Radial head replacement for acute complex fractures: what are the rate and risks factors for revision or removal?

BACKGROUND: When treating complex radial head fractures, important goals include prevention of elbow or forearm instability, with restoration of radiocapitellar contact essential. When open reduction and internal fixation cannot achieve this, radial head replacement is routinely employed, but the frequency of and risk factors for prosthesis revision or removal are not well defined. QUESTIONS/PURPOSES: We determined (1) the frequency of prosthesis revision or removal after radial head replacement for acute complex unstable radial head fractures, (2) risk factors for revision or removal, and (3) functional outcomes after radial head replacement.
METHODS: We identified from our prospective trauma database all patients over a 16-year period managed acutely for unstable complex radial head fractures with primary radial head replacement. Of the 119 patients identified, 105 (88%) met our inclusion criteria; mean age was 50 years (range, 16-93 years) and 57 (54%) were female. All implants were uncemented monopolar prostheses, of which 86% were metallic and 14% silastic. We recorded further procedures for prosthesis revision or removal for any cause, with a minimum followup of 1 year (n = 105). Cox regression analysis was used to determine independent factors associated with revision or removal when controlling for baseline patient (age, sex, comorbidities) and fracture (location, classification, associated injury) characteristics. Short-term functional outcomes (Broberg and Morrey score, ROM) were determined from retrospective review of clinic followup (n = 74), with a minimum followup of 3 months.
RESULTS: Twenty-nine patients (28%) underwent prosthesis revision (n = 3) or removal (n = 26) at a mean of 6.7 years (range, 1.8-18 years) after injury. Independent risk factors for removal or revision were silastic implant type and lower age. At a mean of 1.1 years (range, 0.3-5.5 years) after surgery, mean Broberg and Morrey score was 80 out of 100 (range, 40-99). Mean elbow flexion was 133° (range, 90°-159°; SD, 13°), extension 21° (range, 0°-80°; SD, 17°), flexion arc 112° (range, 10°-140°; SD, 25°), pronation 84° (range, 0°-90°; SD, 18°), supination 73° (range, 0°-90°; SD, 28°), and forearm rotation arc 156° (range, 0°-180°; SD, 38°).
CONCLUSIONS: We demonstrated a high removal or revision rate after radial head replacement for acute unstable complex fractures, with lower age and silastic implants independent risk factors. Younger patients should be counseled regarding the increased risk of requiring further surgery after radial head replacement. Future work should focus on long-term patient-reported outcomes after these injuries. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.