title: Factors associated with removal of a radial head prosthesis placed for acute trauma.
abstract: OBJECTIVE
  This study tests the hypothesis that there are no factors associated with removal or revision of a radial head prosthesis. A secondary analysis addressed the time to removal or revision.
  
  
  METHODS
  We reviewed the database of two large hospitals from 2000 to 2014 and identified 278 patients that had radial head replacement after an acute fracture or fracture dislocation of the elbow: 19 had removal and 3 had revision of the radial head implant within the study period. Explanatory variables including demographics, the type of injury, prosthesis type, surgeon, medical centre, and associated injuries were evaluated. Survival analysis using Kaplan-Meier curves evaluated time to removal/revision.
  
  
  RESULTS
  After adjustment for potential confounders using Cox regression multivariable analysis, hospital was the only factor independently associated with removal or revision (Hazard ratio=2.4, Confidence interval: 1.03-5.8, P value=0.043). The highest proportion of removal/revision was during the first year after implantation and decreased by half each year over the second to fourth years. The most common reason for removal of the prosthesis was to facilitate removal of heterotopic ossification (the majority with proximal radioulnar synostosis) rather than technical error or problems with the prostheses.
  
  
  CONCLUSIONS
  These findings suggest that the decision to remove a radial head prosthesis may depend more on surgeon or hospital preferences than on objective problems with the prosthesis. Until clarified by additional study, removal of a prosthesis should not be considered an objective outcome in research. In addition, patients offered removal of a radial head prosthesis, might get the opinion of more than one surgeon at more than one hospital before deciding whether or not to proceed.
  
  
  METHODS
  Level III Prognostic.
authors.affiliation: Orthopedic Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: akachooei@mgh.harvard.edu.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Kachooei
authors.affiliation: Hand and Upper Extremity Service, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: fclaessen@mgh.harvard.edu.
authors.forename: Femke M A P
authors.initials: FM
authors.lastname: Claessen
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: smchase@partners.org.
authors.forename: Samantha M
authors.initials: SM
authors.lastname: Chase
authors.affiliation: Hand and Upper Extremity Service, Massachusetts General Hospital, Boston, Massachusetts, USA. Electronic address: kverheij@mgh.harvard.edu.
authors.forename: Kirsten K J
authors.initials: KK
authors.lastname: Verheij
authors.affiliation: Department of Orthopaedic Surgery, Academic Medical Center Amsterdam, Amsterdam, The Netherlands. Electronic address: c.n.vandijk@amc.uva.nl.
authors.forename: C Niek
authors.initials: CN
authors.lastname: van Dijk
authors.affiliation: Dell Medical School - The University of Texas at Austin, 1400 Barbara Jordan Blvd. Suite 1.114AC. MC: R1800, Austin, TX 78723, USA. Electronic address: david.ring@austin.utexas.edu.
authors.forename: David
authors.initials: D
authors.lastname: Ring
mesh_terms: D000328:Adult; D057929:Arthroplasty, Replacement, Elbow / Q000295:instrumentation; D020878:Device Removal / Q000706:statistics & numerical data*; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D058569:Elbow Prosthesis; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000503:physiopathology / Q000601:surgery; D007593:Joint Instability / Q000503:physiopathology / Q000601:surgery; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D011859:Radiography; D011885:Radius Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016059:Range of Motion, Articular; D012086:Reoperation / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult; D000092464:Elbow Injuries
keywords: Elbow fracture dislocation; Prosthesis; Radial head; Removal; Revision; Survival