Clinical and radiological results of a cementless short stem shoulder prosthesis at minimum follow-up of two years.

Purpose: Uncemented short stem shoulder arthroplasty combines the advantages of a bone-saving implantation with a straightforward revision option. Uncemented humeral long stems can be associated with stress shielding and loosening. Therefore, we analysed the clinical and radiological outcome of a short stem shoulder prosthesis with metaphyseal fixation.

Methods: This two-centre study included 82 total shoulder arthroplasties in 80 patients with short stem shoulder prosthesis and a cemented polyethylene glenoid performed between 2010 and 2012. Sixty-eight shoulders had primary osteoarthritis, eight shoulders had post traumatic sequelae and six had other diagnoses. Minimum follow-up was two years. Outcome data included the Constant Score (CS), Subjective Shoulder Value (SSV), Pain Scale (0-15) and range of motion. Radiographic evaluation was done in shoulders with primary osteoarthritis in a standard view.

Results: The mean clinical and radiological follow-up was 31.2 ± 7.2 months (20-52). CS improved from 36.7 ± 15.2 % to 90.4 ± 16.4% and SSV improved from 39.4 ± 15.5 points to 85.5 ± 13.2 points (p < 0.0001). Pain was rated as mild or none in 76 shoulders (92.7%) with a mean value of 13.2 ± 2.6. The mean active flexion was 157.0 ± 24.7°, abduction was 152.6 ± 29.1° and the active external rotation was 38.2 ± 14.8° at recent follow-up. Radiographic assessment was done in 44 shoulders. Six shoulders (13.6%) showed features of slight stress shielding at the medial cortex and no stem with subsidence was found. Three glenoids (6.8%) had minor radiolucent lines.

Conclusions: Uncemented short stem shoulder arthroplasty with a cemented polyethylene glenoid can yield a stable fixation with a good clinical outcome at minimum follow-up of two years.