Hypothyroidism Increases Risk of 90-Day and 1-Year Complications After Primary Rotator Cuff Repair: A Retrospective Cohort Study

Purpose: Rotator cuff repair (RCR) is a commonly performed orthopedic procedure with generally favorable outcomes. However, the influence of systemic conditions such as hypothyroidism on postoperative complications remains underexplored. This study aimed to evaluate the impact of hypothyroidism on short- and long-term outcomes following primary RCR. Methods: A retrospective cohort study was conducted using data from the TriNetX Research Network, comprising over 100 healthcare organizations. Patients undergoing primary RCR between April 2005 and April 2024 were included. Hypothyroid patients were identified by a documented diagnosis within one week before surgery and matched 1:1 to euthyroid controls using propensity score matching based on demographics and comorbidities. Postoperative complications were assessed at 90 days and 1 year. Results: The final matched cohort included 7,647 patients in both cases and controls. At 90 days, hypothyroid patients had significantly higher rates of pulmonary embolism, deep vein thrombosis, acute kidney injury, urinary tract infections, fracture, shoulder stiffness, and postoperative pain. At 1 year, increased risks persisted for pulmonary embolism, deep vein thrombosis, acute kidney injury, urinary tract infections, fracture, shoulder stiffness, postoperative pain, sepsis, and shoulder replacement. Conclusion: Hypothyroidism is associated with increased postoperative complications following RCR, including higher rates of thromboembolic, renal, and musculoskeletal issues, as well as a greater likelihood of shoulder replacement. Preoperative identification and management of hypothyroidism may be crucial in optimizing surgical outcomes in this population.