Improved Acromiohumeral Distance Independently Predicts Better Outcomes After Arthroscopic Superior Capsular Reconstruction Graft Tears

PURPOSE: To identify independent factors responsible for the poor outcomes after a graft tear after arthroscopic superior capsular reconstruction (ASCR).

METHODS: Patients who underwent ASCR for massive rotator cuff tears between January 2013 and July 2021were reviewed. Based on the achievement of the minimal clinically important differences for clinical outcome measures at the final follow up, patients were divided into the good outcome (GO) and poor outcome (PO) groups. The minimal clinically important differences were calculated as the values equal to one-half of the standard deviation of the changes in outcome scores between the preoperative baseline and the latest follow-up. Pre- and final follow-up variables included demographics, American Shoulder and Elbow Surgeons (ASES) score, Constant score, visual analog scale (VAS) score, range of motion, Preoperative and postoperative 1-year radiological variables were analyzed using MRIs, including anteroposterior (AP) and mediolateral (ML) tear sizes, subscapularis tear, acromiohumeral distance (AHD), and degree of fatty degeneration. Logistic regression analysis was performed to identify the significant predictors of poor outcomes.

RESULTS: A total of 33 patients who underwent ASCR presented with graft tears, which were confirmed by postoperative 1-year magnetic resonance imaging (MRI), and had a minimum follow-up duration of 2 years after surgery were enrolled. The GO group demonstrated significantly greater improvements in functional outcomes compared with the PO group (ASES: 83.5 ± 11.8 vs. 64.0 ± 20.4, P = 0.004; Constant: 67.6 ± 5.7 vs. 57.1 ± 9.8, P <0.001; and VAS: 0.9 ± 1.2 vs. 2.4 ± 2.0, P = 0.026). The postoperative 1-year AHD showed significant improvement in the GO group (3.1 ± 1.2 vs. 6.1 ± 1.4, P <0.001) but no change in the PO group (3.4 ± 1.3 vs. 4.2 ± 0.9, P = 0.074) postoperatively. Multivariate logistic regression analysis indicated that a decreased postoperative 1-year AHD (OR, 0.145; P = 0.019) was associated with a poor outcome after a graft tear.

CONCLUSION: A narrow postoperative 1-year AHD was identified as the most importantindependent risk factor indicating poor clinical outcomes after a graft tear post-ASCR, which was related to a larger tear and loss of integrity between the grafts and infraspinatus at 1 year postoperatively.

LEVEL OF EVIDENCE: Level IV.