Summary

Inlay total shoulder arthroplasty resulted in higher patient adoption of staged bilateral procedures than previously reported by national US claims databases.

Abstract

Background

Previous claims data from two national US databases with 27,962 total shoulder arthroplasties (TSA), reported an incidence of bilateral TSA of 6.3%. In our experience with inlay TSA since 2011, a higher proportion of patients decided to undergo the same procedure on the contralateral side. The purpose of this study was to investigate the functional and patient-reported outcomes in patients undergoing staged bilateral TSA with a non-spherical humeral head and inlay glenoid replacement for treatment of primary glenohumeral arthritis.

Methods

Patient-reported outcomes (PROs) included the American Shoulder and Elbow Surgeon’s (ASES) score, Western Ontario Osteoarthritis of the Shoulder (WOOS) Index, a visual analog scale for pain (VAS-Pain), and satisfaction. Clinical outcomes included range of motion and radiographic assessment. Preoperative radiographs were analyzed to determine the glenoid Walch classification. Last follow-up radiographs were evaluated for signs of radiolucency according to the Lazarus classification system.

Results

Our institutional shoulder arthroplasty database included 247 inlay TSA procedures performed between 8/2011 and 1/2020 which included 20.2% staged bilateral procedures (50 shoulders, 25 patients). The mean age was 66.2 years (29 male, 21 female shoulders), the minimum follow-up was 24 +/-2 months (mean 69 months, range 22-134 months). 92% had grade III osteoarthritis, and 8% grade II. The glenoid Walsh classification included A1 (24%), A2 (27%), B1 (24%), B2 (22%), and C (4%). 54% of shoulders had prospective baseline and follow-up PROs (Group 1) and 46% were evaluated at last follow-up only (Group 2). Similar baseline characteristics were shared between Group 1 and 2. Group 1 PROs improved significantly (p < .05) with a mean ASES from 22.9 to 77.0, WOOS from 1436 to 394, and VAS-Pain from 7.8 to 1.6. Group 2 patients showed similar outcomes with no statistically significant differences in PROs compared to Group1. Patient satisfaction was rated "excellent" in both groups a final follow-up (8.5/10). Range of motion improved from 101° degrees to 154° on forward elevation and 21° to 51° on external rotation in all patients. No blood transfusions were required, and no intra- or postoperative complications were encountered. Radiolucent lines were observed in 6% (3/50) of TSAs, with no gross component loosening.

Conclusion

Staged bilateral inlay TSA showed high patient satisfaction, significant pain relief and improvement on functional outcomes. Based on our results with this preliminary cohort, the patient decision-making process for contralateral TSA showed a higher incidence than previously reported for TSA and adds validation for this treatment option.