Influence of Preoperative Musculotendinous Junction Position on Rotator Cuff Healing After Double-Row Repair


      The purpose of this study was to determine the effect of the preoperative position of the musculotendinous junction (MTJ) on rotator cuff repair healing after double-row repairs.


      Preoperative and postoperative MRIs were reviewed of 42 patients undergoing arthroscopic double-row rotator cuff repair. Preoperative MRIs were evaluated for anteroposterior tear size, tendon retraction, tendon length, muscle quality, and MTJ position with respect to the glenoid. The position of the MTJ was referenced off the glenoid face as either lateral or medial. Postoperative MRIs were evaluated for healing, tendon length, and MTJ position.


      36 of 42 tears (86%) healed, with 27 of 31 small/medium tears (87%) and 9 of 11 large/massive tears (82%) healing. Repairs that failed to heal did have a significantly more medialized preoperative MTJ position (1.3 mm vs. 9.9 mm lateral to the glenoid, p = 0.033). 94% of tears that had a preoperative MTJ lateral to the face of the glenoid healed, while only 56% of tears that had a preoperative MTJ medial to the face of the glenoid healed (p=0.0135). Results from univariate regression analysis indicated that a preoperative MTJ medial to the glenoid face was correlated with worse tendon healing (p=0.047). The measured tendon length increased an average of 14.4 mm in patients who healed compared to shortening 6.4 mm in patients that did not heal (p<0.001). The MTJ lateralized an average of 6.1 mm in patients who healed compared to medializing 1.9 mm in patients who did not heal (p=0.026).


      Preoperative MTJ position is predictive of postoperative tendon healing after double-row rotator cuff repair. The glenoid face can be used as a marker to reference MTJ position and predict postoperative healing rates. If the tendon heals, healing typically occurs with some tendon lengthening and some MTJ lateralization.