD, the Sports same Medicine study Ser-76.6%) whomal), showed grade grade 1 (glide), II/III grade (partial/complete 2 (clunk), or tear)grade 3 (locked sub- vice,period. Beijing Patients Jishuitan were Hospital, matched No. by 31, age, Xin Jiesex, Kou and East time Street, from Xi ChengMRI evidenceluxation) of concomitant according ALL to the injury, International which was Knee also Documentation 9 District,injury toBeijing, surgery. China A (email: standardized [email protected]). pivot-shift test was per- significantlyCommittee higher than classification. that in the controlAgrade3pivotshifthasbeen group (12/41, *Sports Medicine Service, Beijing Jishuitan Hospital, Beijing, China. 34 formed under anesthesia for all the patients. Two blinded 29.3%). shown to correlate with poorer clinical outcomes as well yClinical Research and Evidence-Based Medicine Center, Beijing 17 Institute of Traumatology and Orthopaedics, Beijing Jishuitan Hospital,Conclusionsas earlierPatients progression with high-grade of knee pivot-shiftosteoarthritis. phe- Despite exten- Beijing, China. nomenon sive showed clinical higher and prevalence biomechanical of concomitant research ALL involving the pivot- * TheHua authorsFeng declared that they have no conflicts of interest in theinjury comparedshift mechanism, to those with there low-grade is still pivot-shift a paucity phe of knowledge- about authorship and publication of this contribution. [email protected] nomenon the after risk acute factors ACL responsible injuries. Careful for a grade assessment 3 pivot shift. Guan-yang Song It has been shown that in the laboratory setting, iso- The American Journal of Sports Medicine, Vol. 44, No. 2 and proper treatment of this concomitant injury should be [email protected] lated ACL transection almost never produces a pivot shift DOI: 10.1177/0363546515613069 considered especially in knees with high-grade pivot-shift greater than grade 2.22 Recent literature has demonstrated Ó 2015Hui TheZhang Author(s) phenomenon. [email protected] Level of evidence III. Guan Wu 362 [email protected] Keywords Anterolateral ligament injury · Magnetic Jin Zhang resonance imaging · High-grade pivot shift · Low-grade [email protected] pivot shift · Acute anterior cruciate ligament injury Xin Liu [email protected] Zhe Xue Introduction [email protected] Yi Qian Arthroscopic treatment of anterolateral instabilities of the [email protected] knee joint has specifically focused on anterior cruciate 1 Sports Medicine Service, Beijing Jishuitan Hospital, No. 31, ligament (ACL) reconstruction, providing good-to-excel- Xin Jie Kou East Street, Xi Cheng District, Beijing, China lent results in most cases. However, residual rotational

Vol.:(0123456789)1 3 Take home message

• The “normal” ALL can be characterized in MRI (PD sequences, Lateral inferior genicular vessels) • Correlaon between anatomy and MRI (thickness?) • 40%-80% of ALL abnormalies in ACL injuries • Associaon with peripheral ligament injuries, anterolateral structures lesions and bone contusions, but there is no associaon with meniscal injuries • Associaon between ALL injury and increased laxity on physical examinaon Thank you [email protected]