Background: Comminuted fractures of the radial head are challenging to treat with open reduction and internal fixation. Radial head arthroplasty is an alternative treatment with results that compare favorably with those reported after open reduction and internal fixation of similar fractures. The purpose of this study was to evaluate the two-year outcomes and the rate of recovery of a closely followed cohort of patients in whom an unreconstructible radial head fracture had been treated with a modular metallic prosthesis.

Methods: Twenty-six patients (seventeen female and nine male; mean age, fifty-four years) with an unreconstructible comminuted radial head fracture and associated elbow injuries were treated with a modular metallic radial head arthroplasty. Patients who had presented more than four weeks following the injury or had had the radial head arthroplasty as a second-stage or salvage procedure were excluded. Of the twenty-six patients, twenty-two had an associated elbow dislocation, and thirteen of them also had an associated fracture of the coronoid process. Patients were prospectively followed at three, six, twelve, and twenty-four months. Self-reported limb function, general health, range of motion, and isometric strength were assessed by an independent observer.

Results: Following treatment of the injury, significant decreases in self-reported and measured impairments were noted over time, with the majority of the recovery occurring by six months and little further recovery noted between six and twenty-four months. There were slight-to-moderate deficits in the range of motion and strength compared with the values on the contralateral, unaffected side. Patient satisfaction was high at three months and remained high at two years. All elbow joints remained stable, no implant required revision, and there was no evidence of overstuffing of the joint. Mild osteoarthritis was seen in five (19%) of the twenty-six patients.

Conclusions: An arthroplasty with a modular metallic radial head is a safe and effective option for the treatment of unreconstructible radial head fractures associated with other elbow injuries. Recovery primarily occurs by six months, with minimal additional improvements over the next eighteen months.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.