Posterolateral Corner of the Knee: Microsurgical Analysis of Anatomy and Morphometry

n Feature Article

Michael Osti, MD; Peter Tschann, MD; Karl Heinz Künzel, MD; Karl Peter Benedetto, MD

abstract Full article available online at Healio.com/Orthopedics. Search: 20130821-11

Reconstruction of the posterolateral corner (PLC) of the knee is essential to restore knee joint function. Controversy exists regarding a standardized nomenclature, the connective attachments and the relationships between them, and the frequency of occurrence among all structures of the PLC. Thirty human cadaveric knee specimens were investigated. The lateral collateral ligament, popliteus tendon, popliteofibular ligament, fabellofibular ligament, arcuate ligament, oblique popliteal ligament, posterior meniscofemoral ligament, and popliteal hiatus (including the popliteomeniscal ligaments) were studied. The length, diameter, variations, course, and morphology of these structures, as well as the position and dimension of the insertion, were measured and referenced the footprints to adjacent bony landmarks. Compared with existing studies, the lateral collateral ligament footprint was more proximal to the lateral femoral epicondyle (average, 3.6160.75 mm) and the popliteus tendon insertion was more distal and anterior to the lateral collateral ligament footprint (average, 5.6961.36 mm and 4.9761.73 mm, respectively). Only minor data have been published on the fabellofibular ligament (average length, 33.7964.98 mm; average diameter, 4.0461.22 mm), Figure: Dorsal photograph of the posterolateral arcuate ligament (average length, 31.5462.82 mm; average diameter, 7.2761.56 corner of a right knee showing the popliteus muscle with musculotendinous junction (1) popliteus mm), oblique popliteal ligament (average length, 45.5664.67 mm; average diameter, tendon (2), lateral collateral ligament (3), popliteo- 14.9064.67 mm), posterior meniscofemoral ligament (average length, 23.7563.17 fibular ligament (4), and lateral femoral condyle mm; average diameter, 3.6261.03 mm), and popliteomeniscal ligaments (average me- (5). Right5lateral, left5medial, top5superior, and diolateral popliteal hiatus diameter, 9.8362.16 mm; average superoinferior popliteal bottom5inferior. hiatus diameter, 8.2361.86 mm).

The authors are from the Department of Trauma Surgery and Sports Traumatology (MO, PT, KPB), Academic Hospital Feldkirch, Feldkirch; and the Division of Clinical and Functional Anatomy (KHK), Department of Anatomy, Histology and Embryology, Medical University Innsbruck, Innsbruck, Austria. The authors have no relevant financial relationships to disclose. Correspondence should be addressed to: Michael Osti, MD, Department of Trauma Surgery and Sports Traumatology, Academic Hospital Feldkirch, Carinagasse 47, 6800 Feldkirch, Austria (michael. [email protected]). doi: 10.3928/01477447-20130821-11

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he posterolateral corner (PLC) of adjacent bony landmarks. To the authors’ the knee has been identified as knowledge, no other study has extensively Tan essential stabilizing complex addressed these objectives. restraining varus, external rotation, and combined posterior translation and exter- Materials and Methods nal rotation of the tibia on the femur.1-5 Thirty cadaveric knee specimens from The posterolateral structures described 14 female and 16 male Caucasian donors in literature include the lateral collateral with no evidence of surgical scars and no ligament, popliteus tendon, popliteofibu- instability on clinical examination were lar ligament, fabellofibular ligament, and used for this study. Average age of the arcuate ligament.6-12 Several studies have donors at the time of death was 76.768.7 addressed the anatomy of the PLC,6-12 but years. Thirteen right and 17 left knees controversy exists regarding a standard- with at least 30 cm of bone and soft tissue ized nomenclature, the connective attach- proximal and distal to the joint line were ments and the relationships between them, investigated. No medical history exclud- and the frequency of occurrence among ing previous injuries was available. To all structures of the PLC.7,9,10,12 The use determine a consistent variable for com- of microsurgical techniques to precisely parison of the sample, the mediolateral 1 describe the anatomy and measurement and anteroposterior diameters of the tibial of the ligaments that form the PLC has plateau were used. Figure 1: Dorsal photograph of the posterolateral corner of a right knee showing the popliteus mus- been reported and has proven its potential Gross anatomic dissection was per- cle with musculotendinous junction (1) popliteus 7 to clarify some of the cited questions. formed using a magnifying loupe. For a tendon (2), lateral collateral ligament (3), popliteo- Numerous reconstructive procedures ad- precise dissection of the deep layers of fibular ligament (4), and lateral femoral condyle dressing acute and chronic PLC injuries the posterolateral aspect, a surgical mi- (5). Right5lateral, left5medial, top5superior, and bottom5inferior. have been developed to restore knee joint croscope and microsurgical instruments function and stability.2,13-19 were used. After removal of skin and To obtain an anatomic reconstruction, subcutaneous tissue en bloc, the iliotibial The presence of a fabella was next it is important to identify ligament attach- band was dissected from the Gerdy tu- noted in the lateral head of the gastroc- ment sites in acute trauma and chronic bercle from distal to proximal. The at- nemius muscle, and measurements of the instability when edema, hematoma, mul- tachments of the short and long heads of fabellofibular ligament were conducted in tiple avulsion or retraction, and scar tis- the biceps femoris muscle were released specimens in which it was present. After- sue formation impede the conception of from the femoral origin and reflected dis- ward, the lateral head of the gastrocne- normal anatomy. This necessitates pre- tally, allowing for a visualization of the mius muscle was detached. By dissect- cise quantitative and qualitative descrip- lateral collateral ligament and the pop- ing the deep layer of the popliteal fossa, tions that specify measurable parameters liteofibular ligament. The biceps femoris the inferolateral genicular neurovascular that characterize the ligaments and their tendon and its aponeurotic fibers blend- bundle was located and served as a guid- shapes and orientation and references all ing into the iliotibial band were traced ing structure to the PLC. The attachment structures involved in adjacent bony land- to the insertion site at the posterolateral of the popliteus muscle to the posterolat- marks. The current study also addressed aspect of the fibular head and were care- eral aspect of the tibia was exposed, and the oblique popliteal ligament, the pos- fully dissected to identify the margins its tendon was traced to the insertion at terior meniscofemoral ligament, and the and attachments of the lateral collateral the lateral femoral condyle, identifying anatomy and morphology of the popliteal ligament and the popliteofibular ligament the popliteofibular ligament attachment hiatus, including the popliteomeniscal at the posteromedial aspect of the fibu- at the musculotendinous junction (Figure ligaments.20,21 lar head. The lateral collateral ligament 1) and the anteroinferior and posterosupe- The objectives of this study were to extending from the styloid process to the rior popliteomeniscal ligaments extend- establish a comprehensive anatomy and lateral femoral condyle was dissected, ing to the lateral meniscus that form the morphometry of all structures that form and its dimensions were recorded. To ac- popliteal hiatus. For complete exposure the PLC using microsurgical exposure complish an exposure of the entire pop- of the popliteal hiatus, a transverse inci- techniques and to provide a reference liteus tendon, the lateral collateral liga- sion of the proximal insertion of the pos- system for the ligament insertion areas to ment had to be transected. terior capsule was performed. The fibers

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3A 3B 3C Figure 3: Schematic details of a right knee. Lateral view of the fibular head showing the fibular styloid process (1), fibular lateral collateral ligament insertion (2), and fibular popliteofibular ligament insertion (2). e15proximal and e25posterior distance between the lateral collateral ligament and popliteofibular ligament footprint. c15distal and c25posterior distance between the styloid process and popliteofibular ligament footprint (A). Posterior view of the fibular head showing the fibular styloid process (1) and fibular popliteofibular ligament insertion (3). c35medial distance between the styloid process and popliteofibular ligament footprint (B). Lateral view of the lateral femoral condyle showing the lateral femoral epicondyle (4), femoral lateral collateral ligament insertion (5), and femoral popliteus tendon insertion (6). a15proxi- 2 mal and a25posterior distance between the epicondyle and lateral collateral ligament footprint. b15distal and b25anterior distance between the epicondyle and popliteus tendon footprint. d15distal and d25an- Figure 2: Posteromedial photograph of the popli- terior distance between the lateral collateral ligament and popliteus tendon footprint (C). teal hiatus of a right knee showing the posterior cruciate ligament (1), posterior meniscofemoral ligament (2), popliteal hiatus with popliteus tendon (3), posterosuperior popliteomeniscal ligament (4), anteroinferior popliteomeniscal ligament (5), Results tibia and inserted into the anterior and lateral meniscus posterior horn (6), and popliteus Average mediolateral and the anteropos- proximal quarter of the popliteal sulcus. muscle (7). Right5posterolateral, left5anterome- terior diameters of the tibial plateau were The femoral attachment was anterior and dial, top5superior, and bottom5inferior. 78.3565.02 and 51.2266.20 mm, respec- distal to the lateral collateral ligament at- tively. All reference measurements refer to tachment and anterior and distal to the of the arcuate ligament extending between the midportion of the insertion areas and the lateral epicondyle. Average femoral pop- the fibular head and the posterior cap- center of the tubercles, respectively. liteus tendon footprint was 10.3661.80 sule were identified. Simultaneously, the mm in an anteroposterior direction and oblique popliteal ligament was dissected Lateral Collateral Ligament 6.0861.33 mm in a superoinferior direc- and studied. Its length was measured from The lateral collateral ligament was tion. Average length of the popliteus ten- the semimembranosus tendon origin to identified in all 30 knee specimens. Its don was 36.3664.53 mm, and average the capsular insertion. morphology was consistently a round and diameter was 8.4061.31 mm. After removal of the posterior capsule, well-defined structure with a slight intra- the posterior meniscofemoral ligament ligamentous rotation. The femoral attach- Popliteofibular Ligament was exposed (Figure 2). Relevant bony ment site was triangular, clearly definable, The popliteofibular ligament was landmarks on the fibular head and the lat- and located posterior and proximal to present in all 30 knee specimens. It orig- eral femoral condyle, including the most the lateral epicondyle. The fibular inser- inated from the popliteal musculotendi- proximal point of the styloid process and tion area on the anterolateral aspect of the nous junction, developed distally and an- the tip of the lateral femoral epicondyle, fibular head, slightly anterior and distal to teriorly with a mean angle of 51° (range, were simultaneously identified (Figure 3). the styloid process, had a fan-shaped mor- 47°-55°) to the longitudinal axis of the The center of the ligament insertion areas phology and blended with the attachment tibia, and inserted on the deep portion of and bony landmarks were marked with of the biceps femoris tendon. Quantita- the posterosuperior aspect of the styloid cannulas. For the quantitative measure- tive characteristics of the lateral collateral process with a fan-shaped footprint. The ment of the distances between the liga- ligament are shown in Table 1. popliteofibular ligament attachment was ment insertion areas and their reference to posterior and proximal to the lateral col- bony landmarks, a digital slide gauge was Popliteus Tendon lateral ligament fibular attachment and used. The metering precision of the instru- The popliteus tendon originated from distal, posterior, and medial to the tip ment is accurate to 0.01 mm. the posteromedial aspect of the proximal of the fibular styloid process. Morpho-

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Table 1 Quantitative Characteristics of Ligaments and Insertion Areas

Mean6SD, mm Ligament/ Insertion Area Length Diameter Femoral Footprint Fibular Footprint LCL 61.6963.95 5.4761.14 9.8961.66 AP, 9.4261.42 AP, 10.4161.74 SI 7.4961.92 SI PT 36.3664.53 8.4061.31 10.6361.80 AP, 6.0861.33 SI PFL 14.0663.20 A, 6.5961.69 insertion, 4.9261.59 AP, 12.4562.21 P 7.0462.31 midportion 5.5362.20 ML FFL 33.7964.98 4.0461.22 5.8761.67 ML, 3.7660.53 ML, 3.8462.44 SI 4.2061.33 SI AL 31.5462.82 7.2761.56, 12.2862.56 capsule 5.6361.76 AP, max width 6.8665.12 6.2961.30 SI OPL 45.5664.67 14.9064.67 pMFL 23.7563.17 3.6261.03 Popliteal hiatus 9.8362.16 ML, 8.2361.86 SI Abbreviations: A, anterior; AL, arcuate ligament; AP, anteroposterior; FFL, fabellofibular ligament; LCL, lateral collateral ligament; max, maximum; ML, mediolateral; OPL, oblique popliteal ligament; P, posterior; PFL, popliteofibular ligament; pMFL, posterior meniscofemoral ligament; PT, popliteus tendon; SI, superoinferior.

logical variations consisted of a singular depended on the presence of a fabella and erable variability. The ligament crosses bundle, a double ligament, or an inverted was difficult to distinguish from the arcuate the popliteus tendon superficial and the Y-shaped structure. A separated ante- ligament in specimens without a fabella. oblique popliteal ligament profound. Fi- rior and posterior bundle was found in 8 Average length of the fabellofibular liga- bers from the popliteus muscle blend into (26.7%) specimens and a Y-shaped ligament was 33.7964.98 mm, and average the ascending limb of the arcuate ligament in 4 (13.3%) specimens. Eighteen diameter was 4.0461.22 mm. ment. The arcuate ligament was a narrow (60%) specimens had a single anterior Average femoral footprint was and thin fiber bundle found in 18 (60%) or posterior ligament. Length, diameter, 3.8462.44 mm in a superoinferior direc- knees. The quantitative characteristics of and footprint dimensions are shown in tion and 5.8761.67 mm in a mediolateral the arcuate ligament and its footprints are Table 1. direction. Average fibular footprint was shown in Table 1. 4.2061.33 mm in a superoinferior direc- Fabellofibular Ligament tion and 3.7660.53 mm in a mediolateral Oblique Popliteal Ligament The fabellofibular ligament was iden- direction. The oblique popliteal ligament origi- tified in 12 (40%) of the dissected knees. nates from the posterior surface of the It originated from the lateral aspect of the Arcuate Ligament tibial head, blends with fibers from the fabella (if a fabella was present) and the The arcuate ligament was found in all semimembranosus tendon, develops me- posterior aspect of the supracondylar pro- knee specimens. It originated from the diolaterally, and attaches at the upper cess of the femur, and it blended with fibers posterior capsule and the cap of the lateral margin of the intercondylar fossa and the from the lateral gastrocnemius muscle. The femoral condyle and formed a triangular posterior surface of the femur, blending insertion was on the posterior and lateral structure thickening the posterior capsule. into the posterior capsule. Some of its edge of the fibular styloid process. The fib- The insertion area was on the lateral edge fibers connect to the lateral aspect of the ular attachment of the fabellofibular liga- of the fibular styloid process just lateral to fabella and to the arcuate ligament, form- ment blended with the fibers of the arcu- the popliteofibular ligament attachment. ing a round, arch-shaped structure within ate ligament in 7 (23.3%) specimens. The The arcuate ligament is a stabilizing struc- the posterolateral capsule. The ligament occurrence of the fabellofibular ligament ture against hyperextension with consid- width was variable in this study. A broad

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and distinctive structure was found in 7 mm between the (23.3%) specimens, whereas a weak fi- femoral lateral Table 2 ber bundle was found in 4 (13.3%). Av- epicondyle and Distances Between Ligament Insertion Area erage length and width of the oblique the lateral col- and Bony Landmarks popliteal ligament were 45.5664.67 and lateral ligament 14.9064.67 mm, respectively. footprint posteri- Ligament Insertion Area and Bony Landmark Mean6SD, mm or. The popliteus Femoral lateral epicondyle to LCL proximal (a1) 3.6160.75 Popliteomeniscal Ligament tendon insertion Femoral lateral epicondyle to LCL posterior (a2) 3.8160.87 The popliteomeniscal fascicles were was an average Femoral lateral epicondyle to PT distal (b1) 6.4360.77 identified in all knee specimens. Arising of 6.4360.77 Femoral lateral epicondyle to PT anterior (b2) 4.2461.53 from the anterior surface of the popliteal mm distal and Fibular styloid process to PFL distal (c1) 2.3161.06 tendon on the level of the posterior transi- 4.2461.53 mm tion area between joint cartilage and tibial anterior to the Fibular styloid process to PFL posterior (c2) 4.5262.54 bone, 2 well-defined bundles confined the femoral lateral Fibular styloid process to PFL medial (c3) 4.3962.80 popliteal hiatus. The posterosuperior fas- epicondyle. The LCL to PT distal (d1) 5.6961.36 cicle was attached to the superior border of popliteofibular LCL to PT anterior (d2) 4.9761.73 the posterior horn of the lateral meniscus, ligament footprint PFL to LCL fibular proximal (e1) 16.5765.72 and the anteroinferior fascicle was attached was an average of PFL to LCL fibular posterior (e2) 10.2665.17 to the bottom edge of the posterior horn of 2.3161.06 mm Abbreviations: LCL, lateral collateral ligament; PFL, popliteofibular the lateral meniscus. Average diameter of distal, 4.5262.54 ligament; PT, popliteus tendon. the popliteal hiatus was 9.8362.16 mm mm posterior, in a mediolateral direction and 8.2361.86 and 4.3962.80 mm in a superoinferior direction. mm medial to the fibular styloid process. Average distance crosurgical techniques superior for estab- Posterior Meniscofemoral Ligament between the lateral collateral ligament in- lishing accurate descriptions of anatomic The posterior meniscofemoral liga- sertion and popliteus tendon insertion was components of this region. ment extends between the medial side 5.6961.36 mm distal and 4.9761.73 mm wall of the femoral intercondylar groove anterior. Average popliteofibular ligament Lateral Collateral Ligament and the posterior horn of the lateral me- footprint was 16.5765.72 mm proximal Average length and diameter of the lat- niscus. Its fibers originate proximal to the and 10.2665.17 mm posterior from the eral collateral ligament were 61.6963.95 femoral posterior cruciate ligament (PCL) fibular lateral collateral ligament insertion mm and 5.4761.14 mm, respectively, attachment and remain superficial and area. The results of referencing the ligament which are comparable to the results of posterior to the PCL. The posterior me- insertion areas to each other and to adjacent Espregueira-Mendes and da Silva,8 who niscofemoral ligament orientates laterally bony landmarks are shown in Table 2. reported an average length of 63.165.2 at the cartilage surface level and blends mm and average width of 8.562.2 mm, into the most posterior aspect of the lat- Discussion and with the results of additional stud- eral meniscus beneath the aperture of the The objectives of this study were to ies.3,5,7,9,15 Average dimensions of the an- popliteal hiatus. The prevalence of the provide quantitative and qualitative data teroposterior and superoinferior axis of the posterior meniscofemoral ligament was on the posterolateral structures and to femoral footprint were also in accordance 83.3% in this study. Average length of the reference them to identifiable bony land- with previous reports,7,8 with Espregueira- posterior meniscofemoral ligament was marks. Based on previous reports,6,8,9 the Mendes and da Silva8 reporting dimen- 23.7563.17 mm, and average diameter current authors used the lateral epicondyle sions of 10.960.1 mm superoinferior and was 3.6261.03 mm. The results for liga- on the femur and the tip of the styloid 1060.1 mm anteroposterior. The dimen- ment length, diameter, and insertion areas process on the fibula to describe the liga- sions of the anteroposterior and superoin- are shown in Table 1. ments’ relationship to each other in a re- ferior axis of the fibular footprint7,8 aver- Average distance between the liga- producible way. They attempted to clarify aged 9.4261.42 mm and 7.4961.92 mm, ment insertion area and bony landmarks the confusion in the literature originating respectively. Regarding the reference of was 3.6160.75 mm between the femoral from inconsistent terminology and a vari- the lateral collateral ligament femoral at- lateral epicondyle and the lateral collateral ety in anatomy by incorporating all known tachment to the lateral femoral epicondyle, ligament footprint proximal and 3.8160.87 ligamentous structures and by using mi- a posterior distance of 3.8160.87 mm

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was found, which supports the findings was 6.5961.69 mm at the insertion and the fibular footprint was 4.2061.33 mm of LaPrade et al9 (3.1 mm posterior), but 7.0462.31 mm at the midportion. These in the superoinferior axis and 3.7660.53 the proximal distance was more than twice results are similar to those reported by mm in the mediolateral axis. Average that found by LaPrade et al9 (3.6160.75 vs Diamantopoulos et al.7 femoral footprint was 3.8462.44 mm in 1.4 mm proximal, respectively). Average fibular insertion area was the superoinferior axis and 5.8761.67 4.9261.59 mm in an anteroposterior di- mm in the mediolateral axis. To the au- Popliteus Tendon rection and 5.5362.20 mm in a medio- thors’ knowledge, no comparable data ex- Average length and diameter of the lateral direction. To the authors’ knowl- ist in the literature. popliteus tendon were 36.3664.53 and edge, no comparable reports exist in the The arcuate ligament was found in all 8.4061.31 mm, respectively. Average literature regarding the fibular footprint. knee specimens in the current study. Su- length of the anteroposterior and supero- Brinkman et al6 reported a mean distance dasna and Harnsiriwattanagit22 reported a inferior axes of the femoral footprint were of 11.2 mm anterior and 12.3 mm distal frequency of occurrence of 24%. Diaman- 10.6361.80 and 6.0861.33 mm, respec- between the fibular lateral collateral liga- topoulos et al7 and Watanabe et al24 found tively. In this study, the femoral footprint ment and popliteofibular ligament inser- the arcuate ligament in 70% and 47.9% of had dimensions approximately equal to tion, whereas the current study reports 10 and 115 cadaveric knees, respectively. those reported in the only previous report distances of 10.2665.17 and 16.5765.72 It is unclear whether the amount of dis- on the dimensions of the femoral foot- mm, respectively. Average distances be- sected knee specimens, the variability in print.7 Average distances between the tween the fibular styloid process and the existing nomenclature, or the influence of femoral lateral epicondyle and popliteus popliteofibular ligament were 2.3161.06 magnification instruments is responsible tendon were 6.4360.77 mm distally and mm distally, 4.5262.54 mm posteriorly, for the inhomogeneity of these differing 4.2461.53 mm anteriorly, which are simi- and 4.3962.80 mm medially. LaPrade et results. It was difficult to separate the ar- lar to results reported by Brinkman et al6 al9 reported a mean distance between the cuate ligament from the oblique popliteal (mean distance, 9.763.9 mm distal to the popliteofibular ligament attachment and ligament and the posterior capsule in spec- epicondyle). Average distances between the tip of the styloid process of 2.8 mm imens where only a weak and narrow fiber the femoral lateral collateral ligament in- (range, 1.2-3.8 mm) for the anterior divi- bundle was present. Average length of the sertion and popliteus tendon insertion were sion and 1.6 mm (range, 0.6-2.8 mm) for anteroposterior and superoinferior axes 5.6961.36 mm distally and 4.9761.73 the posterior division of the popliteofibu- of the fibular footprint were 5.6361.76 mm anteriorly, which is less distally and lar ligament. and 6.2961.30 mm, respectively. To the more anteriorly compared with the results authors’ knowledge, no comparable data of Brinkman et al6 (average, 1160.8 mm Fabellofibular, Arcuate, and Oblique exist in the literature. distally and 0.8464 mm anteriorly). Popliteal Ligaments The oblique popliteal ligament con- The fabellofibular, arcuate, and oblique nects the medial to the lateral corner of Popliteofibular Ligament popliteal ligaments are only sporadically the posterior aspect of the knee joint and The popliteofibular ligament was mentioned in the literature. Watanabe et blends with fibers of the arcuate ligament found in all specimens, which supports al24 found the fabellofibular ligament in and the fabellofibular ligament. The fre- previous reports in the literature of an in- 51.3% and the arcuate ligament in 47.9% quency of occurrence was 100%. Aver- cidence between 93% and 100%.7,9,16,22 of 115 dissected cadaveric knees. In the age length and width were 45.5664.67 The ligament’s construction seems to current study, average length and diam- and 14.9064.67 mm, respectively. To the be polymorphic. Although Stäubli and eter of the fabellofibular ligament were authors’ knowledge, no comparable data Birrer23 and LaPrade et al9 consistently 33.7964.98 and 4.0461.22 mm, respec- exist in the literature. found a structure with 2 separate divi- tively. The relative frequency of occur- sions, the current study’s findings confirm rence was 40%. The ligament’s position Popliteal Hiatus the results of Diamantopoulos et al,7 who is lateral to the arcuate ligament, and the The anteroinferior and the posterosu- classified 3 different types of the popliteo- separation from the latter was difficult in perior popliteomeniscal fascicles were fibular ligament: single bundle, double some specimens, indicating a more fre- clearly identified in all knee specimens. bundle, and inverted y-shaped. The dis- quent presence than previously estimat- The majority of studies agree that the con- tribution in the current study was 60%, ed.25 The fibular insertion at the posterior nective attachments of the popliteus ten- 26.7%, and 13.3%, respectively. Average and lateral edge of the styloid process in don to the lateral meniscus contribute to length was 14.0663.20 mm anterior and the current study confirms the findings of stabilization and retraction, and, therefore, 12.4562.21 mm posterior. Average width Diamantopoulos et al.7 Average length of the protection of the lateral meniscus.

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Posterior Meniscofemoral Ligament structive techniques for the PLC regarding 13. Cooper JM, McAndrews PT, LaPrade RF. Posterolateral corner injuries of the knee: Average length and diameter of the graft position, graft orientation, and selec- anatomy, diagnosis and treatment. Sports posterior meniscofemoral ligament were tion of tunnel position and diameter. Med Arthrosc Rev. 2006; 14:213-220. 23.7563.17 and 3.6261.03 mm, respec- 14. Jung YB, Jung HJ, Kim SJ, et al. Posterolat- tively. Its prevalence was 83.3%. Both References eral corner reconstruction for posterolateral rotatory instability combined with posterior measurements are comparable with those 1. LaPrade RF, Tso A, Wentorf FA. Force mea- cruciate ligament injuries: comparison be- in previous reports in the literature.20 surements on the fibular collateral ligament, tween fibular tunnel and tibial tunnel tech- popliteofibular ligament and popliteus ten- niques. Knee Surg Sports Traumatol Ar- Some inaccuracy remains when compar- don to applied loads. Am J Sports Med. 2004; throsc. 2008; 16:239-248. ing the results of studies using different 32:1695-1701. 15. Khanduja V, Somayaji HS, Harnett P, Utuku- methods and materials. The use of speci- 2. LaPrade RF, Johansen S, Wentorf FA, Enge- ri M, Dowd GSE. Combined reconstruction mens from patients aged an average of bretsen L, Esterberg JL, Tso A. An analysis of chronic posterior cruciate ligament and of an anatomical posterolateral knee recon- posterolateral corner deficiency.J Bone Joint 76.768.7 years limited the current study struction. An in vitro biomechanical study Surg Br. 2006; 88:1169-1172. because patients requiring PLC surgery and development of a surgical technique. Am J Sports Med. 2004; 32:1405-1414. 16. Kim JG, Ha JG, Lee YS, Yang SJ, Jung JE, are predominantly younger. Moreover, no Oh SJ. Posterolateral corner anatomy and its medical history of the donors was avail- 3. LaPrade RF, Bollom TS, Wentorf FA, Wills anatomical reconstruction with single fibula NJ, Meister K. Mechanical properties of the and double femoral sling method: anatomical able to exclude previous injuries of the posterolateral structures of the knee. Am J study and surgical technique. Arch Orthop PLC. The sample size was not determined Sports Med. 2005; 33:1386-1391. Trauma Surg. 2009; 129:381-385. because a power analysis is difficult to 4. Markolf KL, Wascher DC, Finerman GAM. 17. LaPrade RF, Wentorf F. Diagnosis and treat- The effect of section of the posterolateral struc- conduct with this type of data. ment of posterolateral knee injuries. Clin Or- tures. J Bone Joint Surg Am. 1993; 75:387-394. thop Relat Res. 2002; 402:110-121. 5. Sugita T, Amis AA. Anatomic and biome- 18. LaPrade RF, Johansen S, Agel J, Risberg MA, Conclusion chanical study of the lateral collateral and Moksnes H, Engebretsen L. Outcomes of an Concerning the most frequently and ac- popliteofibular ligaments. Am J Sports Med. anatomic posterolateral knee reconstruction. 2001; 29:466-472. J Bone Joint Surg Am. 2012; 92:16-22. curately studied components of the PLC of 6. Brinkman JM, Schwering PJA, Blankevoort 19. Zhang H, Feng H, Hong L, Wang X, Zhang the knee, this study confirms the results L, Koolos JG, Luites J, Wymenga AB. The J. Popliteofibular ligament reconstruction for previously reported in the literature. How- insertion geometry of the posterolateral cor- posterolateral external rotation instability of ever, the current study found a more proxi- ner of the knee. J Bone Joint Surg Br. 2005; the knee. Knee Surg Sports Traumatol Ar- 87:1364-1368. throsc. 2009; 17:1070-1077. mal position of the lateral collateral liga- 7. Diamantopoulos A, Tokis A, Tzurbakis M, 20. Amis AA, Gupte CM, Bull AMJ, Edwards ment footprint on the lateral femoral Patsopoulos I, Georgoulis A. The postero- A. Anatomy of the posterior cruciate liga- epicondyle and a more distal and anterior lateral corner of the knee: evaluation under ment and the meniscofemoral ligaments. microsurgical dissection. Arthroscopy. 2005; position of the popliteus tendon insertion Knee Surg Sports Traumatol Arthrosc. 2006; 21:826-833. 14:257-263. area relative to the lateral collateral liga- 8. Espregueira-Mendes, da Silva MV. Anatomy 21. Bozkurt M, Elhan A, Tekdemir I, Tönük E. ment footprint. This study provides addi- of the lateral collateral ligament: a cadaver An anatomical study of the meniscofibular tional information regarding the popliteus and histological study. Knee Surg Sports ligament. Knee Surg Sports Traumatol Ar- Traumatol Arthrosc. 2006; 14:221-228. tendon femoral footprint; the quantitative throsc. 2004; 12:429-433. 9. LaPrade RF, Ly TV, Wentorf FA, Engebret- characteristics of the fabellofibular, arcu- 22. Sudasna S, Harnsiriwattanagit K. The liga- sen L. 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Knee Surg femoral and fibular insertion areas, may Sports Traumatol Arthrosc. 2007; 15:895-900. 24. Watanabe Y, Moriya H, Takahashi K, et al. Functional anatomy of the posterolateral help develop a more standardized nomen- 11. Shahane SA, Ibbotson C, Strachan R, Bick- structures of the knee. Arthroscopy. 1993; clature. Microsurgical exposure tech- erstaff DR. The popliteofibular ligament. An 9:57-62. anatomical study of the posterolateral cor- niques are necessary for accurate prepara- ner of the knee. J Bone Joint Surg Br. 1999; 25. De Maseneer M, Shahabpour M, Vanderdood tion resulting in precise measurements. 81:636-642. K. Posterolateral supporting structures of the knee: findings on anatomic dissection, ana- The current method of referencing liga- 12. Wadia FD, Pimple M, Gajjar SM, Narvekar tomic slices and MR imaging. Eur Radiol. ment footprints to adjacent bony land- AD. An anatomic study of the popliteofibular 2001; 11:2170-2177. ligament. Int Orthop. 2003; 27:172-174. marks may be helpful for surgical recon-

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