The recovery curve of anatomic total shoulder arthroplasty for primary glenohumeral osteoarthritis: midterm results at a minimum of 5 years

BACKGROUND: Excellent results have been reported for anatomic total shoulder arthroplasty (TSA) for the treatment of primary glenohumeral osteoarthritis (GHOA). We aim to assess the recovery curve and longitudinal effects of time, age, sex, and glenoid morphology on patient-reported outcomes (PROs) after primary anatomic TSA for primary GHOA. METHODS: Patients who underwent primary anatomic TSA over 5 years ago were included: Short-Form 12 Physical Component Summary, American Shoulder and Elbow Surgeons scores, Quick Disabilities of the Arm Shoulder and Hand Score, Single Assessment Numeric Evaluation, and patient satisfaction were assessed. Linear mixed-effects models were used to model progression in PROs longitudinally. Unadjusted models and models controlling for sex and age were constructed. RESULTS: Eighty-one patients (91 shoulders) were included. Significant improvements from the preoperative period to 1 year postoperatively in the median American Shoulder and Elbow Surgeons (48 to 93; P < .001), Quick Disabilities of the Arm Shoulder and Hand Score (42 to 11; P < .001), Single Assessment Numeric Evaluation (50 to 91; P < .001), and Short-Form 12 Physical Component Summary (35 to 53; P = .004) scores were noted. No significant decrease was observed for any of the outcome scores. Median satisfaction at the final follow-up was 10 out of 10. At 1, 2, 3, 4, 5, 6, and 7 years postoperatively, 77%, 64%, 79%, 57%, 86%, 56%, and 78% of patients, respectively, reported sports participation equal to or slightly below preinjury level. There was no association between the glenoid morphology and functional outcomes. CONCLUSION: Patients undergoing anatomic TSA for primary GHOA showed excellent improvement in PROs and satisfaction in the first year, and these results were maintained postoperatively for a minimum of 5 years. Age- and sex-adjusted models or glenoid morphology did not substantially alter any trends in PROs postoperatively.