Influence of Preoperative Musculotendinous Junction Position on Rotator Cuff Healing After Double-Row Repair.
OBJECTIVE
The primary purpose of this study was to determine the effect of the preoperative position of the musculotendinous junction (MTJ) on rotator cuff healing after double-row arthroscopic rotator cuff repair. A secondary purpose was to evaluate how tendon length and MTJ position change when the rotator cuff heals.


METHODS
Preoperative and postoperative magnetic resonance imaging (MRI) scans of 42 patients undergoing arthroscopic double-row rotator cuff repair were reviewed. Patients undergoing repairs with other constructs or receiving augmented repairs (platelet-rich fibrin matrix) who had postoperative MRI scans were excluded. Preoperative MRI scans were evaluated for anteroposterior tear size, tendon retraction, tendon length, muscle quality, and MTJ position with respect to the glenoid in the coronal plane. The position of the MTJ was referenced off the glenoid face as either lateral or medial. Postoperative MRI scans were evaluated for healing, tendon length, and MTJ position.


RESULTS
Of 42 tears, 36 (86%) healed, with 27 of 31 small to medium tears (87%) and 9 of 11 large to massive tears (82%) healing. Healing occurred in 94% of tears that had a preoperative MTJ lateral to the face of the glenoid but only 56% of tears that had a preoperative MTJ medial to the glenoid face (P = .0135). The measured tendon length increased an average of 14.4 mm in patients whose tears healed compared with shortening by 6.4 mm in patients with tears that did not heal (P < .001). The MTJ lateralized an average of 6.1 mm in patients whose tears healed compared with medializing 1.9 mm in patients whose tears did not heal (P = .026). The overall follow-up period of the study was from April 2005 to September 2014 (113 months).


CONCLUSIONS
The preoperative MTJ position is predictive of postoperative healing after double-row rotator cuff repair. The position of the MTJ with respect to the glenoid face is a reliable, identifiable marker on MRI scans that can be predictive of healing.


METHODS
Level IV, retrospective review of case series; therapeutic study.
Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.. Electronic address: Robert.Tashjian@hsc.utah.edu.
Robert Z
RZ
Tashjian
Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.
Gregory A
GA
Erickson
Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.
Richard J
RJ
Robins
Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.
Yue
Y
Zhang
Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.
Robert T
RT
Burks
Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, Utah, U.S.A.
Patrick E
PE
Greis
D000328:Adult; D001182:Arthroscopy; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D017006:Rotator Cuff / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D000070636:Rotator Cuff Injuries / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D013536:Suture Techniques; D016896:Treatment Outcome; D014945:Wound Healing