OTA 2002 Posters

Surgical Treatment Plan for Acetabular Fractures Associated with Pelvic Instability

David C. Ervin, MD; Nabil A. Ebraheim, MD; Fady Sabry, MD; Medical College of Ohio, Toledo, Ohio, USA

Purpose: Acetabular fracture associated with pelvic instability is a complicated injury pattern that is difficult to treat. This combination requires treatment by an experienced surgeon capable of accurate interpretation of different imaging modalities and proper choice and execution of a treatment plan. There is little current information in the literature to suggest a strategy for approaching the patient with anterior or posterior pelvic instability or both with an associated acetabular fracture. Specifically, there is no consensus on the timing or order in which these injuries should be surgically addressed. At our institution, we use a systematic approach to surgical fixation. First, we fix the anterior acetabular component, followed by fixation of anterior pelvic instability during the same operative procedure. Then, we fix the posterior acetabular component. Lastly, we stabilize the posterior pelvic instability. The purpose of this study was to assess the fracture pattern, treatment modalities, complications, and outcomes of patients treated under this plan.

Methods: Fourteen patients were identified who had had at least a 2-year follow-up after open reduction internal fixation of an acetabular fracture and pelvic instability. Patients with isolated pelvic or acetabular fractures were excluded from the study. Anterior pelvic instability was determined to be symphysis disruption of more than 2 cm. Posterior pelvic instability was determined to be sacroiliac joint disruption or dislocation or sacral fracture. The method of fixation was consistent in all cases, depending on the fracture pattern. First, the anterior acetabular component was fixed followed by stabilization of the anterior pelvic disruption. Then, the posterior acetabular component was fixed followed by stabilization of the posterior pelvic disruption. All operations were performed by a single surgeon at the same institution. The inpatient and outpatient charts and radiographs were reviewed retrospectively. Mechanisms of injury, fracture patterns, approaches to fixation, associated injuries, complications, and outcomes were assessed. Standardized acetabular and pelvic scores were obtained to assess outcome.

Results: All patients involved in this study had complicated trauma with a variety of associated injuries, including hip dislocation, sciatic nerve palsy, associated long bone fractures, head injuries, and intraabdominal injuries. The average injury severity score (ISS) was 18. The average follow-up was 3.4 years. Patients required staged surgical approaches for fixation. The results of standardized acetabular scores were 67% excellent, 13% good, 7% fair, and 13% poor. The pelvic scores revealed 71% satisfactory and 29% unsatisfactory results.

Discussion/Conclusions: We achieved acceptable outcomes with use of our treatment plan for fixation of acetabular fractures associated with pelvic instability. The rationale behind this protocol was that acetabular fracture reduction would be very difficult to accomplish if reduction of the pelvis were carried out first. Reduction of the anterior acetabular component before fixation of the anterior pelvic disruption, which can be easily performed during the same surgical procedure, allowed for easier restoration of the joint space and prevented distraction of acetabular fragments. Likewise, fixation of the posterior acetabular component before fixation of the posterior pelvic disruption prevented a similar distractive force. Also, posterior stabilizing structures are stronger and can better withstand the forces generated during anterior reduction and fixation. For this reason, posterior components were reduced and fixed only after anterior structures were stabilized.