Clinical and Radiologic Outcomes of Bioinductive Collagen Implant Augmentation in Sugaya Type III Rotator Cuff Retears.

Background: Sugaya type III rotator cuff re-tears are characterized by preserved tendon continuity with reduced thickness and are often associated with persistent pain and functional impairment. Bioinductive collagen implants may enhance tendon healing, but clinical evidence in this population remains limited. This study aimed to evaluate the clinical and radiologic outcomes of arthroscopic repair with bioinductive collagen implant augmentation in patients with Sugaya type III re-tears. Methods: This retrospective case series (Level IV) included 15 patients (mean age 61.7 years) with MRI-confirmed Sugaya type III re-tears. An a priori power analysis based on a large effect size (Cohen's d = 0.80) indicated that a sample size of 15 would provide 80% power to detect clinically meaningful changes in the primary endpoint. Clinical outcomes were assessed preoperatively and at 6 and 12 months postoperatively using VAS, ASES, SANE, and WORC scores. MRI was used to evaluate changes in supraspinatus tendon thickness. Non-parametric statistical analysis with Bonferroni correction was applied. Results: The median VAS pain score improved from 6.5 (IQR, 6.0-7.0) preoperatively to 2.8 (IQR, 2.0-3.5) at 6 months and to 2.1 (IQR, 1.5-2.8) at 12 months (adjusted p < 0.001). The median ASES score increased from 45.0 (IQR, 39.0-51.0) to 78.0 (IQR, 72.0-85.0), with a median improvement of 33 points. SANE and WORC scores also showed significant improvements. Supraspinatus tendon thickness increased from 4.8 mm (IQR, 3.7-5.7) to 6.9 mm (IQR, 5.4-8.3) at 12 months (adjusted p < 0.001). No graft failure was observed on follow-up MRI. Conclusions: Arthroscopic repair with bioinductive collagen implant augmentation may be associated with short-term improvements in pain, function, and tendon thickness in patients with Sugaya type III re-tears. Given the small sample size and lack of a control group, these findings should be interpreted cautiously, and further prospective comparative studies are needed.