A surgical approach algorithm for transverse posterior wall fractures aids in reduction quality

Abstract

Background: Transverse posterior wall fractures are difficult to treat and historically have been associated with stiffness, posttraumatic arthritis, and pain, which correlate with the reduction. The Kocher-Langenbeck approach is used most often, whereas the extended iliofemoral approach has been reserved for more complex injury patterns. The latter approach has substantially more risks. No data to our knowledge exist on the use of sequential anterior and posterior approaches for this pattern.

Questions/purposes: The purpose of this study is to evaluate an algorithmic method to determine the choice of surgical approach(es) for transverse posterior wall fractures. The main question is: will this approach-based algorithm allow for adequate reduction and stabilization to union? Our secondary endpoints were Merle d'Aubigne scores, reoperations, and radiographic sequelae including arthritis, avascular necrosis, and heterotopic ossification.

Methods: A retrospective study was conducted in which patients were drawn from an existing database. The inclusion criterion was transverse posterior wall fractures with adequate imaging treated by one surgeon. All but one patient were treated within 2 weeks of injury. Mean followup was 23 months (range, 3 months to 11 years). Between November 5, 1999, and August 22, 2012, 74 patients were treated with open reduction internal fixation for this injury; nine were excluded as a result of percutaneous treatment or inadequate preoperative imaging. The remaining 65 patients (88%) comprised the study group. All patients were treated by the senior surgeon with an algorithm that consisted of either a Kocher-Langenbeck or sequential approach based on the location, magnitude, and direction of displacement of the ischiopubic segment. Indomethacin was prescribed to all patients for heterotopic ossification prophylaxis for a total of 6 weeks postoperatively. Based on the algorithm, 82% (53 patients) were treated with Kocher-Langenbeck and 18% (12 patients) with the sequential approach. Adequacy of reduction was measured using AP and Judet views of the pelvis; union was determined empirically by pain-free weightbearing and lack of displacement over time. Outcomes were the Merle d'Aubigne score and radiographic findings of avascular necrosis or arthrosis.

Results: The algorithm resulted in 100% reduction within 1 mm on plain radiographs. Initial displacement was greater in the patients undergoing the sequential approach (p=0.01, 7.7 versus 12.4 mm). The average d'Aubigne score was 15.3. Radiographic arthritis scores were 68% excellent/good. Avascular necrosis developed in five patients (8%). Five patients (8%) went on to THA, and four patients (6%) developed superficial or deep infection. Only one patient developed Brooker III heterotopic ossification and this was not symptomatic.

Conclusions: This algorithm helps guide appropriate selection of the surgical approach and results in accurate reduction with functional and radiographic results that are comparable with existing series while avoiding extended approaches. However, like any operative decision, the choice of approach should not depend entirely on an algorithm; rather, the algorithm is best used as a guide to understand the factors involved in treating these rare and complex injuries and to help make an appropriate choice for an individual patient.

Level of evidence: Level IV, case series. See the Guidelines for Authors for a complete description of levels of evidence.

Fig. 1

Algorithm for treatment of transverse/posterior wall acetabular fractures. Displacement direction (anterior/posterior/neutral) refers to the sagittal plane translation of the free fragment for the transverse component measured on an axial CT scan at the level of the acetabular roof. Obliquity is measured on AP and Judet radiographs and refers to where the transverse fracture line exits at the columns. For example, if the fracture exits high at the anterior column and low on the posterior column, it is classified as “high anterior”; if exiting at the same level, it is classified as “neutral.” *One patient out of seven was treated with the sequential approach (did not follow algorithm); the patient had sacroiliac joint displacement anteriorly; ^†one patient out of six treated with the sequential approach (did not follow algorithm); the patient had a very high posterior wall fracture and the surgeon worried about correct placement of tines from the back.

Fig. 2A–G

An example of using the algorithm to treat a left transverse + posterior wall fracture in a 41-year-old man. This patient was treated with sequential approaches. (A) AP pelvis radiograph showing transtectal transverse fracture line (arrow, first step of algorithm). (B) Axial injury CT scan showing gapping but no translation in the sagittal plane (arrow). This is classified as neutral displacement in the sagittal plane (second step of algorithm). (C–D) Judet views showing fracture (arrows) exiting high in the anterior column and relatively low in the posterior column. This is classified as “high anterior obliquity” (third step of the algorithm). The large gap and high obliquity of the fracture favor a sequential approach (final step of the algorithm). (E) Intraoperative fluoroscopy showing reduction of the transverse fracture. (F) The final construct for the sequential approach is seen here. The mild symphyseal separation was not addressed because it was aligned after reduction of the transverse fracture. (G) Followup radiograph taken approximately 1 year after injury. The joint space is maintained and the patient had a score of 18 at 3 years.