Radial Head Fractures Treated with Modular Metallic Radial Head Replacement: Outcomes at a Mean Follow-up of Eight Years.

BACKGROUND Radial head arthroplasty is commonly used to treat acute unreconstructible radial head fractures. The purpose of this study was to report on the clinical and radiographic outcomes at a minimum follow-up of five years after radial head arthroplasty with a modular metallic implant for the treatment of acute radial head fractures. METHODS The cases of fifty-five patients with unreconstructible radial head fractures treated acutely with a smooth-stemmed modular metallic radial head implant were retrospectively reviewed. A wide variety of injuries, which ranged from isolated radial head fractures to so-called terrible triad injuries, were included. All patients returned for an interview, physical examination, and radiographic evaluation at a mean of eight years (range, five to fourteen years) postoperatively. Elbow and forearm motion, elbow strength, and grip strength were measured. Radiographs were evaluated, and validated patient-rated outcome questionnaires were completed. A longitudinal subgroup analysis was performed for thirty-three patients who were previously evaluated at two years postoperatively. RESULTS At a mean of 8.2 ± 2.9 years, the mean arc of flexion (and standard deviation) of the affected elbow was 11° ± 14° to 137° ± 15°. Elbow strength and motion were significantly diminished compared with the unaffected elbow (p < 0.05). The mean Mayo Elbow Performance Index (MEPI) was 91 ± 13 points. Twenty-five patients (45%) had stem lucencies; twenty-one (38%), ulnohumeral arthritis; and twenty (36%), heterotopic ossification, including one with radioulnar synostosis. Two patients underwent secondary elbow surgery, but no patient required implant removal or revision. In the subgroup evaluated longitudinally, there was a significant improvement in MEPI scores from the two-year to the eight-year follow-up (p = 0.012), with no loss of motion or strength (p > 0.05). CONCLUSIONS The mid-term outcomes of radial head arthroplasty with a smooth-stemmed modular metallic prosthesis are comparable with previously reported short-term outcomes, with no evidence of functional deterioration. Radial head arthroplasty with a smooth-stemmed metallic modular implant is a good treatment option for patients with acute unreconstructible radial head fractures, and sustained clinical outcomes may be expected beyond five years of follow-up. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.