title: Troublesome heterotopic ossification after central nervous system damage: a survey of 570 surgeries.
abstract: BACKGROUND
  Heterotopic ossification (HO) is a frequent complication after central nervous system (CNS) damage but has seldom been studied. We aimed to investigate features of HO for the first time in a large sample and the rate of early recurrence of HO in terms of the time of surgery.
  
  
  RESULTS
  We retrospectively analyzed data from an anonymous prospective survey of patients undergoing surgery between May 1993 and November 2009 in our institution for troublesome HO related to acquired neurological disease. Demographic and HO characteristics and neurological etiologies were recorded. For 357 consecutive patients, we collected data on 539 first surgeries for HO (129 surgeries for multiple sites). During the follow-up, recurrences requiring another surgery appeared in 31 cases (5.8% [31/539]; 95% confidence interval [CI]: 3.8%-7.8%; 27 patients). Most HO requiring surgery occurred after traumatic brain injury (199 patients [55.7%]), then spinal cord injury (86 [24.0%]), stroke (42 [11.8%]) and cerebral anoxia (30 [8.6%]). The hip was the primary site of HO (328 [60.9%]), then the elbow (115 [21.3%]), knee (77 [14.3%]) and shoulder (19 [3.5%]). For all patients, 181 of the surgeries were performed within the first year after the CNS damage, without recurrence of HO. Recurrence was not associated with etiology (p = 0.46), sex (p = 1.00), age at CNS damage (p = 0.2), multisite localization (p = 0.34), or delay to surgery (p = 0.7).
  
  
  CONCLUSIONS
  In patients with CNS damage, troublesome HO and recurrence occurs most frequently after traumatic brain injury and appears frequently in the hip and elbow. Early surgery for HO is not a factor of recurrence.
authors.affiliation: Service de Médecine Physique et de Réadaptation, Hôpital Raymond Poincaré, Garches, France. francois.genet@rpc.aphp.fr
authors.forename: François
authors.initials: F
authors.lastname: Genêt
authors.forename: Claire
authors.initials: C
authors.lastname: Jourdan
authors.forename: Alexis
authors.initials: A
authors.lastname: Schnitzler
authors.forename: Christine
authors.initials: C
authors.lastname: Lautridou
authors.forename: Didier
authors.initials: D
authors.lastname: Guillemot
authors.forename: Thierry
authors.initials: T
authors.lastname: Judet
authors.forename: Serge
authors.initials: S
authors.lastname: Poiraudeau
authors.forename: Philippe
authors.initials: P
authors.lastname: Denormandie
mesh_terms: D001134:Arm Injuries / Q000150:complications; D001930:Brain Injuries / Q000150:complications; D002490:Central Nervous System / Q000293:injuries* / Q000473:pathology* / Q000601:surgery; D003625:Data Collection; D004551:Elbow Joint / Q000473:pathology; D025981:Hip Injuries / Q000150:complications; D006801:Humans; D009999:Ossification, Heterotopic / Q000209:etiology* / Q000601:surgery; D011183:Postoperative Complications / Q000473:pathology*; D012008:Recurrence; D012189:Retrospective Studies; D000092464:Elbow Injuries