LAUSR

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.