Factors affecting healing rates after arthroscopic double-row rotator cuff repair.

Background: Double-row arthroscopic rotator cuff repairs were developed to improve initial biomechanical strength of repairs to improve healing rates. Despite biomechanical improvements, failure of healing remains a clinical problem.
Purpose: To evaluate the anatomical results after double-row arthroscopic rotator cuff repair with ultrasound to determine postoperative repair integrity and the effect of various factors on tendon healing.
Study Design: Case series; Level of evidence, 4.
Methods: Forty-eight patients (49 shoulders) who had a complete arthroscopic rotator cuff repair (double-row technique) were evaluated with ultrasound at a minimum of 6 months after surgery. Outcome was evaluated at a minimum of 1-year follow-up with standardized history and physical examination, visual analog scale for pain, active forward elevation, and preoperative and postoperative shoulder scores according to the system of the American Shoulder and Elbow Surgeons and the Simple Shoulder Test. Quantitative strength was measured postoperatively.
Results: Ultrasound and physical examinations were performed at a minimum of 6 months after surgery (mean, 16 months; range, 6 to 36 months) and outcome questionnaire evaluations at a minimum of 12 months after surgery (mean, 29 months; range, 12 to 55 months). Of 49 repairs, 25 (51%) were healed. Healing rates were 67% in single-tendon tears (16 of 24 shoulders) and 36% in multitendon tears (9 of 25 shoulders). Older age and longer duration of follow-up were correlated with poorer tendon healing (P < .03). Visual analog scale for pain, active forward elevation, American Shoulder and Elbow Surgeons scores, and Simple Shoulder Test scores all had significant improvement from baseline after repair (P < .0001).
Conclusion: Increased age and longer duration of follow-up were associated with lower healing rates after double-row rotator cuff repair. The biological limitation at the repair site, as reflected by the effects of age on healing, appears to be the most important factor influencing tendon healing, even after maximizing repair biomechanical strength with a double-row construct.