ABSTRACT
BACKGROUND: Radial head arthroplasty is recognized as the gold standard in the treatment of patients with unreconstructable radial head fractures. OBJECTIVE: The aim of this retrospective study was to investigate the long-term results after prosthetic replacement of the radial head and in a subgroup analysis to identify factors which influence the outcome. MATERIAL AND METHODS: A total of 48 patients with unreconstructable fractures of the radial head and neck were treated by cementless radial head arthroplasty between 05/2008 and 10/2018 (30 bipolar prosthesis type rHead Recon, 18 monopolar prosthesis type MoPyc). After a mean follow-up of 4.6 years 39 patients were assessed clinically and radiologically. RESULTS: The median MEP score was 95 points. Compared to the uninjured side the median range of motion was reduced by 10° for extension/flexion as well as for pronation/supination. In 36 of 39 cases an osseous integration of the prosthesis could be documented. One prosthesis had to be removed after 23 months because of painful loosening. Overlengthening was present in 11 cases (28%), 25 patients (64%) had subcollar bone resorption with a stable osteointegrated stem. Nonbridging heterotopic ossification was observed in 15 patients (38%), 16 patients (41%) showed posttraumatic arthrosis. Patients with sustained elbow dislocation had a significantly worse function in the MEP score and tended to develop an arthrosis more frequently. Ulnohumeral joint degeneration was significantly increased when overlengthening was present. CONCLUSION: Radial head arthroplasty is an effective treatment option for unreconstructable fractures of the radial head and can provide good to excellent mid-term to long-term results. Sustained elbow dislocation as well as overlengthening of the prosthesis had a negative impact on the clinical outcome.