Radiologic and clinical evaluation of a bioabsorbable collagen implant to treat partial-thickness tears: a prospective multicenter study.

BACKGROUND: Treatment of partial-thickness cuff tears remains controversial. Although conservative therapy may treat symptoms, these defects do not spontaneously heal and conversion to a full-thickness lesion with subsequent repair may alter the tendon footprint. The ability to induce new tissue formation and limit tear progression in intermediate- and high-grade partial-thickness tears without surgical repair may represent a significant advancement in the treatment paradigm for these lesions.

METHODS: We prospectively enrolled 33 patients with chronic, degenerative, intermediate-grade (n = 12) or high-grade (n = 21) partial-thickness tears (11 articular, 10 bursal, 4 intrasubstance, and 8 hybrid) of the supraspinatus tendon in a multicenter study. Following arthroscopic subacromial decompression without repair, a bioinductive implant was attached over the bursal surface of the tendon. Clinical outcomes were assessed using American Shoulder and Elbow Surgeons and Constant-Murley scores preoperatively and at 3 and 12 months postoperatively. Magnetic resonance imaging was performed to assess postoperative tendon healing and thickness at the original tear site.

RESULTS: At 1-year follow-up, clinical scores improved significantly (P <.0001) and the mean tendon thickness increased by 2.0 mm (P <.0001). Magnetic resonance imaging evidence of complete healing was found in 8 patients and a considerable reduction in defect size was shown in 23, whereas 1 lesion remained stable. In 1 noncompliant patient with a high-grade articular lesion, progression to a full-thickness tear occurred while shoveling snow 1 month after surgery. No serious adverse events related to the implant were reported.

CONCLUSIONS: Arthroscopic implantation of a bioinductive collagen scaffold is a safe and effective treatment for intermediate- to high-grade partial-thickness rotator cuff tears of the supraspinatus tendon.