Current Management of Posterior Wall Fractures of the Acetabulum

Home , Acetabular fracture, Acetabulum, Joint dislocation

Berton R. Moed, MD Philip J. Kregor, MD Mark C. Reilly, MD Michael D. Stover, MD Mark S. Vrahas, MD

Abstract regardless of the treatment, the results The general goals for treating an acetabular fracture are to restore congruity and stability after a hip injury would be poor if there of the hip joint. These goals are no different from those for the subset of fractures of the was residual joint instability or incon- posterior wall. Nevertheless, posterior wall fractures present unique problems compared gruity between the femoral head and with other types of acetabular fractures. Successful treatment of these fractures depends on the weight-bearing area of the acetab- a multitude of factors. The physician must understand their distinctive radiologic features, ulum.1-4 In subsequent decades, evalu- in conjunction with patient factors, to determine the appropriate treatment. By knowing ation and treatment protocols, which the important points of posterior surgical approaches to the hip, particularly the posterior are still considered optimal, were de- wall, specifi c techniques can be used for fracture reduction and fi xation in these often veloped and refi ned by Letournel and challenging fractures. In addition, it is important to develop a complete grasp of potential Judet5 and published in their defi nitive complications and their treatment. The evaluation and treatment protocols initially devel- 1993 text. New information and emerg- oped by Letournel and Judet continue to be important; however, the surgeon also should ing trends have appeared in other book be aware of new information published and presented in the past decade. and journal articles, including Instruc- Instr Course Lect 2015;64:139–159. tional Course Lectures.6,7 However, these publications have focused primarily on An acetabular fracture routinely re- confl icting recommendations for both the entire spectrum of acetabular frac- quires surgical intervention. The liter- nonsurgical and surgical treatment reg- tures, with limited discussion of poste- ature from the 1950s and 1960s offered imens.1,2 It was agreed, however, that rior wall fracture treatment. Posterior wall fractures are the most common type, accounting for approximately 25% Dr. Moed or an immediate family member has received royalties from Biomet and serves as a board member, owner, offi cer, or committee member of AO North America and the AO Foundation. Dr. Kregor or an immediate family member is a of all acetabular fractures, and are often member of a speakers’ bureau or has made paid presentations on behalf of Medtronic. Dr. Reilly or an immediate family treated at community medical facilities.5 member is a member of a speakers’ bureau or has made paid presentations on behalf of Stryker. Dr. Vrahas or an immediate With these facts in mind, it is import- family member serves as a board member, owner, offi cer, or committee member of the AO Foundation. Neither Dr. Stover nor any immediate family member has received anything of value from or has stock or stock options held in a commercial ant to refocus on this common—but company or institution related directly or indirectly to the subject of this chapter. potentially debilitating—injury by

Figure 3 Schematic diagram showing the posterior border of the innominate bone (1) and anterior Figure 1 Schematic diagram rim of the acetabulum (2) as seen showing the six acetabular land- Figure 2 Schematic diagram on an iliac oblique radiograph. The marks seen on an AP radiograph: showing the iliopectineal line (1) iliac wing is seen en face. The ante- (1) iliopectineal line, (2) ilioischial and the posterior rim (2) as seen rior rim of the acetabulum can best line, (3) U or teardrop, (4) roof, (5) on an obturator oblique radiograph. be seen with this view. The proper anterior rim, and (6) posterior rim. The obturator ring is seen en face. amount of rotation for the iliac (Reproduced from Templeman D, The proper amount of rotation for oblique view (inset) is present when Olson S, Moed BR, Duwelius P, the obturator oblique view (inset) is the tip of the coccyx lies just above Matta JM: Surgical treatment of present when the tip of the coccyx the center of the contralateral femo- acetabular fractures. Instr Course lies just above the center of the ral head. (Adapted from Templeman Lect 1999;48:481-496.) ipsilateral femoral head. (Adapted D, Olson S, Moed BR, Duwelius from Templeman D, Olson S, Moed P, Matta JM: Surgical treatment of acetabular fractures. Instr Course reviewing the unique fracture radiolo- BR, Duwelius P, Matta JM: Surgical treatment of acetabular fractures. Lect 1999;48:481-496.) gy, surgical indications and techniques, Instr Course Lect 1999;48:481- pitfalls, and complications of posterior 496.) wall fractures. classifi cation of posterior wall frac- Radiology of the Acetabulum tures, as with all acetabulum fractures, and Posterior Wall continues to be determined primarily Fracture Classification by analyzing the aforementioned plain The plane of the ilium is approximately radiographic projections and two- 90° to the plane of the obturator fora- dimensional CT scans (Figures 1, 2, men, and both structures are oriented 3, and 4). approximately 45° to the frontal plane. On the AP view, the rim of the pos- On this basis, Judet et al8 proposed that terior wall approximates a straight line the AP view and two 45° oblique views and is more vertical than the anterior of the pelvis can be used to study the wall (Figure 5). Any break or defi cit in radiographic anatomy of the acetabu- this line indicates fracture or displace- Figure 4 Axial CT scan showing lum. Thus, the fi rst systematic classi- ment of the posterior rim of the ace- a section through the acetabulum in which the posterior wall is frac- fi cation of acetabular fractures based tabulum. The signs of hip dislocation tured (black arrows) with marginal on the anatomic pattern was derived, on the AP view include a break in the impaction (white arrowhead). An which later incorporated the analysis of Shenton line, proximal migration of the intra-articular loose body appears between the femoral head and the 5 two-dimensional CT scans. Although lesser trochanter, relatively smaller size acetabulum (white arrow). (Copy- three-dimensional CT technology of the affected femoral head (closest to right Berton R. Moed, MD, St. has progressed, the diagnosis and the the x-ray cassette), and a bony double Louis, MO.)

Table 1 Additional Information Provided by a CT Scan

Intra-articular bony fragments Intra-articular osteochondral fragments Size of the posterior wall fracture Location of the posterior wall fracture Number of posterior wall fragments Figure 5 AP radiograph showing Rotation of the fracture fragments a dislocated right hip and a poste- Figure 6 Two-dimensional CT Marginal impaction of the articular rior wall fracture. (Copyright Berton section of the hip of the patient surface R. Moed, MD, St. Louis, MO.) in Figure 5. (Copyright Berton R. Moed, MD, St. Louis, MO.) Fractures of the femoral head density above the femoral head. The Table 2 double density (Figure 5) is the poste- Letournel and Judet Classifi cation of Acetabular Fractures rior wall fragment. It often sits atop the dislocated femoral head and can give Elementary Fracture Types Associated Fracture Types the appearance of normal joint space, Posterior wall Posterior column and posterior wall potentially resulting in a misdiagnosis. Posterior column Transverse and posterior wall The obturator oblique view is espe- Anterior wall T-shaped cially helpful in diagnosing a posterior Anterior column Anterior column and posterior hemitransverse wall fracture because it places the pos- Transverse Both-column terior wall almost perpendicular to the x-ray beam and minimizes overlay of the anterior wall (Figure 2, inset). A into a system consisting of 10 fracture fracture line (type 62-A1.3, the so-called dislocated hip will become more ob- types: 5 elementary types and 5 associ- marginal impaction; Figure 7). These vious on the obturator oblique view.9 ated (or combined) types5,8 (Table 2). subgroups are then further categorized The iliac oblique view does not provide The Orthopaedic Trauma Association (Table 3). additional information specifi c to the (OTA) comprehensive fracture classifi - A potential point of confusion in posterior wall—other than showing cation system uses a basic alphanumeric the OTA classifi cation is the use of the posterior border of the innominate coding of the acetabular fracture clas- “fracture-dislocation” in the subgroup bone (greater and lesser sciatic notch), sifi cation developed by Letournel and descriptions. It is well known that frac- which may be involved in an extended Judet and offers no clinical advantage. tures of the posterior wall can occur fracture. The CT scan provides addi- However, the OTA system is often used without any history of dislocation of tional information specifi c to posterior to allow computerized categorization the hip joint.11 Acetabular fractures en- wall fractures that is not readily appar- and subclassifi cation of the fracture compass a broad spectrum of injuries ent on plain radiographs (Table 1). types.10 The posterior wall fracture is that are artifi cially separated by the clas- The contiguous sections should have a codifi ed in the OTA system as type 62- sifi cation systems into specifi c types. slice thickness of no more than 3 mm A1 and is separated into three basic sub- As such, there are many transitional to provide satisfactory evaluation of the groups: fractures with a single posterior types. For example, the type originally posterior wall (Figures 4 and 6). fragment (type 62-A1.1), fractures with classifi ed as a posteroinferior posterior The classifi cation of acetabular frac- multiple fragments (type 62-A1.2), and wall fracture, with its extension supe- tures is based on a method originally fractures with osteochondral fragments riorly into the greater sciatic notch and developed in the 1960s by Letournel that are impacted into the underlying inferiorly into the ischium5 (Figure 8), and Judet,5,8 which was later refi ned cancellous bone medial to the primary behaves more like a fracture of the

Figure 7 Orthopaedic Trauma Association classiﬁ cation showing the three subgroups of posterior wall fractures of the acetabulum. (Adapted from Baumgaertner MR: Fractures of the posterior wall of the acetabulum. J Am Acad Orthop Surg 1999;7:54-65.)

Table 3 Orthopaedic Trauma Association Classiﬁ cation of Posterior Wall Fractures

One Fragment Multifragmented With Marginal Impaction (Type 62-A1.1) (Type 62-A1.2, a*) (Type 62-A1.3, a*) (1) Posterior (1) Posterior (1) Posterior (2) Posterior superior (2) Posterior superior (2) Posterior superior (3) Posterior inferior (3) Posterior inferior (3) Posterior inferior

The a* qualifi ers are represented as follows: a1 = one fragment; a2 = two fragments; a3 = more than two fragments. posterior column. It is now classifi ed determine the specifi c pattern of the as a posterior column fracture.10 acetabular fracture. Isolated fractures of the posterior wall occur with the hip in Preoperative Assessment neutral to 25° of adduction.5 The degree and Indications for Surgery of hip fl exion at the time of impact de- Most patients who sustain isolated pos- termines the level of the posterior wall Figure 8 Illustration of a fracture terior wall fractures of the acetabulum fracture (for example, 90° for a poste- originally classifi ed as a postero- are injured in motor vehicle crashes.11,12 rior fracture, 60° for a posterosuperior inferior posterior wall fracture but However, such fractures also can oc- fracture, and 115° for a posteroinferior now classifi ed as a posterior column fracture. (Copyright Berton R. 5 cur as the result of being struck by a fracture). When the knee is fl exed, the Moed, MD, St. Louis, MO.) motor vehicle or a fall from a height. impact occurs at the knee, such as in Lower-energy mechanisms, such as a dashboard injury. When the knee is other musculoskeletal and visceral in- sports-related trauma or simple falls, extended, the impact occurs at the foot. juries. Therefore, it is important obtain also can cause an acetabular fracture.5,11 In a motor vehicle crash, the force is a careful patient history and perform a The injuring force is commonly applied transmitted through the brake pedal complete physical examination. axially through the femoral shaft, caus- or the fl oorboard. Because posterior Patients with posterior wall frac- ing the femoral head to impact the pos- wall fractures of the acetabulum usu- tures of the acetabulum typically but terior acetabular wall.5 The position ally result from high-energy blunt trau- not always present to the emergency de- of the hip at the time of injury will ma, they are frequently associated with partment with hip pain. The surgeon,

therefore, must have a high level of (Figure 5). Prompt reduction is re- because of the lack of sensitivity and suspicion for any lower extremity in- quired because the rate of osteonecrosis specifi city of these measurements.15 jury that potentially causes abnormal increases dramatically if reduction is not Even experts in the fi eld cannot make loading of the hip joint. Dislocation of performed within 12 hours of the dis- this determination using the patient his- the femoral head occurs in more than location.11,13,14 With adequate sedation tory, plain radiographs, and CT scans.16 85% of patients with a posterior wall and pain medication, reduction often Therefore, it is safest to assume that the fracture.11 However, the absence of clin- can be performed in the emergency de- hip is unstable unless proved otherwise. ical signs of a dislocated hip or the lack partment. Closed reduction in the oper- Dynamic fl uoroscopic stress tests per- of a history of hip dislocation does not ating room using general anesthesia is formed under general anesthesia (ex- preclude the presence of a substantial indicated after an initial failed attempt amination under anesthesia) should be posterior wall fracture.11,13 There should at closed reduction in the emergency used to select patients for nonsurgical be shortening of the entire limb if the department, when there are contraindi- treatment, as an alternative to surgical hip is dislocated. However, shortening cations to the use of conscious sedation, procedures on all posterior wall frac- of 1 to 2 cm is often diffi cult to de- or because of physician preference. Im- tures of the acetabulum.17 When it ap- termine in the clinical setting, and the mediately after reduction, radiographs pears that the hip joint is congruent and physical fi ndings regarding limb po- should be obtained to confi rm a reduc- should be stable, or stability is equivo- sition commonly described for a pure tion of the dislocation. A postreduction cal (such as with smaller posterior wall posterior dislocation of the hip (fl exion, CT scan is not universally required to fractures), a dynamic stress examination adduction, and internal rotation of the confi rm a concentric reduction; how- should be performed to evaluate sta- hip with a shortened lower extremity) ever, it provides valuable additional bility before deciding on nonsurgical may not be present. information and is generally recom- management.17 There are several reasons for this sit- mended. A dislocated hip that cannot An examination under anesthesia uation. First, posterior wall fractures be reduced by closed means requires should be performed using the method can occur with or without an associated urgent open reduction and internal described by Moed et al14,15,17 in which frank dislocation of the hip joint. In ad- fi xation (ORIF) of the posterior wall the patient is placed supine with the hip dition, the presence of a large posterior fracture. in neutral rotation and full extension wall fracture allows the femoral head to All stable, concentrically reduced while under anesthesia. The hip is then dislocate directly posteriorly, without posterior wall fractures can be con- slowly fl exed past 90°, with progressive forcing the proximal femur into this sidered for nonsurgical management. manual force applied through the hip abnormal position (Figures 5 and 6). A With the hip stable and concentrically along the longitudinal axis of the femur patient who initially sustains a posterior reduced, the presence of small intra- while the hip is visualized with C-arm wall fracture-dislocation may have had articular fragments, such as those resid- image intensifi cation. The applied force the dislocation inadvertently reduced ing in the acetabular fossa identifi ed by should be substantial, with the exam iner by emergency personnel on the scene CT, does not alter this situation. A his- using his or her entire body weight to while being stabilized for transport to tory of hip dislocation is not necessarily axially load the hip through the femur. the hospital. The patient who presents an indication for surgical treatment. The examination is performed twice, in the “classic” dislocated hip position CT-based measurements for poste- using both AP and obturator oblique probably will have either a relatively rior wall fracture size are not reliable image intensifi er projection. If the hip small posterior wall fracture fragment predictors of a stable hip joint. Using joint remains congruent during this as- or a pure posterior dislocation. Normal the measurement method described sessment, the examination is repeated limb positioning does not preclude the by Moed et al,14,15 a posterior wall frag- by adding about 20° of adduction and presence of a posterior wall fracture and ment shown on a CT scan to involve about 20° of internal rotation, which actually may be associated with a large 50% or more of the joint surface can elicits instability more than fl exion posterior wall fracture fragment. be assumed to be unstable. However, alone. Frank hip dislocation is neither Dislocation of the hip can be di- any lesser involvement has little value required nor clinically desirable. Poste- agnosed on the initial AP radiograph for determining hip joint stability status rior subluxation demonstrated in either

be considered when there are medical contraindications to anesthesia or severe osteopenia exists that precludes stable internal fi xation. Older patients with severely comminuted fractures may be better treated with total hip arthroplasty (THA).11,13 In general, patients older than 55 years with more than three intra-articular fragments and marginal impaction should be considered as potential candidates for THA, rather than ORIF. However, the decision to proceed with THA is based on many factors and is a judgment call Figure 9 Image intensifi cation views showing dynamic fl uoroscopic exam- based on the surgeon’s experience. ination under anesthesia in a patient with a small posterior wall fracture. A, The intraoperative obturator oblique view with the hip in neutral rotation and fl exed to approximately 90° shows a located and congruent hip joint. Surgical Approach Options B, The subsequent intraoperative obturator oblique view with the hip in neutral Most posterior wall fractures can be rotation and fl exed to approximately 90° with axial load applied shows gross addressed with a standard Kocher- subluxation with loss of hip joint parallelism and joint congruency (arrow) and 5 gross enlargement of the medial clear space (arrowhead). (Reproduced with Langenbeck approach. However, for permission from Moed BR, Ajibade DA, Israel H: Computed tomography as a a superior posterior wall fracture (Fig- predictor of hip stability status in posterior wall fractures of the acetabulum. ure 10), modifi cations of this standard J Orthop Trauma 2009;23:7-15.) approach may be necessary for adequate visualization without surgical devital- view (indicated by a widening medial intra-articular osteochondral fragments, ization of the gluteus medius muscle joint space or a loss of joint parallel- while awaiting surgical treatment. and the superior gluteal neurovascular ism) indicates dynamic hip instability Commonly, acetabular fracture sur- bundle. The modifi ed approaches are (Figure 9). gery is performed between 2 and 5 days the Kocher-Langenbeck approach with In addition to joint instability, joint after injury because of concern that an the Ganz trochanteric fl ip osteotomy incongruity is an indication for surgical earlier surgical procedure would place and the modifi ed Gibson approach.19,20 treatment. Joint incongruity is usually patients at risk for increased blood loss. caused by intra-articular osteochon- However, a recent study has shown that Standard Kocher- dral fracture fragments interdigitated posterior wall fractures might be a sub- Langenbeck Approach between the femoral head and the ac- set of acetabular fractures that can be The standard Kocher-Langenbeck etabular articular surface, which result treated immediately without increased approach (Figures 11 and 12) may be in residual subluxation of the hip joint. risk of excessive blood loss.18 Indica- performed with the patient either in a Although usually obvious on plain tions for emergent surgery include a lateral position with a pelvic stabilizer radiographs, two-dimensional CT hip dislocation that is irreducible by and the leg draped free or in the prone provides better visualization. When closed means, a hip dislocation after position. The prone position may be hip stability is in doubt, skeletal trac- reduction that is unstable with traction, used in combination with a special- tion is recommended, pending further a posterior wall fracture with an associ- ized acetabular fracture table, which evaluation. Unstable hips often require ated femoral neck fracture, and an open facilitates distraction of the hip joint skeletal traction after reduction. Pre- posterior wall fracture. and allows for hip fl exion by control operative skeletal traction will prevent It is uncommon to select nonsurgical of a leg spar. A universal distractor is a recurrent dislocation, as well as femoral treatment for a patient with surgical in- useful alternative to a specialized table head articular wear from incarcerated dications. However, this option should (Figure 13).

Figure 10 A, AP pelvic radiograph of a patient with a left superior extended posterior wall acetabular fracture showing involvement of the radiographic roof, indicating the superior nature of the fracture. B, Representative CT images from superior (left) to inferior (right) of the left extended posterior wall fracture showing extension nearly to the anterior inferior iliac spine. C, Intraoperative anatomy of the left superior wall acetabular fracture with the gluteus medius muscle retracted. For orientation, superior is on the right and lateral is on the bottom of the photograph. Note the disruption of the gluteus minimus muscle (white arrows), a portion of which underlies the piriformis tendon, caused by the displacement of the posterior wall fracture. Visualization and fi xation of this fracture would be diffi cult with a standard Kocher-Langenbeck approach. A modifi ed Gibson approach or a trochanteric fl ip osteotomy is advised. (Adapted with permission from Kregor PJ, Stover M: Acetabular fractures, in Stannard JP, Schmidt AH, Kregor PJ, eds: Surgical Treatment of Orthopaedic Trauma. New York, NY, Thieme, 2007, pp 471-521.)

A typical belief is that the Kocher- short external rotators is usually dis- As in all surgical approaches, a reg- Langenbeck approach for a posterior torted by a posterior wall fracture. Fur- imented and logical sequence for the wall fracture of the acetabulum is iden- thermore, joint capsule integrity must Kocher-Langenbeck approach should tical to that for THA. However, there be maintained because it is usually the be followed to prepare for fi xation of are many critical differences. Mainte- sole surviving soft-tissue attachment a posterior wall fracture of the acetab- nance of the blood supply from the as- to the posterior wall fragment, yet it ulum. The steps of the approach are cending branch of the medial femoral is sometimes sacrifi ced in THA. The as follows: (1) The skin incision begins circumfl ex artery is paramount in ace- sciatic nerve is identifi ed and protected proximally, approximately 5 cm from tabular fracture surgery but is sacrifi ced during posterior wall acetabular frac- the posterior iliac crest, and has an apex in THA.21 In addition, the normal anat- ture surgery, whereas it is avoided and at the greater trochanter. The distal in- omy of the gluteus minimus and the left undisturbed during THA. cision continues approximately 15 to

Figure 12 Illustration showing the Kocher-Langenbeck approach ﬁ nal exposure of the retroacetabular surface. (Adapted from Matta JM, Letournel E, Browner BD: Surgical management of acetabular fractures. Instr Course Lect 1986;35:382-397.)

the surgical procedure. (7) The interval Figure 11 Kocher-Langenbeck and modifi ed Gibson incisions. The greater trochanter is outlined by black dashes (D). Angle ADE shows the location between the quadratus femoris and the of the Kocher-Langenbeck skin incision superimposed on the gluteal fascia. obturator internus should be developed, Angle BDE shows the location of Gibson’s original skin incision superimposed with its attached superior and inferi- on the gluteal fascia. The straight line (CDE) shows the current skin incision for the modifi ed Gibson approach. (Copyright Berton R. Moed, MD, St. Louis, or gemelli muscles (also known as the MO.) triceps coxae muscle). The quadratus femoris should be maintained because it 20 cm along the midlateral aspect of with the muscle fi bers. (5) The gluteus protects the blood supply of the femoral the femur. (2) Skin fl aps should not be maximus is released 1.0 to 1.5 cm from head. (8) The obturator internus tendon created between the subcutaneous fat its insertion on the posterolateral bor- and the piriformis tendon are released and the fascia. (3) The iliotibial band is der of the femur. Deep to this tendon, 1.5 cm from their attachments on the incised distally and split up to the level approximately 1.0 to 1.5 cm from the greater trochanter. Releasing the ten- of the greater trochanter. A common cephalad border, is a branch of the fi rst don too close to the greater trochanter mistake is to make this incision too perforator. Anticipation and coagula- will jeopardize the blood supply of the posterior, because this would misalign tion of this vessel will minimize blood femoral head. (9) The interval between the subsequent split in the gluteus max- loss during tendon release. Although the the capsule, the piriformis, and the ob- imus and limit the anterior extent of tendon of the gluteus maximus does not turator internus are developed while the surgical exposure. In addition, it is need to be released in all cases, release maintaining the integrity of the capsule. important to ensure it is not too close does allow better posterior fl ap mobi- (10) The gluteus minimus is elevated to the insertion of the gluteus maximus. lization. (6) The sciatic nerve should off the posterior wall and the superior (4) The gluteus maximus is split be- be visualized on the posterior surface acetabular area. Any devitalized mus- tween the anterosuperior one-third and of the quadratus femoris (Figure 14) cle is débrided. (11) A design-specifi c the posteroinferior two-thirds in line and protected through the remainder of sciatic nerve retractor is placed with its

to the anterior portion of the gluteus maximus muscle. However, exposure relative to the Kocher-Langenbeck approach may be limited for a fracture that requires access to the entire greater sciatic notch, which is unusual for fractures of the posterior wall. Similar to the Kocher-Langenbeck approach, the modifi ed Gibson approach may be performed with the patient positioned either prone or lateral. Moed20 described a straight incision 20 to 30 cm midlateral on the thigh (Fig- ure 11). It is important to know that the gluteus maximus muscle inserts onto the iliotibial band anterior to the anterior border of the greater trochanter in young, muscular patients. In elderly patients, this is more posterior. Branches of the inferior gluteal artery that perfo- Figure 13 Intraoperative photograph of distraction of the hip joint with aid of the universal femoral distractor. One 6.0- or 5.0-mm Schanz screw is placed rate the fascia lata and continue to the in the sciatic buttress, and another is placed in the proximal femur at the level subcutaneous tissue identify the anteri- of the lesser trochanter. For orientation, superior is on the right and lateral is or border of the gluteus maximus. The on the bottom of the photograph. (Reproduced with permission from Kregor PJ, Stover M: Acetabular fractures, in Stannard JP, Schmidt AH, Kregor PJ, fascial cuff around the gluteus maximus eds: Surgical Treatment of Orthopaedic Trauma. New York, NY, Thieme, 2007, is incised and maintained for later clo- pp 471-521.) sure. The gluteus maximus is retracted in a posterolateral direction and aided tip in the lesser sciatic notch, and the Modified Gibson Approach by releasing the insertion of the gluteus obturator internus muscle belly is used In the setting of an extended superior maximus from the posterolateral aspect to cushion the nerve from the retractor. posterior wall fracture of the acetabu- of the femur. Anterior retraction of the Care must be taken to ensure that the lum that reaches beyond the 12-o’clock gluteus medius facilitates anterosuperi- cephalad and caudal edges of the retrac- position anteriorly, visualization and re- or access of the posterior wall. Release tor (where the nerve is not cushioned) duction of the posterior wall fracture of the piriformis and the obturator in- do not impinge on the nerve. (12) The are limited by the gluteus medius mus- ternus is the same as for the standard fracture edges are débrided and may be cle belly and the superior gluteal nerve Kocher-Langenbeck approach. aided by a small curet, a scalpel blade, and vessels. In this case, for added su- and a suction tip. perior or anterior exposure, the mod- Ganz Trochanteric After appropriate reduction and ifi ed Gibson approach as described by Flip Osteotomy fi xation of the posterior wall fracture, Moed20 is benefi cial. It relies on an in- The Ganz trochanteric fl ip osteotomy the wounds are irrigated, and the ten- terval anterior to the gluteus maximus, may have some limited use in extend- dons of the gluteus maximus, the piri- rather than through the muscle belly. In ed posterior wall fractures, in posterior formis, and the obturator internus are that regard, it also may be considered wall fractures associated with femoral repaired. After closure of the iliotibial more muscle sparing. It also has the po- head fractures (Pipkin type IV inju- band, the subcutaneous tissues and skin tential to provide otherwise equivalent ries), and when a surgical dislocation are closed. inferior and posterior access while min- of the femoral head (and intra-articular imizing risk to the neurovascular supply visualization) is desired.19 This surgical

Figure 15 The trochanteric fl ip osteotomy using a Kocher- Langenbeck approach. Exposure of the supra-acetabular area Figure 14 Intraoperative view of the relationship of the sciatic nerve to the after anterior retraction of the quadratus femoris muscle, the obturator internus with attached superior and osteotomized trochanter showing inferior gemelli muscles (also known as the triceps coxae muscle), and the the trigastric attachments of the piriformis muscle. For orientation, superior is on the right and lateral is on the gluteus medius and minimus bottom of the photograph. The sciatic nerve is best found on the posterior muscles attached proximally border of the quadratus femoris muscle. It runs posterior to the conjoint and the vastus lateralis muscle tendon and in most cases anterior to the piriformis muscle belly. (Reproduced attached distally. (Adapted with with permission from Kregor PJ, Stover M: Acetabular fractures, in Stannard permission from Moed BR, Reilly JP, Schmidt AH, Kregor PJ, eds: Surgical Treatment of Orthopaedic Trauma. M: Fractures of the acetabulum, in New York, NY, Thieme, 2007, pp 471-521.) JD Heckman et al, eds: Rockwood and Green’s Fractures in Adults, ed 7. Philadelphia, PA, Lippincott approach is performed with the patient tendon insertions of the piriformis and Williams & Wilkins, 2009, pp 1463- in the lateral position with the ipsilateral the obturator internus) with the gluteus 1523.) leg draped free. Classically, the gluteus medius and minimus muscles attached maximus is split as in the Kocher-Lan- proximally and the vastus lateralis posterior wall fractures. In some cases, genbeck approach, but it also may be muscle attached distally (Figure 15). it may be desirable to make a Z inci- performed using the modifi ed Gibson The piriformis tendon and the obtura- sion in the hip capsule to allow surgical interval (anterior to the muscle belly of tor internus tendon (with its attached dislocation of the femoral head. When the gluteus maximus). The insertions of superior and inferior gemelli muscles) this capsulotomy is performed, it is the piriformis and the obturator inter- may then be released 1.5 cm from their important to maintain the capsular at- nus are left intact before osteotomizing insertions. A key to the approach is the tachments to the posterior wall fracture the greater trochanter to protect the as- posterior-to-anterior sharp elevation of fragments, thereby maintaining their cending branch of the medial femoral the gluteus minimus from the supra-ac- blood supply. Dislocation of the femo- circumfl ex artery. The vastus lateralis etabular region of the ilium. The leg can ral head then can be accomplished by a is elevated proximally in the area of the then be fl exed, adducted, and externally combination of hip fl exion, adduction, vastus lateralis ridge. The major com- rotated to allow access to the anterior and external rotation. In this way, in- ponent of the approach is based on a inferior iliac spine. Therefore, without tra-articular visualization or treatment 1.5-cm thick osteotomy of the great- surgical dislocation of the femoral head, of an associated femoral head fracture er trochanter (made superfi cial to the excellent exposure can be obtained for can be facilitated.

Surgical Reduction and allow visualization and débridement Fixation Methods of these fragments with their articu- As discussed previously, the patient lar surface and the hip joint itself. The can be positioned either prone or lat- subsequent removal of free osteochon- eral on an orthopaedic fracture table or dral fragments and débridement of the a standard radiolucent operating table. hip joint is accomplished by distracting Regardless of the patient position or the femoral head (Figure 13), which the operating table used, it is impor- can be accomplished by using traction tant that adequate intraoperative fl uoro- applied from the fracture table, from a scopic imaging of the acetabulum can universal distractor, or manually with be obtained during the surgical proce- a Schanz screw temporarily placed into dure. The C-arm image intensifi er used the proximal femur. for intraoperative fl uoroscopic imaging The retrieval of large osteochondral Figure 16 Intraoperative photograph showing the femoral is placed on the side opposite the pri- fragments may be diffi cult. Often, suf- head (f) and an impacted and mary surgeon. The hip should remain fi cient hip joint access for this purpose slightly comminuted articular extended and the knee fl exed through- can be obtained by time-limited posi- surface with the underlying compressed cancellous bone (c). out the procedure to reduce tension and tioning of the hip in fl exion (with the (Copyright Berton R. Moed, MD, risk of injury to the sciatic nerve. If hip knee still fl exed) combined with strong St. Louis, MO.) fl exion is required to gain intra-articu- in-line traction. Infrequently, temporary lar access for loose body removal and hip joint redislocation may be needed. capsular hinge is usually at the anterior joint débridement, this position should Hip joint redislocation can provide in- aspect of the wall fragment. Usually, a be maintained for very short periods creased digital or instrument access. long right-angle clamp can be advanced (less than 5 or 10 minutes). In the prone Unfortunately, direct visual access is anteriorly to the point of the capsular position, a femoral transcondylar pin often impaired. The number and the attachment, and the retained wall frag- attached to the fracture table facilitates size of intra-articular fragments deter- ment then can be teased from the joint. control of hip and knee position, as well mined preoperatively from the CT scan If this maneuver is unsuccessful, a tro- as traction force, to minimize iatrogenic are used to ensure adequate removal. As chanteric fl ip osteotomy may be needed sciatic nerve injury. With the patient lat- they are removed, the position and the to safely access this fragment to extract eral, the surgeon must remain attentive orientation of the free osteochondral it from the joint with its capsular attach- to the position of the leg throughout fragments should be noted. This infor- ments intact. the procedure. mation will help the surgeon in the lat- The reduction of the femoral head After the surgical approach is com- er repositioning of each fragment. The into the intact anterior acetabulum is pleted, exposing the posterior wall ligamentum teres is sharply débrided then visually and fl uoroscopically ver- and column, the posterior wall frac- from the cotyloid fossa, and the joint is ifi ed. After the position of the femoral ture fragments then must be carefully thoroughly irrigated to ensure that all head is determined to be correct, the delineated and cleared of debris. The debris has been removed. Otherwise, femoral head is used as a template for surgeon must be cognizant of the the torn ligamentum teres may become reducing the free osteochondral artic- capsular blood supply to the articular interposed between the femoral head ular fragments and marginal impac- fragments. Limiting periosteal elevation and the intact acetabulum. The result- tion (Figure 16). Impacted fragments to the fracture site as much as possi- ing incongruency can adversely affect should be mobilized with underlying ble helps avoid further devasculariza- the subsequent reduction of the pos- cancellous bone, reduced against the tion. Under no circumstances should terior wall fragments. If a fragment of head, and held provisionally in place. any wall fragment containing articular the posterior wall is incarcerated in the Free osteochondral fragments are like- cartilage be released from its capsular joint with intact capsular attachments, wise reduced against the head and held attachment. Rotating the fragments these attachments should not be sac- provisionally in place. Any remaining on their capsulolabral attachments will rifi ced to retrieve the fragment. The underlying bony defect is fi lled with

structural graft. Bone graft is most provisionally hold them in place with reduction is confi rmed by direct visuali- often easily obtained from a window 1.6-mm Kirschner wires (Figure 17) zation of the reduction on the retro- in the greater trochanter, but syn- and follow with defi nitive fi xation us- acetabular surface (Figure 18). Each thetic bone-void fi llers or cancellous ing subchondral miniscrews or bioab- posterior wall fragment may then be allograft also may be used for this pur- sorbable pegs.23 The overlying posterior fi xed with a standard lag screw tech- pose.5,11,22 Although the repositioned wall fragments are then reduced with nique. Smaller fragments may require fragments may be held in place by frac- a straight ball-spiked pusher, and the 2.4- or 2.7-mm screws. All screws ture interdigitation alone, it is best to placed close to the posterior rim must be confi rmed to be extra-articular with C-arm visualization directly along the long axis of the screw or tangential to the screw24 (Figure 19). This should be performed before buttress plate fi x- ation, which may obscure radiographic visualization. Very small rim fragments may require the use of a spring plate. Because lag screws rarely can be inserted perpendicular to the fracture, exces- Figure 18 Intraoperative sive screw tightening will displace the photograph showing the posterior wall fragments. The lag screws must be wall fragments sequentially reduced supplemented with a buttress plate that and held with the straight ball- Figure 17 Intraoperative spiked pusher. Next, lag screws spans the posterior wall fragments from photograph after elevation and are inserted while the ball spike the ischium to the intact ilium. After temporary Kirschner wire fi xation maintains the reduction, thus plate application, the lag screws in the of the impacted intra-articular eliminating the need for temporary fragments. The residual underlying Kirschner wire fi xation. The wall can be fully tightened. cancellous bone defect has been accuracy of the reduction of the Contouring of the buttress plate fi lled with freeze-dried cancellous articular surface is inferred from must be performed with great care. allograft bone. The Kirschner wires the reduction along the acetabular were subsequently exchanged for rim and that of the extra-articular Slight undercontouring of the plate is bioabsorbable pegs. (Copyright cortical fracture lines. (Copyright preferred, which will result in compres- Berton R. Moed, MD, St. Louis, Berton R. Moed, MD, St. Louis, sion of the posterior wall as the screws MO.) MO.)

Figure 19 Examples of intraoperative fl uoroscopic axial (A) and tangential (B) views showing extra-articular positioning of each lag screw after fi xation of a posterior wall fragment. C, A screw shown to be compromising the articular surface—or too close to defi nitively be extra-articular—should be repositioned.

Figure 20 An inappropriately contoured plate loses contact with the posterior wall fragment and is unable to adequately buttress the fragment. placed through the plate are tightened. However, an excessively undercon- toured plate will crush the posterior wall or cause the wall fragments to displace Figure 22 Illustration showing and prevent the femoral head from fully Figure 21 Schematic image a typical posterior wall fi xation seating within the acetabulum. An over- showing the approximate positions construct. (Copyright Berton R. of the superior gluteal nerve (white Moed, MD, St. Louis, MO.) contoured plate will leave a gap between line), artery (gray line) and vein the posterior wall and the plate, result- (black line) are shown. Plates ing in a failure to buttress the fracture positioned above the angle of Evaluation and Treatment the greater sciatic notch may put plus an attendant risk of loss of reduc- the neurovascular bundle at risk of Associated Injuries tion (Figure 20). The buttress plate is for injury during screw insertion. Posterior wall fractures can occur in best placed parallel and close to the rim Plates positioned too medial will not isolation. However, it takes substantial buttress the wall fragments. of the acetabulum, where it can provide force to break the acetabulum, even the most effective buttress for the wall in an elderly patient. As such, poste- fragments. A minimum of two screws is suffi cient (Figure 22). However, rior wall fractures are often associated above and two screws below the pos- in cases of multifragmented posterior with other systemic injuries, and these terior wall fragments anchor the plate wall fractures or those with extensive patients should be evaluated as poten- to the ilium and the ischium, respec- retroacetabular comminution, multiple tially multiply injured using standard tively. Positioning the buttress plate too plates may be required to buttress all Advanced Trauma Life Support pro- medially (away from the rim) provides of the critical fragments (Figure 23). tocols. In addition to systemic injuries, poor stabilization of the posterior wall After plate application, intraopera- these patients often have localized fragments and may result in loss of re- tive fl uoroscopy allows the surgeon to associated injuries that directly affect duction (Figure 21). Plates that are not confi rm the reduction of the posterior fracture management. contoured parallel to the rim of the ac- wall by visualizing both the retroace- As previously noted, posterior wall etabulum and extend posterosuperiorly tabular ilium and the congruity of the fractures usually result from an axial above the level of the top of the greater acetabular articular surface with the force along a fl exed femur. Therefore, sciatic notch should be avoided. Placing femoral head. The hip should be con- injuries to the ipsilateral knee or else- screws into a plate in this location may centrically reduced on AP, obturator where along the line of applied force are put the superior gluteal nerve, artery, oblique, and iliac oblique fl uoroscopic common.25 The exact nature and the and vein at risk of excessive stretch or views (Figure 23). All screws should incidence of these injuries are not well direct injury (Figure 21). Typically, a be confi rmed to be in an extra-articular documented in the literature. Further- single, well-contoured buttress plate location and of appropriate length. more, these injuries often are occult.

Figure 23 AP (A), obturator oblique (B), and iliac oblique (C) ﬂ uoroscopic views demonstrate the use of a supplemental plate, show congruency between the femoral head and the acetabulum, and document the appropriate location and length of the implants.

the same anesthesia as the acetabular fl uid was culture-positive in 46% of the fracture surgery. To decrease tension 24 patients, despite being a closed injury. on the sciatic nerve, the ipsilateral knee In all cases, the lesions were débrided should be maintained in approximately extensively either before or during sur- 90° of fl exion during acetabular frac- gery. An infection developed in three ture surgery. This knee position will patients, but only one of these three stress the fi xation of a newly repaired had been culture-positive at the time patellar fracture. Therefore, the acetab- of the initial débridement. Tseng and ular fracture is usually addressed before Tornetta 28 reported on a percutaneous Figure 24 Clinical photograph fi xation of the patellar fracture. method in a small number of patients, of a Morel-Lavallee lesion in a The Morel-Lavallee lesion (Fig- using a plastic brush and pulsed lavage patient with combined pelvic and ure 24) occurs when the skin and sub- to débride the injured adipose tissue. A acetabular fractures. (Copyright Berton R. Moed, MD, St. Louis, cutaneous tissue are sheared from the closed-suction drain was placed within MO.) underlying fascia over the trochanteric the lesion and then removed when the region. This closed, degloving, soft- drainage was less than 30 mL during a Therefore, the knee must be carefully tissue injury creates a potential space 24-hour period. Fracture fi xation was evaluated for instability, especially in- fi lled with hematoma and liquefi ed fat. deferred until at least 24 hours after volving the posterior cruciate ligament. It may be recognized by a fl uid wave on drain removal. Infections were avoided Often, this examination is diffi cult or palpation or later identifi ed by the pres- by using this technique. limited because of patient discomfort.26 ence of a fl uctuant, circumscribed area Although both of these series were Consequently, the knee should under- of cutaneous anesthesia and ecchymosis. small, it is reasonable to assume that a go a thorough examination with the Morel-Lavallee lesions are more com- surgical procedure through damaged patient under anesthesia at the conclu- mon with acetabular fractures resulting tissue will increase the risk of wound sion of any required hip surgery. Liga- from lateral impact. However, these le- problems and infection, and it appears mentous injuries are usually addressed sions can occur with a poste rior wall that management should change de- at a later time; however, fractures of fracture, and it is an important factor in pending on the severity of the lesion. the patella often are repaired during surgical planning. Hak et al27 found this For small lesions with little visible

damage to the skin, débridement and Usually, direct packing of the injured may be at risk. However, the muscles irrigation of the lesion should suffi ce vessel is all that is required. The pack- innervated by these nerves are diffi cult as the fi rst stage of acetabular fracture ing should be left undisturbed for 20 to if not impossible to evaluate in the acute surgery before proceeding deep to the 30 minutes. In the rare instance in injury stage. fascia. The incision for débridement which the bleeding does not stop, it is Approximately 7% of posterior dis- should incorporate the vertical limb of best to close the wound and proceed locations of the hip have an associated the standard surgical approach. At the with angiographic embolization. fracture of the femoral head.31 ORIF end of the procedure, wound closure In contradistinction to arterial inju- of both fractures is generally accept- can proceed normally, and what should ries, associated nerve injuries are quite ed as the best treatment option for a be a relatively small and localized area common. Traumatic injury of an ipsi- displaced acetabular fracture associ- of dead space can be managed with lateral peripheral nerve occurs in more ated with a femoral head (Pipkin type closed-suction drainage. For more se- than 10% of patients.5,13 Nerve injury is IV) injury.32 When the primary pathol- vere lesions with an area of impaired usually caused by stretching related to ogy is the femoral head fracture (the skin, following the débridement as just the associated hip dislocation; however, posterior wall fracture does not have described and after subsequent acetab- direct laceration or crush of the sciatic surgical indications), the anterior Smith- ular fracture fi xation, the deep fascia nerve by displaced fracture fragments Petersen approach is preferred.32,33 His- should be closed, but the skin and sub- also can occur. Given the direction of torical concerns of an increased risk of cutaneous tissue should be left open for the injuring force, the sciatic nerve is at osteonecrosis of the femoral head by wound management and secondary clo- greatest risk. Sciatic nerve injury is most performing an anterior capsulotomy in sure. With a severe lesion, débridement common and is usually partial in nature, the presence of a torn posterior capsule is performed as a separate procedure, mainly involving the peroneal division. have been shown to be unfounded.32,33 and the acetabular surgery is delayed Therefore, it is important to carefully However, this anterior approach has pending soft-tissue recovery. document the function of the sciatic been associated with an increased risk Although associated injuries to ma- nerve before surgery. The prognosis for of heterotopic ossifi cation.32 jor vessels are extremely rare, injury of functional recovery of a sciatic nerve The presence of a posterior wall frac- the superior gluteal artery can occur. injury is variable, depending on the ture with surgical indications mandates The injuring force is directed toward degree of involvement of the peroneal a posterior approach to fi x the wall frac- the superior gluteal artery, especially division. Complete or nearly complete ture. Although the Kocher-Langenbeck in the case of superior posterior wall recovery of an injured tibial division can approach provides excellent visuali- fractures. The true incidence of this be expected; however, a severely injured zation of the posterior wall, the intact injury is unknown because the injured peroneal division cannot be expected to femoral head blocks access to the fem- artery usually becomes occluded by recover good function.29 oral head fragments, which commonly clotted blood before surgical interven- Other peripheral nerves, such as the originate from the anterior aspect of tion. Nonetheless, bleeding from the femoral, obturator, and superior gluteal the head. One option is to perform two superior gluteal artery will occasionally nerves, also may be injured. Gruson and approaches: the anterior Smith-Petersen be encountered at the time of surgery. Moed30 documented 4 femoral nerve in- approach to address the head fracture Whether the bleeding is the result of juries in 726 acetabular fractures treated followed by the Kocher-Langenbeck iatrogenic surgical damage or clot dis- surgically. In two patients, the injury approach for the posterior wall.32 A ruption in a previously injured vessel was caused by the trauma, and two in- more recent and better option is to use is immaterial. Whatever the cause, the juries were iatrogenic. One of the trau- a Ganz trochanteric fl ip osteotomy with bleeding can be substantial and must be matic nerve injuries was associated with surgical dislocation of the hip, as pre- quickly controlled. However, the sur- a posterior wall fracture. At an average viously described.19,34,35 This approach geon should avoid direct clamping of of 10 months, all patients had recovered provides excellent visualization of the the vessel. Attempts at direct clamping grades 4 to 5 motor strength. The loca- femoral head fragment and the poste- often are unsuccessful and usually cause tion of the superior gluteal nerve puts rior wall without any additive risk to the damage to the superior gluteal nerve. it at risk, and the obturator nerve also blood supply of the femoral head.21,35

When a femoral neck fracture oc- comfortable with acetabular fracture transfusion, fracture malreduction, curs in association with a posterior surgery, it is best to stabilize the femur and implant malposition. Deep vein wall fracture, the best approach is to and leave the acetabulum for later re- thrombosis can occur any time after consider the two fractures as separate construction. If this is the situation and the injury. Late complications include entities, providing optimal treatment the hip is dislocated, closed hip reduc- heterotopic ossifi cation, osteonecrosis of each. The femoral neck in a young tion techniques are often unsuccessful of the femoral head, traumatic hip joint adult should be treated fi rst in an urgent or are not even possible. Rather than arthritis, and patient dysfunction. fashion, generally using a Watson-Jones performing an open reduction of the approach.25 The acetabular fracture dislocation, the hip can usually be re- Early Complications can be addressed with a separate, pos- duced using a percutaneous technique.37 Letournel and Judet5 reported a de- terior approach during the same anes- Using fl uoroscopy, a Schanz screw can creasing rate of iatrogenic nerve injury thesia or at a later time, as the situation be inserted into the proximal femoral with increasing surgical experience. In dictates. If planned in advance, the fragment through a small stab wound. the hands of surgeons experienced with Watson-Jones approach can be placed Using manual traction applied with a acetabular fracture, iatrogenic nerve so as not to compromise a subsequent T-handle chuck applied to the end of injury ranges from 1% to 3% in large Kocher-Langenbeck approach. Howev- the screw, the dislocation is reduced. series encompassing all acetabular frac- er, if necessary, the inferior limb of the The screw is then removed, the stab ture types.5,40 In large series reporting Watson-Jones approach can be incor- wound closed, and the limb maintained on only fractures of the posterior wall, porated into the Kocher-Langenbeck in traction until defi nitive surgery can the rate was lower—less than 1%.11,13,41 approach. This combination of injuries be performed. Intraoperative nerve monitoring has in an older adult is rare, and treatment The gold standard for the treat- not been shown to improve on these is controversial; therefore, care must ment of a femoral shaft fracture is a already more than satisfactory results. be individualized. However, address- reamed antegrade intramedullary nail. Furthermore, a study showed that nerve ing both injuries by performing THA However, there is a concern that a monitoring is of questionable value for as the primary treatment should be Kocher-Langenbeck approach for ac- posterior wall fracture surgery, even considered.36 etabular fracture fi xation in conjunc- when performed by less experienced In general, for fractures of the prox- tion with antegrade nailing, either as a surgeons.42 imal femur associated with a posterior staged or a sequential procedure, will Injury to the gluteal nerves also wall fracture of the acetabulum, both result in a higher complication rate than may occur, especially if a Kocher- fractures are treated using the posterior if an alternative method of femoral frac- Langenbeck approach is used. The approach.25 A posterior wall fracture in ture fi xation is selected.25,38 This issue proximal extent of the approach association with an ipsilateral femoral has not been well studied. However, through the gluteus maximus is to the shaft fracture is a relatively infrequent in a small series of 13 patients, Bishop fi rst crossing nerve branch of the infe- and challenging situation. Usually, et al38 reported that this approach was rior gluteal nerve, which innervates the these are high-energy injuries. There not associated with excessive rates of muscle (Figure 25). Traction in this are multiple options for managing this wound-healing complications, but the area or further extension of the inci- combination of injuries, but stabilizing occurrence of heterotopic ossifi cation sion will denervate the anterosuperior the femur is the main priority for gen- increased. Therefore, retrograde nailing portion of this muscle.5,43 Excessive re- eral patient treatment. If the patient is of the femoral shaft currently appears traction of the gluteus minimus muscle stable and the surgeon is comfortable to be the better option.25,39 and/or elevation near the greater sciat- with the acetabular fracture surgery, ic notch can result in superior gluteal both injuries can be managed during Outcomes and Postoperative nerve dysfunction. Delay in the return the same anesthesia. However, if the Considerations of normal hip abductor muscle func- combined surgery may cause exces- Important early complications con- tion has been reported after using the sive physiologic stress to an already sist of nerve injury, infection, injury Kocher- Langenbeck approach.44,45 Al- injured patient, or the surgeon is not to blood vessels, bleeding requiring though the reasons for this dysfunction

Figure 25 A, Intraoperative photograph showing the gluteus maximus muscle fi bers split to the fi rst nerve branch. A self-retaining retractor holds the gluteus maximus muscle fi bers apart. The nerve (located at the tip of the scissors) is crossing the split in the gluteus maximus muscle fi bers from posterior to anterior in the surgical fi eld. (Copyright Berton R. Moed, MD, St. Louis, MO.) B, Companion drawing to clarify the exposure. (Reproduced with permission from Moed BR: Acetabular fractures: Kocher-Langenbeck approach, in Wiss DA, ed: Master Techniques in Orthopaedic Surgery: Fractures, ed 3. Philadelphia, PA, Lippincott Williams & Wilkins, 2012, pp 817-884.) may be multifactorial, one possible wall fracture to require more than the two-dimensional CT is better at deter- explanation is iatrogenic injury to the equivalent of two units of blood during mining reduction after posterior wall superior gluteal nerve. As noted previ- or after surgery.11 If this occurs, other fracture surgery, and residual irregulari- ously, iatrogenic traction injury to the sources of bleeding should be sought. ties at the articular surface can partially femoral nerve is rare but does occur.30 As previously noted, injury to the supe- explain the differences between postop- Recovery of nerve function can be rior gluteal artery can occur, from either erative plain radiographic assessment expected. iatrogenic laceration or clot disruption. and subsequent radiographic and clin- Deep infection after posterior wall Early surgical treatment of posterior ical outcomes. The outcome of the joint fracture surgery is uncommon, with wall fractures is not associated with is defi nitely at risk with an inadequate reports ranging from zero to 1%.4-6 increased blood loss.18 reduction (≥ 10-mm gap) or residual hip However, deep infection is a devas- The goal of posterior wall recon- instability. Revision of posterior wall tating complication, resulting in joint struction is an anatomic restoration of fractures is associated with fair to poor destruction in up to 50% of patients.5,11 the joint surface and a stable, congru- results in more than 50% of patients.49,50 Although surgeon experience will de- ent hip. In large case series, as judged Because of the anatomy of the ret- crease the infection rate,5 infection risk by plain radiographs, anatomic reduc- roacetabular surface, screws inserted increases with increasing body mass in- tion of posterior wall fractures has along the acetabular rim and in certain dex of the patient.46,47 As noted previ- been reported in the range of 93.7% to positions on the retroacetabular sur- ously, surgery through a compromised 97.0%.5,11,40 Despite the apparent ana- face place the joint surface at risk for soft-tissue envelope (such as a Mo- tomic reduction, there was no direct intra-articular penetration. Although rel-Lavallee lesion) poses an increased correlation with radiographic or clinical techniques for the safe placement of infection risk. A high body mass index results. This situation could be caused screws have been described, using in- (≥ 30), intensive care unit stay, and the by several associated factors, including traoperative fl uoroscopy, as described presence of a Morel- Lavallee lesion all cartilaginous injury to the acetabular previously, is the best method.5,24,51 have been shown to be independent or femoral joint surfaces. Another ex- Using postoperative, two-dimension- risk factors for infection in acetabular planation is that plain radiographs are al CT has no added benefi t in this re- fracture surgery.46,48 It is uncommon inadequate for evaluating articular regard.24 Furthermore, any information for a patient with an isolated posterior duction.5,11 Moed et al11,13 reported that provided by postoperative CT would

Late Complications The presence and the importance of heterotopic ossifi cation is approach de- pendent. After a Kocher-Langenbeck approach, heterotopic ossifi cation resulting in clinically signifi cant loss of hip motion occurs in less than 10% of patients.5,40 Several potential risk factors have been identifi ed, such as male sex, patients with head injuries, Figure 26 Postoperative CT can be used before the routine use of and prolonged mechanical ventilation. intraoperative fl uoroscopy to assess screw position. Postoperative CT section after the fracture surgery showing intra-articular screw placement (A) and Options for treatment include using after revision surgery for screw repositioning (B). (Copyright Berton R. Moed, perioperative prophylactic agents (for MD, St. Louis, MO.) example, indomethacin and irradiation) and/or delayed excision of any heterotopic ossifi cation causing clinical impairment.57 The effi cacy of in- require revision surgery, whereas in- form until the patient is ambulatory. domethacin is subject to debate, and traoperative fl uoroscopy allows cor- Despite the use of prophylactic treat- the advisability of using irradiation in a rection of the problem in real time, ment, the prevalence of posttraumatic young population with less than 10% at during the fracture fi xation surgery and postoperative deep vein thrombosis risk is controversial. Therefore, for pos- (Figure 26). occurs in approximately 11% to 15% of terior wall fractures, delayed excision Venous thromboembolism is a fre- patients, with pulmonary embolism in of any heterotopic ossifi cation causing quent complication in trauma patients. approximately 1% of patients.52,53 Fa- clinical impairment is perhaps the best In acetabular fracture patients, the risk tal pulmonary embolism occurs in less treatment course. of deep vein thrombosis is high, and than 0.5% of patients.52,53 The diagnosis of femoral head osteo- pulmonary embolism occurs in ap- Screening for deep vein thrombosis necrosis after hip fracture-dislocation proximately 1% to 2% of patients.5,52,53 has not been found to be helpful.52,53 can be problematic. This entity must Evidence-based clinical practice guide- Screening is indicated only in those be distinguished from simple damage lines recommend routine perioperative patients who have received inadequate to the femoral head from the fracture chemical and/or mechanical prophy- thromboprophylaxis.53,54 Using an infe- trauma or mechanical wear from poste- laxis.54 However, for major orthopaedic rior vena cava fi lter for thromboprophy- rior wall fracture malreduction.5,11,13 Ex- surgery in patients not at increased risk laxis is not recommended.55 However, perimental studies have shown that the for bleeding, such as a patient with an an inferior vena cava fi lter should be blood supply to the femoral head during isolated posterior wall fracture, dual considered for therapeutic use in pa- posterior hip dislocation is temporari- prophylaxis (chemical and mechanical) tients undergoing surgery in whom ly interrupted by stretching and twist- is indicated.54 Mechanical prophylaxis venous thromboembolism has been ing.58 This may explain the fact that in using only portable, battery-powered diagnosed preoperatively.54 In a report posterior wall fractures, osteonecrosis units capable of recording and report- of 88 patients with pelvic or acetabular of the femoral head is associated with ing proper wear time is recommended, fractures in whom deep vein throm- prolonged dislocation, usually beyond and efforts should be made to ensure bosis developed preoperatively and an 12 hours.11,13,59 An intact obturator ex- 18 hours of daily compliance.54 To be inferior vena cava fi lter was placed, ternus tendon may be protective of the effective, prophylaxis should continue the complication rate was very low.56 femoral head blood supply when the hip for up to 35 days from the day of sur- Postthrombotic syndrome developed is dislocated.21,60 Osteonecrosis of the gery.54 Most acetabular fracture sur- in only one patient, and there were no femoral head after posterior wall frac- geons continue prophylaxis in some recorded recurrent thromboemboli.56 ture surgery is associated with a poor

clinical outcome, usually requiring total limit its usefulness as a method for treatment of acetabular fractures. Instr Course Lect 1999;48:481-496. joint arthroplasty.5,11 evaluating functional outcome in these The best outcomes from the surgi- patients.62 It also has been shown that 7. Moed BR, Dickson KF, Kregor PJ, Reilly MC, Vrahas MS: The surgical cal treatment of posterior wall fractures quality of life after acetabular fracture treatment of acetabular fractures. Instr are predicated on an anatomic reduc- fi xation continually improves during Course Lect 2010;59:481-501. 11,13 tion of the disrupted joint surface. the 2-year postoperative period but re- 8. Judet R, Judet J, Letournel E: Frac- Letournel and Judet5 reported clinical mains lower than norms.63 Anatomic tures of the acetabulum: Classifi cation outcomes after acetabular fractures reduction results in better quality-of-life and surgical approaches for open reduction. Preliminary report. J Bone 63 using the Merle d’Aubigné and Postel outcomes in most dimensions. Joint Surg Am 1964;46:1615-1646. scoring system, which evaluates pain, 9. Brooks RA, Ribbans WJ: Diagnosis ambulation, and range of motion. Mat- Summary and imaging studies of traumatic hip ta40 modifi ed this system by scoring Restoring the congruity and the stability dislocations in the adult. Clin Orthop Relat Res 2000;377:15-23. range of motion relative to the contra- of the hip joint are the goals for treating lateral, uninjured hip. Many subsequent a posterior wall fracture of the acetab- 10. Marsh JL, Slongo TF, Agel J, et al: Fracture and dislocation classifi cation reports have used this modifi ed scoring ulum. In general, a displaced fracture compendium—2007: Orthopaedic system, which evaluates clinical func- will need ORIF. Nonetheless, a substan- Trauma Association classifi cation, tion of the injured hip. In 2002, Moed tial subset of fractures exist that can be database and outcomes commit- 11 tee. J Orthop Trauma 2007;21(10, et al reported 89% good to excellent successfully managed nonsurgically. suppl):S1-S133. clinical results at a mean follow-up of However, a patient with a posterior wall 11. Moed BR, Willson Carr SE, Watson 5 years. These results are similar to the fracture requires a complete evaluation, JT: Results of operative treatment 82% reported by Letournel and Judet5 including a stress examination of the of fractures of the posterior wall of and the 85% reported by Pantazopou- hip joint, before a nonsurgical course of the acetabulum. J Bone Joint Surg Am 2002;84(5):752-758. los et al.61 Tannast et al60 predicted a treatment is selected. Although posterior 12. Baumgaertner MR: Fractures of the 70% survivorship of the hip joint at 20 wall fractures present problems unique posterior wall of the acetabulum. J Am years for posterior wall fractures of the from other acetabular fracture types, Acad Orthop Surg 1999;7(1):54-65. acetabulum. with attention to proper treatment prin- 13. Moed BR, Carr SE, Gruson KI, Wat- Overall patient functional outcomes ciples, good to excellent clinical results son JT, Craig JG: Computed tomo- after posterior wall fractures evaluated can be obtained in most patients. graphic assessment of fractures of the posterior wall of the acetabulum after using the Musculoskeletal Function As- operative treatment. J Bone Joint Surg sessment questionnaire have reported References Am 2003;85(3):512-522. scores signifi cantly worse than norma- 1. Knight RA, Smith H: Central frac- 14. Moed BR, Ajibade DA, Israel H: tive values.62 Mobility and emotional tures of the acetabulum. J Bone Joint Computed tomography as a predictor Surg Am 1958;40(1):1-16. categories were important determinants of hip stability status in posterior wall 2. Rowe CR, Lowell JD: Prognosis of fractures of the acetabulum. J Orthop of the total score. In comparing the fractures of the acetabulum. J Bone Trauma 2009;23(1):7-15. Musculoskeletal Function Assessment Joint Surg Am 1961;43:30-59. 15. Reagan JM, Moed BR: Can com- questionnaire to the modifi ed Merle 3. Stewart MJ: Discussion: Prognosis puted tomography predict hip d’Aubigné scoring, the modifi ed Merle of fractures of the acetabulum. J Bone stability in posterior wall acetabu- d’Aubigné score revealed a ceiling effect, Joint Surg Am 1961;43:59. lar fractures? Clin Orthop Relat Res 2011;469(7):2035-2041. limiting its ability to show differences 4. Stewart MJ, Milford LW: Frac- 16. Davis AT, Moed BR: Can experts in among patients with supposedly better ture-dislocation of the hip: An end-result study. J Bone Joint Surg Am acetabular fracture care determine hip clinical outcomes. The investigators 1954;36(2):315-342. stability after posterior wall fractures concluded that although the modifi ed using plain radiographs and com- 5. Letournel E, Judet R: Fractures of the puted tomography? J Orthop Trauma Merle d’Aubigné score may be useful Acetabulum, ed 2. New York, NY, 2013;27(10):587-591. for evaluating isolated hip function in Springer-Verlag, 1993. 17. Grimshaw CS, Moed BR: Outcomes patients who have been treated for an 6. Templeman DC, Olson S, Moed of posterior wall fractures of the acetabular fracture, its shortcomings BR, Duwelius P, Matta JM: Surgical acetabulum treated nonoperatively

after diagnostic screening with 28. Tseng S, Tornetta P III: Percutaneous 40. Matta JM: Fractures of the acetab- dynamic stress examination un- management of Morel-Lavallee lesions. ulum: Accuracy of reduction and der anesthesia. J Bone Joint Surg Am J Bone Joint Surg Am 2006;88(1):92-96. clinical results in patients managed 2010;92(17):2792-2800. operatively within three weeks 29. Fassler PR, Swiontkowski MF, Kilroy after the injury. J Bone Joint Surg Am 18. Furey AJ, Karp J, O’Toole RV: Does AW, Routt ML Jr: Injury of the 1996;78(11):1632-1645. early fi xation of posterior wall acetab- sciatic nerve associated with ace- ular fractures lead to increased blood tabular fracture. J Bone Joint Surg Am 41. Gänsslen A, Steinke B, Krettek C: In- loss? J Orthop Trauma 2013;27(1):2-5. 1993;75(8):1157-1166. ternal fi xation of acetabular posterior wall fractures. Oper Orthop Traumatol 19. Siebenrock KA, Gautier E, Ziran BH, 30. Gruson KI, Moed BR: Injury of the 2009;21(3):283-295. Ganz R: Trochanteric fl ip osteotomy femoral nerve associated with ace- for cranial extension and muscle pro- tabular fracture. J Bone Joint Surg Am 42. Baumgaertner MR, Wegner D, Booke tection in acetabular fracture fi xation 2003;85(3):428-431. J: SSEP monitoring during pelvic and using a Kocher-Langenbeck approach. acetabular fracture surgery. J Orthop J Orthop Trauma 1998;12(6):387-391. 31. Brumback RJ, Kenzora JE, Levitt LE, Trauma 1994;8(2):127-133. Burgess AR, Poka A: Fractures of the 20. Moed BR: The modifi ed Gibson femoral head. Hip 1987:181-206. 43. Moed BR: Acetabular fractures: posterior surgical approach to Kocher-Langenbeck approach, in the acetabulum. J Orthop Trauma 32. Swiontkowski MF, Thorpe M, Seiler Wiss DA, ed: Master Techniques in 2010;24(5):315-322. JG, Hansen ST: Operative manage- Orthopaedic Surgery: Fractures, ed 3. ment of displaced femoral head frac- Philadelphia, PA, Lippincott Williams 21. Gautier E, Ganz K, Krügel N, Gill tures: Case-matched comparison of & Wilkins, 2012, pp 817-868. T, Ganz R: Anatomy of the medial anterior versus posterior approaches femoral circumfl ex artery and its for Pipkin I and Pipkin II fractures. J 44. Dickinson WH, Duwelius PJ, Colville surgical implications. J Bone Joint Surg Orthop Trauma 1992;6(4):437-442. MR: Muscle strength testing follow- Br 2000;82(5):679-683. ing surgery for acetabular fractures. J 33. Stannard JP, Harris HW, Volgas DA, Orthop Trauma 1993;7(1):39-46. 22. Moed BR, Willson Carr SE, Craig Alonso JE: Functional outcome of JG, Watson JT: Calcium sulfate used patients with femoral head fractures 45. Matta JM, Olson SA: Factors related as bone graft substitute in acetabular associated with hip dislocations. Clin to hip muscle weakness following fracture fi xation. Clin Orthop Relat Res Orthop Relat Res 2000;377:44-56. fi xation of acetabular fractures. Ortho- 2003;410:303-309. pedics 2000;23(3):231-235. 34. Gardner MJ, Suk M, Pearle A, Buly 23. Giannoudis PV, Tzioupis CC, Moed RL, Helfet DL, Lorich DG: Surgical 46. Karunakar MA, Shah SN, Jerabek BR: Two-level reconstruction of dislocation of the hip for fractures S: Body mass index as a predictor of comminuted posterior-wall fractures of the femoral head. J Orthop Trauma complications after operative treat- of the acetabulum. J Bone Joint Surg Br 2005;19(5):334-342. ment of acetabular fractures. J Bone 2007;89(4):503-509. Joint Surg Am 2005;87(7):1498-1502. 35. Siebenrock KA, Gautier E, Woo AK, 24. Carmack DB, Moed BR, McCarroll Ganz R: Surgical dislocation of the 47. Porter SE, Russell GV, Dews RC, Qin K, Freccero D: Accuracy of detecting femoral head for joint debridement Z, Woodall J Jr, Graves ML: Compli- screw penetration of the acetabulum and accurate reduction of fractures cations of acetabular fracture surgery with intraoperative fl uoroscopy and of the acetabulum. J Orthop Trauma in morbidly obese patients. J Orthop computed tomography. J Bone Joint Surg 2002;16(8):543-552. Trauma 2008;22(9):589-594. Am 2001;83(9):1370-1375. 36. Ward AJ, Chesser TJ: The role of 48. Suzuki T, Morgan SJ, Smith WR, 25. Kregor PJ, Templeman D: Associated acute total hip arthroplasty in the Stahel PF, Gillani SA, Hak DJ: injuries complicating the management treatment of acetabular fractures. Postoperative surgical site infection of acetabular fractures: Review and Injury 2010;41(8):777-779. following acetabular fracture fi xation. case studies. Orthop Clin North Am Injury 2010;41(4):396-399. 37. Kuhn KM, Boudreau JA, Watson 2002;33(1):73-95. JT: Rare combination of ipsilateral 49. Mayo KA, Letournel E, Matta JM, 26. Schmidt GL, Sciulli R, Altman GT: acetabular fracture-dislocation and Mast JW, Johnson EE, Martimbeau Knee injury in patients experiencing pertrochanteric fracture. Am J Orthop CL: Surgical revision of malreduced a high-energy traumatic ipsilateral (Belle Mead NJ) 2013;42(8):372-375. acetabular fractures. Clin Orthop Relat hip dislocation. J Bone Joint Surg Am Res 1994;305:47-52. 38. Bishop JA, Cross WW III, Krieg JC, 2005;87(6):1200-1204. Chip Routt ML Jr: Antegrade femoral 50. Dean DB, Moed BR: Late salvage of 27. Hak DJ, Olson SA, Matta JM: Di- nailing in acetabular fractures requir- failed open reduction and internal agnosis and management of closed ing a Kocher-Langenbeck approach. fi xation of posterior wall fractures internal degloving injuries associated Orthopedics 2013;36(9):e1159-e1164. of the acetabulum. J Orthop Trauma with pelvic and acetabular fractures: 2009;23(3):180-185. 39. Moed BR, Watson JT: Retrograde The Morel-Lavallée lesion. J Trauma nailing of the femoral shaft. J Am 1997;42(6):1046-1051. 51. Norris BL, Hahn DH, Bosse MJ, Acad Orthop Surg 1999;7(4):209-216. Kellam JF, Sims SH: Intraoperative

fl uoroscopy to evaluate fracture reduc- evidence-based clinical practice guide- angiographic study. J Orthop Trauma tion and hardware placement during lines. Chest 2012;141(2, suppl):7S-47S. 1996;10(7):447-454. acetabular surgery. J Orthop Trauma 1999;13(6):414-417. 55. Falck-Ytter Y, Francis CW, Johanson 59. Aho AJ, Isberg UK, Katevuo VK: NA, et al: Prevention of VTE in Acetabular posterior wall fracture: 38 52. Borer DS, Starr AJ, Reinert CM, et orthopedic surgery patients: Anti- cases followed for 5 years. Acta Orthop al: The effect of screening for deep thrombotic therapy and prevention of Scand 1986;57(2):101-105. vein thrombosis on the prevalence of thrombosis, 9th ed. American College pulmonary embolism in patients with of Chest Physicians evidence-based 60. Tannast M, Pleus F, Bonel H, Gal- fractures of the pelvis or acetabulum: clinical practice guidelines. Chest loway H, Siebenrock KA, Anderson A review of 973 patients. J Orthop 2012;141(2, suppl):e278S-e325S. SE: Magnetic resonance imaging in Trauma 2005;19(2):92-95. Medline traumatic posterior hip dislocation. J Orthop Trauma 2010;24(12):723-731. 53. Moed BR, Miller JR, Tabaie SA: Se- 56. Toro JB, Gardner MJ, Hierholzer C, et quential duplex ultrasound screening al: Long-term consequences of pelvic 61. Pantazopoulos T, Nicolopoulos for proximal deep venous throm- trauma patients with thromboembolic CS, Babis GC, Theodoropoulos bosis in asymptomatic patients with disease treated with inferior vena ca- T: Surgical treatment of acetabu- acetabular and pelvic fractures treated val fi lters. J Trauma 2008;65(1):25-29. lar posterior wall fractures. Injury operatively. J Trauma Acute Care Surg 1993;24(5):319-323. 2012;72(2):443-447. 57. Moed BR, Israel H: Heterotopic ossifi cation prevention and treat- 62. Moed BR, McMichael JC: Outcomes 54. Guyatt GH, Akl EA, Crowther M, ment: What is the best way to prevent of posterior wall fractures of the Gutterman DD, Schuünemann HJ; heterotopic ossifi cation following acetabulum. J Bone Joint Surg Am American College of Chest Physicians acetabular fracture fi xation? in Wright 2007;89(6):1170-1176. Antithrombotic Therapy and Preven- JG, ed: Evidence-based Orthopaedics. Phil- 63. Borg T, Berg P, Larsson S: Quality tion of Thrombosis Panel: Executive adelphia, PA, Saunders Elsevier, 2009, of life after operative fi xation of summary: Antithrombotic therapy pp 353-359. displaced acetabular fractures. J Orthop and prevention of thrombosis, 9th ed. Trauma 2012;26(8):445-450. American College of Chest Physicians 58. Yue JJ, Wilber JH, Lipuma JP, et al: Posterior hip dislocations: A cadaveric