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.