gms | German Medical Science

Objectives: The purpose of this large scale database analysis is to quantify the clinical outcomes with a minimum follow-up of 2 years using 5 different metrics and compare results achieved for each indication using one platform TSA system which utilizes the same humeral component and instrumentation to perform both aTSA or rTSA.

Methods: An international multicenter data registry was utilized. 863 patients with a mean age of 69 years (range 31-93 yrs) were treated by 12 orthopaedic surgeons using either aTSA or rTSA. 385 patients received aTSA (mean age 67 yrs) for OA and 478 patients received rTSA (mean age 71 yrs) for treatment of CTA and OA. These patients were scored pre-operatively and at latest follow-up using the SST, UCLA, ASES, Constant, and SPADI metrics; active abduction, forward flexion, and active and passive external rotation were also measured. The average follow-up for all patients was 36 months (aTSA 38 months; rTSA 34 months). A Student's two-tailed, unpaired t-test was used to identify differences in pre-op, post-op, and improvements.

Results and Conclusion: All patients demonstrated significant improvements in pain and function following aTSA and rTSA. For aTSA, ASES scores improved from 36 to 87, Constant scores from 37 to 73 (p <0.0001). Significant improvements were also seen in the SST, UCLA and SPADI scores (p < 0.0001). For rTSA, ASES scores improved from 33 to 85, Constant scores from 30 to 72 (p <0.0001), and significant improvements were also seen in the SST, UCLA and SPADI scores (p < 0.0001). Active forward flexion for aTSA improved from 98° to 147° and active external rotation from 12° to 45°. Active forward flexion for rTSA improved from 81° to 140° and active external rotation from 12° to 33° (all p < 0.0001). rTSA had significantly lower pre-operative scores as measured by 4 of the 5 metrics and significantly less motion as measured by 3 of the 4 measurements relative to aTSA (p <0.0001). Both aTSA and rTSA provided significant improvements in all 5 outcome scores and all 4 motion measurements at follow-up. Several comparative differences were observed. aTSA was associated with significantly higher post-operative scores for 2 of the 5 metrics, significantly greater range of motion for all 4 motion measurements, and significantly greater improvements in the SPADI metric and both active and passive external rotation. rTSA was associated with significantly greater improvements in outcome scores according to 2 of the 5 metrics and was significantly more effective at improving active forward flexion. The complication rate was 2.1% for aTSA compared with 6.9% for rTSA. Patients undergoing rTSA are generally worse off preoperatively than those undergoing aTSA, but still have significant improvements similar to those seen with aTSA. While the complication rate was higher for rTSA compared to aTSA, the rates are much lower than previously reported. This study provides physicians with information for advising patients what to expect following aTSA and rTSA.