Long-term clinical and radiographic outcomes of total shoulder arthroplasty in patients under age 60 years

Background: We aimed to characterize the long-term clinical and radiographic outcomes of total shoulder arthroplasty (TSA) in patients aged < 60 years. We hypothesized meaningful improvements in shoulder functionality and pain with TSA and an acceptably low rate of prosthesis complications and revisions. Methods: This was a retrospective cohort study of 29 patients (34 shoulders) undergoing TSA before age 60 years with a minimum follow-up period of 10 years. Shoulder range of motion, functionality (American Shoulder and Elbow Surgeons and Simple Shoulder Test scores), and pain (visual analog scale score) were evaluated. Radiographs were assessed for lateral humeral offset, the acromiohumeral interval, and glenoid loosening. Results: The mean age of the patients was 54.4 ± 5.5 years (range, 35.5-59.8 years), with a mean follow-up period of 16.1 ± 4.5 years (range, 10.0-26.1 years). In patients aged < 60 years, TSA significantly improved forward elevation (from 119° ± 26° to 146° ± 21°, P =.0002), external rotation (from 21° ± 25° to 52° ± 15°, P =.0001), and internal rotation (from L5 to L1, P =.002). Additionally, TSA significantly increased American Shoulder and Elbow Surgeons scores (from 32 ± 20 to 64 ± 27, P =.0008) and Simple Shoulder Test scores (from 3 ± 2 to 7 ± 4, P =.0004) and reduced visual analog scale pain scores (from 7 ± 3 to 3 ± 3, P =.0001). Radiographically, there was no significant difference in mean lateral humeral offset (13 ± 6 mm vs. 10 ± 12 mm, P =.472) or the mean acromiohumeral interval (20 ± 4.2 mm vs. 16 ± 6 mm, P =.061) between immediate postoperative and final follow-up radiographs. Radiographic evidence of glenoid loosening was noted in 2 patients. Complications occurred in 6 patients (17.6%), all of which were cases of aseptic glenoid loosening. Ultimately, 4 patients underwent conversion to a reverse TSA and 2 underwent arthroscopic glenoid removal. The rate of prosthesis survivorship was 97.1% (95% confidence interval [CI], 91.4%-100%) at 10 years, 85.4% (95% CI, 73.7%-97.2%) at 15 years, and 80.1% (95% CI, 65.1%-98.4%) at 20 years. Discussion: TSA consistently improved shoulder functionality and reduced pain while limiting the need for further revisions. These findings suggest that TSA is a viable treatment option for glenohumeral arthritis in younger patients.