High Repair Tension and Advanced Age Negatively Affect Subscapularis Healing Status Following Arthroscopic Rotator Cuff Repair.

Purpose: The study aim to (1) investigate the relationship between repair tension and radiological outcomes, and (2) identify cutoff values of associated factors that predict both radiological and clinical outcomes following arthroscopic subscapularis (SSC) repair.

Methods: This retrospective study included patients who underwent SSC repair and completed a 2-year follow-up between September 2020 and March 2022. Intraoperative evaluations examined the retraction length, repaired tendon, and Lafosse's classification. Magnetic resonance imaging was performed before surgery and 6 months postoperatively to evaluate the severity of the tear, fatty infiltration, and healing status of the SSC and supraspinatus Functional scores and internal rotation strength were measured before surgery and at 6, 12, and 24 months postoperatively. Multiple logistic regression identified variables associated with poor healing, with receiver operating characteristic curves determining cutoff values.

Results: A total of 67 patients was included. The mean SSC repair tension was 3.72 ± 1.48 kg. Poor healing was observed in 25.4% of the patients, with significant differences in age (p = 0.004), repair tension (p = 0.002), retraction length (p = 0.033), and Lafosse's classification (p = 0.035) observed between the adequate and poor healing groups. Multiple logistic regression revealed significantly increased odds ratios (ORs) for poor SSC healing in patients over 65 years and in those with repair tension exceeding 4 kg for poor SSC healing.

Conclusion: Poor SSC healing is associated with advanced age, increased repair tension, greater retraction length, and more severe Lafosse classification. Patients over the age of 65 and those with a repair tension exceeding 4 kg are at a significantly higher risk of poor SSC healing. Furthermore, patients with poor SSC healing exhibit significantly reduced internal rotation strength at 24 months postoperatively. However, no significant decline was observed in shoulder function scores or in the achievement of minimal clinically important difference.

Study design: Retrospective cohort study; Level of evidence, 3.