Atelocollagen Injection During Arthroscopic Rotator Cuff Repair for Small to Medium-Sized Subacute or Chronic Rotator Cuff Tears Enhances Radiographic Tendon Integrity: A Propensity Score-Matched Comparative Study.

Purpose To evaluate the clinical and structural outcomes of using injectable atelocollagen during arthroscopic rotator cuff repair (ARCR) for small to medium-sized rotator cuff tears. Methods This retrospective study reviewed patients with small to medium size full-thickness tears who underwent ARCR from 2016 to 2022 with minimum 1 year follow-up. Propensity score (PS) matching was used to reduce bias. Tendon integrity was evaluated using magnetic resonance imaging (MRI) at postoperative 6 months. Clinical and structural outcomes were compared between the two groups. Results After PS matching, this study included 181 pairs of patients comparing ARCR with atelocollagen injection and without atelocollagen injection. Range of Motion, muscle strength, and functional outcomes were significantly improved in both the atelocollagen group and the control group. Forward elevation and external rotation were significantly worse in the atelocollagen group compared to the control group at 2, 6, 12 months postoperatively and at final follow-up. 125 patients (69.1%) in the atelocollagen group and 130 patients (71.8%) in the control group exceeded the MCID in ASES score without significant difference between the two groups (P = .509). The mean value of Sugaya grade on postoperative MRI evaluation was 2.03 ± 0.81 for the atelocollagen group and 2.24 ± 0.97 for the control group with a significant difference between the two groups (P = .027). Tendon healing failure was observed in 12 patients (6.6%) in the atelocollagen group and 19 patients (10.5%) in the control group with no statistical difference between the two groups (P = .189). Conclusion Atelocollagen injection during arthroscopic rotator cuff repair for small- to medium-sized subacute or chronic rotator cuff tears did not show benefit in clinical outcomes. However, postoperative MRI showed significantly lower Sugaya grade compared to the control group, with no significant difference in retear rate. Level of evidence III, Retrospective case-control study