Defining Long-Term Success After Anatomic Total Shoulder Arthroplasty: Survivorship and Clinically Important Outcomes.

BACKGROUND

Long-term success after anatomic total shoulder arthroplasty (aTSA) is frequently defined by implant survivorship, but revision-free survival may not reflect durable clinical benefit.

METHODS

A retrospective cohort study of 791 consecutive aTSAs performed between 2003 and 2015 was conducted. Implant survivorship was assessed using Kaplan-Meier analysis. Clinical outcomes were evaluated at a 10-year landmark, and clinically important thresholds for the American Shoulder and Elbow Surgeons (ASES) score were derived using patient satisfaction as the anchor. Multivariable regression identified predictors of revision and substantial clinical benefit (SCB).

RESULTS

Kaplan-Meier survivorship was 96.1% at 10 years and 93.7% at 15 years. Walch B glenoid morphology and younger age were independently associated with revision. Clinical outcomes remained improved at long-term follow-up despite gradual attenuation over time. At 10 years, the patient acceptable symptom state (PASS) threshold for the ASES score was 68.1, and 69.5% of shoulders achieved it. The minimal clinically important difference (MCID) and SCB thresholds for the change in ASES score were 14.0 and 39.2, achieved by 79.9% and 55.8% of shoulders, respectively. Younger age, primary glenohumeral osteoarthritis, and lower preoperative ASES score were independently associated with achievement of SCB.

CONCLUSIONS

aTSA demonstrated excellent long-term implant survivorship and modest patient-reported outcomes, although shoulder function gradually attenuated over extended follow-up. Despite the gradual functional decline, most patients maintained clinically meaningful benefit at 10 years. Younger age and Walch B morphology increased revision risk. Long-term clinically important thresholds provide patient-centered benchmarks for defining durable success.

LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.