title: Heterotopic ossification rates after acetabular fracture surgery are unchanged without indomethacin prophylaxis.
abstract: BACKGROUND
  We previously found no reduction in heterotopic ossification (HO) rates after acetabular surgery with indomethacin compared with a placebo. We subsequently abandoned routine indomethacin therapy after acetabular surgery but questioned whether the incidence had changed using a posterior approach.
  
  
  OBJECTIVE
  We therefore determined (1) the incidence of HO after acetabular fracture surgery through a posterior approach; (2) the incidence of symptoms attributable to HO; and (3) the rate of reoperation for HO.
  
  
  METHODS
  We retrospectively reviewed the records of all 423 patients with acetabular fractures following our clinical protocol change; of these, 120 were treated with a Kocher-Langenbeck approach and included. The presence of radiographic HO was documented a minimum of 10 weeks postoperatively using the classification of Brooker et al. Symptoms and reoperations were recorded.
  
  
  RESULTS
  The overall incidence of radiographic HO was 47% (56 of 120 patients): 26% Class I-II 13% Class III, and 8% Class IV. Overall, 15% of patients developed symptoms; 3.3% underwent reoperations for excision of HO. There were no major differences between the incidence of moderate and severe HO in this study when compared with the indomethacin and placebo groups from the prior study.
  
  
  CONCLUSIONS
  Our incidence of moderate and severe HO has not changed since discontinuing indomethacin. These findings support our institutional decision to abandon routine indomethacin prophylaxis after acetabular surgery. We recommend improved surgical techniques to limit damage to the abductors and improved risk stratification of patients when considering treatment options for HO prophylaxis.
authors: Department of Orthopaedic Surgery, Division of Orthopaedic Trauma, Carolinas Medical Center, 1320 Scott Avenue, Charlotte, NC 28232, USA. smgrif0@gmail.com
authors: Sean M
authors: SM
authors: Griffin
authors: Stephen H
authors: SH
authors: Sims
authors: Madhav A
authors: MA
authors: Karunakar
authors: Rachel
authors: R
authors: Seymour
authors: Nikkole
authors: N
authors: Haines
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000009:adverse effects*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D015994:Incidence; D007213:Indomethacin / Q000627:therapeutic use*; D015601:Injury Severity Score; D008297:Male; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D015995:Prevalence; D011859:Radiography; D012042:Registries; D012086:Reoperation; D012189:Retrospective Studies; D012737:Sex Factors
chemical_list: D007213:Indomethacin