Risk Factors for the Development of Heterotopic Ossification After Acetabular Fracture Fixation

Abstract

Background Heterotopic ossification (HO) is a common complication of the operative treatment of acetabular fractures. Although the surgical approach has been shown to correlate with the development of ectopic bone, specific risk factors have not been elucidated. Questions/purposes The purposes of this study were to determine specific risk factors associated with the development of severe HO and the frequency with which patients develop severe HO after acetabular fracture fixation through an isolated Kocher-Langenbeck approach. Methods Using an institutional orthopaedic trauma database at a regional Level I trauma center, patients undergoing open treatment of acetabular fractures during the study period (January 2000 to January 2010) were identified. A review of medical records and imaging studies was performed on 508 patients who were treated by the senior author (MR) through an isolated Kocher-Langenbeck approach. During the study period, the senior author used indomethacin for HO prophylaxis in patients who had ipsilateral femur fracture treated with antegrade reamed medullary nailing or severe local soft tissue injury; 49 (10%) of the patients he treated with the Kocher-Langenbeck approach received prophylaxis, and they were excluded from this study, leaving a total of 459 patients who met inclusion criteria. Of those, 147 (29%) were lost to followup or did not have radiographs both before and at a minimum of 6 weeks (median, 1 week; range, 0-3 weeks), leaving 312 (61% of the patients treated with the Kocher-Langenbeck approach during this time) available for this analysis. Demographic data as well as information related to cause of injury, associated periacetabular findings, other system injuries, and treatment were gathered. Final followup radiographs were assessed for the presence of ectopic bone by two of the authors (TJO, AS) using the modified Brooker classification. Logistic regression was performed to identify possible predictors of development of severe ectopic bone. Results The only predictor we identified for the development of severe HO was the need for prolonged mechanical ventilation (odds ratio, 7

Does Postoperative Radiation Decrease Heterotopic Ossification After the Kocher-Langenbeck Approach for Acetabular Fracture?

“…Although some studies support prophylaxis in high-risk patients [4,6,10,21], there is currently no consensus as to which prophylactic measure is the most efficacious. Previous studies have demonstrated the value of gluteus minimus débridement in reducing the risk of HO and compared its effectiveness with that of indomethacin [10,20,22]. To our knowledge, this is the first study comparing the effectiveness of gluteus minimus débridement with and without radiotherapy.…”

“…Patients with fewer than 10 weeks followup (n = 12) were excluded, because several studies [10,19,20] suggest that most HO that develops is visible by that point in time. Three of 27 patients in the radiotherapy and débridement group were excluded for insufficient followup and nine of 31 patients in the débridement-only group were excluded.…”

“…Débridement of gluteus minimus muscle caudal to the superior gluteal bundle was standard in all patients. The muscle bellies of the superior and inferior gemelli muscles are also débrided from the obturator internus tendon to the level of the lesser sciatic notch [10,20]. Open reduction and internal fixation then proceeded in a standard fashion as indicated per fracture type.…”

“…Heterotopic bone formation is most commonly seen after extended iliofemoral or Kocher-Langenbeck approaches for acetabular reduction and fixation [1,4,11,21]. Other reported risk factors for HO include craniocerebral trauma, fractures associated with posterior hip dislocation, operative delay, ventilation requirement[72 hours, and race [1,4,10,20,24,26]. The most commonly used prophylactic modalities are indomethacin, single-dose radiotherapy, and gluteus minimus débridement.…”

Treatments and Preventative Measures for Trauma‐Induced Heterotopic Ossification: A Review

“…Posterior approaches for acetabular surgery, such as the Kocher‐Langenbeck approach, increase the risk of HO formation in the gluteus minimus muscle. This has been demonstrated by a decreased incidence of HO when necrotic gluteus minimus tissue is debrided after acetabular fracture fixation 4, 5. The upper extremity is also affected, especially following surgical approaches about the elbow.…”