title: Radial head replacement with a bipolar system: a minimum 2-year follow-up.
abstract: BACKGROUND
  We report the short-term results of a cohort of patients undergoing radial head replacement using a novel radial head prosthesis with a smooth, unfixed, telescoping stem and a bipolar design after a mean follow-up of 34 months (range, 24-48 months).
  
  
  METHODS
  Patients were assessed using clinical and radiographic examination as well as with standardized outcome measures. Thirty implants (29 patients) were available for review.
  
  
  RESULTS
  At final follow-up, the average Mayo Elbow Performance Index Score was 92.1 and the Disabilities of the Arm, Shoulder, and Hand Score was 13.8. Clinical examination revealed significant differences between operative and nonoperative sides for flexion/extension and pronation/supination. Radiographic measurement of medial and lateral ulnohumeral spaces revealed re-establishment of a congruent elbow joint. No significant arthritic changes were identified at the radiocapitellar joint. Minimal angular migration of the implant in the proximal radial shaft was observed over time. Complications included 1 patient requiring temporary placement of a hinged external fixator for instability and 1 patient requiring revision surgery at 4 weeks.
  
  
  CONCLUSIONS
  This review demonstrates that a bipolar radial head prosthesis with a smooth stem and telescoping neck effectively restores stability to elbows with a comminuted radial head fracture and valgus instability. To date, this is the largest reported outcome analysis of bipolar radial head replacement in the literature.
authors.affiliation: Department of Orthopaedic Surgery, Allegheny General Hospital, Pittsburgh, PA, USA. drzunk@hotmail.com
authors.forename: Mark R
authors.initials: MR
authors.lastname: Zunkiewicz
authors.forename: Jill S
authors.initials: JS
authors.lastname: Clemente
authors.forename: Mark C
authors.initials: MC
authors.lastname: Miller
authors.forename: Mark E
authors.initials: ME
authors.lastname: Baratz
authors.forename: Robert W
authors.initials: RW
authors.lastname: Wysocki
authors.forename: Mark S
authors.initials: MS
authors.lastname: Cohen
mesh_terms: D004551:Elbow Joint / Q000601:surgery*; D016267:External Fixators; D005260:Female; D005500:Follow-Up Studies; D018460:Fractures, Comminuted / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D007595:Joint Prosthesis; D008297:Male; D011474:Prosthesis Design; D011859:Radiography; D011884:Radius / Q000601:surgery; D011885:Radius Fractures / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome