10/5/12 Pelvis & Acetabulum, PAPER #65, 4:08 pm OTA-2012
•Incidence of Posterior Wall Nonunion and Efficacy of Indomethacin Prophylaxis for Heterotopic Ossification After Operative Fixation of Acetabular Fractures: A Randomized Controlled Trial
Charles J. Jordan, MD; Rafael Serrano-Riera, MD; H. Claude Sagi, MD;
Orthopaedic Trauma Service, Florida Orthopaedic Institute, Tampa, Florida, USA
Background/Purpose: Clinically significant heterotopic ossification (HO) about the hip joint (Brooker 3 or 4) after operative fixation of an acetabular fracture is a rare, but potentially devastating, complication. Postoperative indomethacin for variable time periods has been recommended as prophylaxis, but controversy exists within the current literature as to its efficacy and safety. Additionally, the use of indomethacin prophylaxis has been reported to increase the incidence of long bone nonunion. Currently no study exists to document the effects of variable durations of indomethacin prophylaxis and its relationship to both HO and union of the posterior wall (PW). The purpose of this study is to document the efficacy of variable treatment durations with indomethacin prophylaxis for HO and its effect on union of the PW in operatively treated acetabular fractures.
Methods: From 2004 to 2011, 98 skeletally mature patients with an acetabular fracture requiring a posterior surgical approach for fixation were enrolled in a prospective randomized study at a single institution. ll patients underwent open reduction and internal fixation through a Kocher-Langenbeck approach. Patients were randomly assigned to one of four treatment groups: (1) placebo for 6 weeks, (2) 3 days of indomethacin followed by placebo for a total of 6 weeks, (3) 1 week of indomethacin followed by 5 weeks of placebo, and (4) 6 weeks of indomethacin. Patients were followed clinically and radiographically at 1 month, 3 months, 6 months, and 1 year. At each postoperative visit, data were collected on range of motion, pain (visual analog scale [VAS] score), and radiographic presence of HO (Brooker classification). Patients underwent pelvic CT at 6 months to assess healing and for volumetric quantification of HO. All prospective data were analyzed using standard statistical methods, in order to detect differences in the abundance of HO and nonunion with varying durations of treatment, as well as differences in function and pain between groups.
Results: Mean age and gender distribution did not differ significantly between groups. While the overall incidence of any HO on radiographs at 1 year was greater with placebo (group 1) when compared to groups 2 and 3 (P = 0.046 and P = 0.019, respectively), the amount of HO based on CT volumetric analysis and the incidence of clinically significant HO (decreased range of motion and increased VAS pain) was no different between any group at 6 months or 1 year. The overall incidence of PW nonunion was 20% for group 1 (placebo), 35% for group 2, 24% for group 3, and 50% for group 4 (P <0.05). While range-of-motion scores did not differ between those with and without PW nonunion, the pain VAS for those with CT-detected PW nonunion was significantly higher (3 vs 1.5, P = 0.044).
Conclusion: The use of prophylactic postoperative indomethacin does not have a demonstrable effect on the volume or incidence of clinically significant HO after operatively treated acetabular fractures. Additionally, the data from this analysis suggest that the use of prophylactic postoperative indomethacin increases the incidence of symptomatic nonunion of the PW as assessed by CT scan and pain VAS. Based on the results of this randomized trial, we do not recommend the use of indomethacin as prophylaxis against HO after operative treatment of acetabular fractures.
Funding: Aided by a grant from the Orthopaedic Research and Education Foundation (OREF).
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• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.