“Are we doing too many margin convergence?” A Prospective MRI study on Rate of re-tear after arthroscopic rotator cuff repair

INTRODUCTION A prospective MRI study was conducted to examine the factors predicting retear after rotator cuff repair. METHODOLOGY 50 arthroscopic assisted complete repairs of full thickness supraspinatus tendon tear using double-row suture-bridge technique with post-operation reassessment MRI were studied. Retear was defined as Type IV or V repair according to Sugaya classification. Association of margin convergence with retear was studied by Chi square test. The potential association of re-tear and other known patient-related and cuff-related risk factors were examined. Significant association was assumed if p < 0.05. RESULT The incidence of full thickness retear was 38%. 10 patients received margin convergence. The incidence of retear after repair with margin convergence was 80% and that without was 28% (p=0.002). The other risk factors identified by univariate analysis to be significantly associated with retear was (1) large and massive tear (p=0.018); (2) increased number of full thickness tendon tear (p=0.03); (3) medial retraction of tear (p=0.001) and (4) Geometric classification of tear morphology (p=0.004). After mulivariate analysis, the most significant factor predicting retear after was medial retraction of tendon (p=0.048). The retear rate of Patte I, II and III were 24%, 50% and 100% respectively. CONCLUSION The most important factor predicting retear after rotator cuff repair was tear retraction in coronal plane. The use of margin convergence, despite helping to achieve a successful intraoperative complete repair, did not protect the repair from retear. The retear rate was 80%