The effects of obesity on 1-year functional outcomes after arthroscopic rotator cuff tear repair

BACKGROUND: The purpose of our study was to examine the impact that an increased body mass index (BMI) has on arthroscopic rotator cuff repair (aRCR) outcomes. METHODS: We identified a sample of 313 patients who underwent aRCR at our institution from 2017 to 2020. Patients were classified into cohorts by BMI: normal BMI (<25), overweight (25-30), and obese (≥30). Patient-Reported Outcomes Measurement Information System (PROMIS) scores (Pain Interference, Pain Intensity, and Upper Extremity) and Clinical Global Impressions scale rating of pain and functional improvement after surgery were obtained at 1 year postoperatively. The significance of the BMI category as a predictor for outcomes was evaluated using multiple linear and multivariable logistic regressions. Receiver operating characteristic curve analysis with Youden’s J-statistic was used to determine optimal BMI cutoff for predicting likelihood of achieving minimum clinically important difference (MCID) and substantial clinical benefit (SCB) on the Clinical Global Impressions scales. RESULTS: Obesity was a significant predictor of reduced preoperative-to-postoperative improvement in the PROMIS Upper Extremity score (P = .04). However, BMI was not predictive of other preoperative-to-postoperative differences in outcome scores or the size and number of cuff tendons torn (P > .05). Optimal BMI cutoffs were determined for pain MCID (40.8), pain SCB (26.8), function MCID (27.4), and function SCB (26.8), but all cutoffs had low correct classification rates (≤13%). DISCUSSION AND CONCLUSION: Obesity was not found to be an independent risk factor for increased rotator cuff tear size or tendon involvement but was nonetheless associated with worse upper extremity function and pain after aRCR.