Postoperative Patient-reported Outcomes and Radiographic Findings Do Not Significantly Change Between 1 and 2 Years Postoperatively After Primary Anatomic Shoulder Arthroplasty.

Background: It is unclear if there are significant changes in clinical and radiographic outcomes between 1 and 2 years postoperatively after total shoulder arthroplasty (TSA). The current multi-center study sought to compare patient-reported outcome measures (PROMs), range of motion (ROM) and radiographic analysis of glenoid and humeral loosening between one and two-years postoperatively in a cohort of patients after primary anatomic TSA (aTSA).

Methods: A retrospective cohort of patients who underwent primary anatomic TSA between 2017 and 2018 at two high-volume shoulder arthroplasty centers and had baseline, one and two-year PROMs were included in the study. The American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numerical Evaluation (SANE) scores were collected. Radiographs were evaluated at 1- and 2- years for humeral calcar resorption and glenoid component radiolucent lines and osteolysis.

Results: 211 patients were included. Median preoperative version was -5° [IQR -8;-2] and inclination was 6° [IQR 4;9]. There was no statistically significant difference between one and two-years total ASES score (92.6 [IQR 86.7;97.9] vs 95 [IQR 85;98.3], p = 0.71), ASES pain sub-score (50 [IQR 45;50] vs 50 [IQR 45;50], p = 0.05), SANE score (90 [IQR 83.5;98] vs 93 [IQR 85;98.3], p = 0.60) and external rotation (55° [IQR 50;60] vs 60° [IQR 50;60], p = 0.66). There was a statistically significant difference in the ASES function sub-score (43.3 [IQR 38.9;48.2] vs 46.3 [IQR 41.2;48.3], p = 0.03, respectively) and forward elevation (150° [IQR 135;160] vs 155° [IQR 143.8;165], p = 0.002). 145 of 211 (69%) patients had complete radiographic data. There was no statistically significant difference in the incidence of glenoid component osteolysis (3.4% vs 5.4%, p = 0.25), radiolucent lines (36.1% vs 29.9%, p = 0.15), or humeral calcar resorption (58.5% vs 49.7%, p = 0.06) between one and two years. There were 2 (0.9%) complications in the cohort, both of which occurred within the first 12 months postoperatively.

Conclusion: The present study demonstrates no changes in most PROMs and all measured radiographic findings between one and two-years postoperatively after primary aTSA. This data can help drive clinical decision-making with regards to the need for visits at both one and two years postoperatively for collection of PROMs, which add cost for the healthcare system and patients. Additionally, this may support lowering the minimum threshold required for reporting of "short term" follow-up in clinical research for aTSA.