Critical shoulder angle does not influence retear rate after arthroscopic rotator cuff repair

Purpose The critical shoulder angle (CSA) has been implicated as a potential risk factor for failure following arthroscopic rotator cuff repair (RCR). However, there is conflicting evidence regarding the clinical usefulness of this measurement. Given these discrepancies and limited comparisons to clinical outcomes, the aim of the current study was to determine whether higher CSAs correlated with an increased retear rate after arthroscopic rotator cuff repair and to determine if any association between CSA and patient-reported outcomes (PROs) exists. It was hypothesized that there would be no correlation between CSA and retear rate or PROs after arthroscopic rotator cuff repair. Methods A total of 164 patients who underwent arthroscopic RCR were retrospectively reviewed. CSA was measured for each patient. Patients were then divided into a retear group of 18 patients and a non-retear group of 146 patients. Patient-reported outcomes (PROs), including PROMIS 10 score, American Shoulder and Elbow Surgeons (ASES) score, Brophy score, and visual analog pain scores (VAS) were recorded post-operatively. Results The average CSA was 31.2 +/- 4.5 degrees for the retear group and 32.2 +/- 4.7 degrees for the non-retear group (n.s.). No correlations were found between CSA and PROMIS score (n.s.), ASES score (n.s.), Brophy score (n.s.), or VAS (n.s.). Conclusion Critical shoulder angle had no correlation to retear rate or patient-reported outcomes. CSA should not be used as a clinical predictor to assess rotator cuff retear risk after arthroscopic RCR.