Time to failure after rotator cuff repair: A prospective imaging study

Background: Failure of tendon healing after a rotator cuff repair is demonstrated by magnetic resonance imaging (MRI) as a fluid-filled defect within the tendon. The frequency of, and factors associated with, failure of the tendon repair to heal have been the focus of many clinical studies. The timing of when these defects occur has not been previously studied in a large prospectively defined patient population, to our knowledge. It was our hypothesis that the majority of failures occur within twelve weeks after surgery. Methods: One hundred and thirteen patients were enrolled in a multi-institutional prospective study. All patients had a standardized arthroscopic repair of a full-thickness tear of 1 to 4 cm as well as sequential MRI studies at six intervals from two weeks to fifty-two weeks. MRIs were reviewed at the time of imaging by the treating surgeon. Standardized patientoriented clinical data were collected, physical examination was performed, and strength measurements were made preoperatively and postoperatively. Results: The treating surgeons diagnosed a recurrent tear with MRI in nineteen (17%) of the 113 patients within one year after surgery. The mean time to the retear was 19.2 weeks. There was a linear increase in retears over the first twenty-six weeks after surgery, and one additional tear was diagnosed between twenty-six and fifty-two weeks after repair. Conclusions: Retears primarily occur between six and twenty-six weeks after arthroscopic rotator cuff repair, and few additional tears occur thereafter. A substantial number of retears occur between twelve and twenty-six weeks after repair. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.