title: Heterotopic ossification following traumatic and combat-related amputations. Prevalence, risk factors, and preliminary results of excision.
abstract: BACKGROUND
  Although infrequently reported in amputees previously, heterotopic ossification has proven to be a common and problematic clinical entity in our recent experience in the treatment of traumatic and combat-related amputations related to Operation Enduring Freedom and Operation Iraqi Freedom. The purpose of the present study was to report the prevalence of and risk factors for heterotopic ossification following trauma-related amputation as well as the preliminary results of operative excision.
  
  
  METHODS
  We identified 330 patients with a total of 373 traumatic and combat-related amputations who had been managed at our centers between September 11, 2001 and November 30, 2005. We reviewed the medical records and radiographs of 187 patients with 213 amputations who had adequate radiographic follow-up. Additional analysis was performed for twenty-four patients with twenty-five limbs that required excision of symptomatic lesions. The mechanism and zone of injury, amputation level, timing of excision, use of prophylaxis against recurrence, and other confounding variables were examined. Outcomes were assessed by determining clinical and radiographic recurrence rates, perioperative complications, preoperative and follow-up pain medication requirements, and the ability to be fit with a functional prosthesis.
  
  
  RESULTS
  Heterotopic ossification was present in 134 (63%) of 213 residual limbs, with twenty-five lesions requiring excision. A final amputation level within the zone of injury was a risk factor for both the development and the grade of heterotopic ossification (p < 0.05). A blast mechanism was predictive of occurrence (p < 0.05) but did not correlate with grade. All patients who had been managed with excision were tolerating the prosthetic limb at an average of twelve months of follow-up. Twenty-three limbs demonstrated no evidence of recurrence, and two limbs had development of clinically asymptomatic, radiographically minimal recurrences. Six patients experienced wound-related complications that required reoperation, and two patients required subsequent minor revision surgery. There was a significant decrease in the use of pain medication following surgery (p < 0.05).
  
  
  CONCLUSIONS
  Heterotopic ossification following trauma-related amputation is more common than the literature would suggest, particularly following amputations that are performed within the initial zone of injury and those that are due to blast injuries. Many patients are asymptomatic or can be successfully managed with modification of the prosthesis. For patients with refractory symptoms, surgical excision is associated with low recurrence rates and decreased medication requirements, with acceptable complication rates.
authors.affiliation: Orthopaedic Surgery, Department of Orthopaedics and Rehabilitation, Walter Reed Army Medical Center, 6900 Georgia Avenue N.W., Building 2, Clinic 5A, Washington, DC 20307, USA. Benjamin.Potter@na.amedd.army.mil
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Potter
authors.forename: Travis C
authors.initials: TC
authors.lastname: Burns
authors.forename: Anton P
authors.initials: AP
authors.lastname: Lacap
authors.forename: Robert R
authors.initials: RR
authors.lastname: Granville
authors.forename: Donald A
authors.initials: DA
authors.lastname: Gajewski
mesh_terms: D000328:Adult; D000671:Amputation, Surgical / Q000009:adverse effects*; D000672:Amputation Stumps / Q000000981:diagnostic imaging / Q000473:pathology*; D000673:Amputation, Traumatic / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008889:Military Personnel; D009999:Ossification, Heterotopic / Q000453:epidemiology / Q000209:etiology*; D011183:Postoperative Complications; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D013529:Surgical Wound Dehiscence / Q000601:surgery; D014481:United States