Poster 183: Preoperative Shoulder Osteoarthritis Severity (SOAS) Score Predicts Change in ASES Scores at 2 Years Following Rotator Cuff Repair

OBJECTIVES: Patients with rotator cuff (RC) tears are frequently found to have mild-to-moderate glenohumeral osteoarthritis (GHOA), but the association between radiographic findings of GHOA and PROs following RC repair (RCR) is not well established. The shoulder osteoarthritis severity score (SOAS) has previously been found to correlate with changes in ASES scores following total shoulder arthroplasty in patients with glenohumeral osteoarthritis (GHOA). We have also previously found that higher preoperative SOAS scores predicted lower PROMIS-UE scores following RCR. The purpose of this study was to apply the SOAS scoring system to a larger, prospectively collected cohort of patients that underwent RCR with pre-operative ASES scores and post-operative scores obtained at least 2 years following surgery and determine whether a correlation exists between pre-operative SOAS scores and changes in ASES scores. METHODS: Patients who underwent primary rotator cuff repair with at least 24 months follow-up with pre-operative MRI and pre- and post-operative ASES scores were included in the study. One hundred and sixteen MRIs corresponding to 116 patients were analyzed by two independent reviewers and scored according to the SOAS criteria. Intraclass correlation coefficients (ICCs) were calculated for total SOAS score and for each sub-score. Spearman’s correlations were calculated between averaged SOAS scores, patient demographics, and the change in ASES scores over the follow-up period. Multivariate regressions were performed between the independent variables of patient age, sex, BMI, and significant SOAS score components determined by univariate analysis with the dependent variable of delta ASES scores. All statistical analyses were performed with STATA. Significance was defined as p<0.05. RESULTS: The mean preoperative ASES score was 55.8 ± 18.6, while postoperative scores at 2 years averaged 92.1 ± 12.1 (Table 1). The average preoperative SOAS score was 15.2 ± 7.1 (Table 2). Intraclass correlation coefficient (ICC) for total SOAS score was 0.87 (Table 2). There was a negative correlation between preoperative SOAS score and change in ASES score at 2 years (r = -0.22, p = 0.015) (Table 3). Supraspinatus/infraspinatus tear size, tendon retraction, muscle atrophy, paralabral ganglia, and cartilage degeneration all significantly negatively correlated with change in ASES scores (Table 3). Tear size, tendon retraction, and paralabral ganglia were independent negative predictors of delta ASES score in multivariate linear regressions with patient age, sex, and BMI (Table 4). CONCLUSIONS: In this prospective cohort of patients undergoing RCR, increasing pre-operative total SOAS score was predictive of less improvement in ASES scores at 2 years after surgery. SOAS sub-scores with the strongest negative correlations with change in ASES scores included tear size, muscle atrophy, tendon retraction, paralabral ganglia, and cartilage wear.