Intraoperative Determinants of Rotator Cuff Repair Integrity

Abstract

Background: Rotator cuff repair has a relatively high (20%-90%) chance of retears. Patients with an intact rotator cuff 6 months after surgery have better subjective and objective outcomes at 6 months and 2 years after rotator cuff repair than those who do not have an intact repair. Purpose: The aim of this study was to determine if, and if so which, intraoperative factors predict an intact repair 6 months after rotator cuff repair. Study Design: Cohort study; Level of evidence, 3. Methods: The study consisted of a cohort of 500 consecutive patients who had an arthroscopic rotator cuff repair performed by a single surgeon and an ultrasound evaluation using standard protocols of the repair 6 months after surgery. Exclusion criteria included previous fracture or shoulder surgery, incomplete or partial rotator cuff repair, and concomitant arthroplasty. Rotator cuff tear size was measured intraoperatively and mapped. The quality of the tendon, tendon mobility, and repair quality were assessed and ranked based on predetermined scales (1-4) and recorded on a specifically designed form. Logistic regression analysis was performed, with cuff integrity at 6-month follow-up as the dependent variable and tear/repair factors as the independent variables. Results: The overall postoperative retear rate was 19% at 6 months. The best predictor of rotator cuff integrity was preoperative tear size (correlation coefficient, r = 0.33; P < .001). Patients with small (≤2 cm2) rotator cuff tears were least likely to have retears (retear rate, 10%). As the tear size increased, the retear rate increased in a linear fashion: ≤2 cm2 (10%), 2 to 4 cm2 (16%), 4 to 6 cm2 (31%), 6 to 8 cm2 (50%), and >8 cm2 (57%). Other surgeon-ranked intraoperative assessments did correlate with retears, but the correlations were relatively weak: repair quality ( r = −0.17; P < .001), tendon mobility ( r = −0.15; P < .001), and tendon quality ( r = −0.14; P < .01). Regression analysis showed that the retear rate at 6-month follow-up was best predicted from the preoperative tear size and the surgeon-ranked repair quality: chance of retear = 0.38 + (0.02 × tear size in cm2) – (0.08 × repair quality). Tendon quality and tendon mobility did not contribute significantly to this prediction. Conclusion: Tear size was the best intraoperative predictor of repair integrity after rotator cuff repair, with tears less than 2 cm2 twice as likely to heal than tears greater than 6 cm2.