Prediction of Rotator Cuff Repair Failure by Histological Analysis

Background We aimed to determine if recognised histological features seen in specimens taken during rotator cuff repair could predict which tendon repairs were at risk of re-rupture. Methods Forty rotator cuff tendon edge specimens from 40 patients were analysed histologically following routine mini-open rotator cuff repair. Thirty-two patients returned at a mean follow up of 35 months for an ultrasound examination to determine repair integrity. Results Overall there were 8 small tears, 13 medium tears, 15 large tears and 4 massive tears. Of the 32 patients followed up with ultrasound scan (USS) the overall re-rupture rate was 46%. Small and medium tears had a re-rupture rate of 35% while 60% of the large and massive tears suffered a re-rupture. Comparison of histological features and repair integrity revealed that the rotator cuff repairs which remained intact demonstrated a greater reparative response, in terms of increased fibroblast cellularity, cell proliferation and a thickened synovial membrane, than those repairs that re-ruptured. The larger tears that did remain intact also showed a higher degree of vascularity and a significant inflammatory component than the larger tears that re-ruptured. Conclusion These results indicate the importance of good tissue quality at the time of surgery but that larger tears can heal if the tissue quality is favourable. Post-operative histological analysis of tendon tear edge can aid prognosis and has the potential to guide post-operative immobilization and subsequent physiotherapy.