Medial rotator cuff failure after arthroscopic double-row rotator cuff repair.

Persistent tendon defects after rotator cuff repair are not uncommon. Recently, the senior author has identified a subset of 5 patients (mean age, 52 years; range, 42 to 59 years) after arthroscopic double-row rotator cuff repair who showed an unusual mechanism of tendon failure. In these patients the tendon footprint appears well fixed to the greater tuberosity with normal thickness. However, medial to the intact footprint, the tendon is torn with full-thickness defects through the rotator cuff. All patients were involved in Workers' Compensation claims. Magnetic resonance arthrography showed an intact cuff footprint but dye leakage in all patients. Revision surgery was performed at a mean of 8.6 months after the index procedure and showed an intact rotator cuff footprint but cuff failure medial to the footprint. Four patients had repair of the defects by tendon-to-tendon side-to-side sutures, whereas one did not undergo repair. Medial-row failure of the rotator cuff is a previously unreported mechanism of failure after double-row rotator cuff repair. Given the small number of patients in this study, it is unclear whether these defects are symptomatic. However, repair of these defects resulted in improvement in pain in 4 of 5 patients.