Comparative study of total shoulder arthroplasty versus total shoulder surface replacement for glenohumeral osteoarthritis with minimum 2-year follow-up.

BACKGROUND: Compared with total shoulder arthroplasty (TSA), total shoulder surface replacement (TSSR) may offer the advantage of preservation of bone stock and shorter surgical time, possibly at the expense of glenoid component positioning and increasing lateral glenohumeral offset. We hypothesized that in patients treated for osteoarthritis with a sufficient rotator cuff, TSA and TSSR patients have comparable functional outcome, glenoid component version, and lateral glenohumeral offset.

METHODS: We conducted a retrospective cohort study with a minimum of 2 years of follow-up. Patients in the TSA and TSSR groups received a cemented, curved, keeled, all-poly glenoid component. A cemented anatomical humeral stem was used in TSA. TSSR involved a humeral surface replacement (all components from Tornier Inc., St Ismier, France). Patients were assessed for functional outcome. Radiographs were assessed for radiolucent lines. Glenoid component position and lateral glenohumeral offset were assessed using computed tomography images.

RESULTS: After 29 and 34 months of mean follow-up, respectively, TSA (n = 29) and TSSR (n = 20) groups showed similar median adjusted Constant Scores (84% vs. 88%), Oxford Shoulder Scores (44 vs. 44), Disabilities of the Arm, Shoulder and Hand scores (22 vs. 15), and Dutch Simple Shoulder Test scores (10 vs. 11). Glenoid components showed similar radiolucent line counts (median, 0 vs. 0), similar anteversion angles (mean, 0° vs. 2°), and similar preoperative to postoperative increases in lateral glenohumeral offset (mean, 4 vs. 5 mm). One intraoperative glenoid fracture occurred in the TSSR group.

CONCLUSION: Short-term functional and radiographic outcomes were comparable for TSA and TSSR.