Prognostic factors affecting structural integrity after arthroscopic rotator cuff repair: a clinical and histological study

Abstract

Background: Tendon degeneration contributes to rotator cuff tears; however, its role in postoperative structural integrity is poorly under-stood. The purpose of this study was to investigate the factors associated with postoperative structural integrity after rotator cuff repair, par-ticularly focusing on the histology of tendons harvested intraoperatively. Methods: A total of 56 patients who underwent primary arthroscopic rotator cuff repair between 2009 and 2011 were analyzed. A 3-mm-diameter sample of supraspinatus tendons was harvested en bloc from each patient after minimal debridement of the torn ends. Tendon degeneration was assessed using seven histological parameters on a semi-quantitative grading scale, and the total degeneration score was calculated. One-year postoperative magnetic resonance imaging was used to classify the patients based on retear. Results: The total degeneration scores in the healed and retear groups were 13.93±2.03 and 14.08±2.23 (P=0.960), respectively. Arthroscop-ically measured anteroposterior (AP) tear sizes in the healed and retear groups were 24.30±12.35 mm and 36.42±25.23 mm (P=0.026), re-spectively. Preoperative visual analog scale pain scores at rest in the healed and retear groups were 3.54±2.37 and 5.16±2.16 (P=0.046), re-spectively. Retraction sizes in the healed and retear groups were 16.02±7.587 mm and 22.33±13.364 mm (P=0.037), respectively. The odds of retear rose by 4.2% for every 1-mm increase in AP tear size (P=0.032). Conclusions: The postoperative structural integrity of the rotator cuff tendon was not affected by tendon degeneration, whereas the ar-throscopically measured AP tear size of the rotator cuff tendon was an independent predictor of retear. Level of evidence: III.