A multicenter, prospective 2-year analysis of the Sidus stem-free shoulder arthroplasty system

BACKGROUND: The purpose of this multicenter, prospective study was to evaluate the efficacy and safety of a stemless total shoulder arthroplasty compared with a traditional stemmed control. METHODS: Ninety-five shoulders were selected for participation in this Food and Drug Administration investigational device exemption clinical trial and underwent stemless total shoulder arthroplasty. Subjects returned for follow-up at 6 weeks, 6 months, 12 months, and 2 years postoperatively. Outcome measures included pain; range of motion; American Shoulder and Elbow Surgeons, Western Ontario Osteoarthritis of the Shoulder, and Short Form 12 scores; and radiographic review. Baseline data were compared with 2-year follow-up data to determine the rate of composite clinical success compared with the stemmed control. RESULTS: All outcome assessments demonstrated significant improvements (P ≤ .007). The mean American Shoulder and Elbow Surgeons score improved from 20 to 89 (P < .0001), and the mean shoulder pain score decreased from 8.3 ± 1.6 to 0.7 ± 1.5 (P < .0001). The mean Western Ontario Osteoarthritis of the Shoulder score decreased from 1443 ± 256 to 203 ± 267 (P < .0001). On the Short Form 12, the mean physical health score increased from 33 ± 7 to 48 ± 9 (P < .0001) and the mean mental health score increased from 50 ± 13 to 54 ± 8 (P = .007). Mean active forward elevation increased from 97° ± 27° to 143° ± 25° (P < .0001), and mean active external rotation increased from 21° ± 16° to 53° ± 18° (P < .0001). Kaplan-Meier analysis showed an implant survivorship rate of 98% at 2 years. The composite clinical success rate was 87% compared with 85% for the stemmed control. CONCLUSIONS: This study showed that a stemless rough-blasted humeral implant with metaphyseal bone fixation provides good clinical and radiographic outcomes and survivorship at 2 years, with outcomes comparable to a traditional stemmed implant.