Risk of radial head arthroplasty revision is correlated with radial head diameter: a multicenter analysis of 405 cases.

BACKGROUND: Radial head arthroplasty (RHA) is commonly used for the treatment of comminuted radial head fractures. Indications as well as implant types continue to evolve. RHA has had good outcomes with midterm longevity. The literature is limited to small case series with varying implant types, and larger studies are needed to determine the optimal implant type and radial head diameter. METHODS: A retrospective analysis of RHA cases performed by 75 surgeons at 14 medical centers in an integrated health care system between 2006 and 2017 was completed. Patient demographics, comorbidities, implant type and head diameter, and indications for revision were recorded. Patients' in-person clinical visit data were recorded. Patients were also contacted via telephone at a minimum of 2 years to obtain abbreviated Disabilities of the Arm, Shoulder, and Hand questionnaire and Oxford scores. Implant survivorship was also captured within our integrated system. RESULTS: 405 cases met our inclusion criteria. Mean age was 51.5 ± 15.5 years (range 16-88 years) and more common in females (62%). Chart review and telephone follow-up was performed at a mean of 68.9 ± 31.5 months (range 24-146 months). Our study found that revision rate was positively correlated with increasing radial head diameter. A 26-mm head had 7.7 odds of revision compared to a size 18-mm head (95% confidence interval 1.2-150.1). More than 95% of revision cases were performed within the first 36 months of the index procedure. Obese patients had a significantly lower mean postoperative Oxford score (35.5) compared to controls (38.3) (P = .02). There was a significantly higher overall reoperation rate for terrible triad (18.4%) vs. isolated injuries (10.4%) (P = .04). There was no difference between Acumed Anatomic and Evolve radial head implants in overall reoperation, implant revision, postoperative range of motion, or patient-reported outcomes. CONCLUSIONS: Risk of revision is directly correlated with implanted radial head diameter. There were no differences in outcomes and complications between the 2 main implants used. Individuals who did not undergo a revision by 3 years' time tend to retain the implant. Terrible triad injuries had a higher all-cause reoperation rate than isolated radial head fractures, but no difference in the rate of RHA revision. These data reinforce the practice of downsizing radial head implant diameter.