Collagen-Based Bioinductive Implant for Treatment of Partial Thickness Rotator Cuff Tears.

INTRODUCTION Partial thicknessrotator cuff tears(PTRCT) have low healing potential and tend to progress over time if not addressed surgically. There is a relative paucity of literature discussing optimal treatment for symptomatic PTRCT as compared to full thicknessrotator cuff tears. The available data supports a treatment course of debridement with or without acromioplasty for symptomatic patients with tears less than 50% in thickness combined with the use of repair (conversion to full thickness or transtendinous) for symptomatic patients with tears greater than 50% in thickness. The aim of this study was to evaluate functional and radiographic outcomes following surgical implantation of a collagen-based bioinductive implant for PTRCT. METHODS Patients with PTRCT who underwent implantation of a collagen-based bioinductive implant over the bursal surface of the rotator cuff were identified. Patients who had an implant placed to augment a standard full thickness repair were excluded from analysis. We administered questionnaires to patients with a minimum of 6 months since surgery and collected patient data including demographics, preoperative and postoperative American Shoulder and Elbow Society (ASES) scores, preoperative and postoperative visual analog scale (VAS) pain scores, complications, and satisfaction level. Magnetic resonance imaging (MRI) was obtained as needed, at 6 months, or at 12 months postoperatively, and tendon thickness was measured on coronal views. RESULTS Thirty patients were identified who met the inclusion and exclusion criteria. Twenty-four patients (80% response rate) were available for follow-up; 19 were male and five were female. Mean age and body mass index were 54.5 ± 11.6 years and 28.6 ± 5.9 kg/m2 , respectively. Mean tear thickness as measured intraoperatively was 56.6%. There were 16 (66.7%) articular-sided, five (20.8%) bursal-sided, and three (12.5%) intrasubstance tears. Mean survey follow-up time was 19.1 months. Mean ASES scores increased significantly from 45.6 preoperatively to 68.1 postoperatively (p = 0.001). Mean VAS pain scores decreased significantly from 8.3 preoperatively to 3.8 postoperatively (p < 0.001). Mean patient satisfaction level was 7.5. Ten patients had both a preoperative and postoperative MRI available for comparison. Tendon thickness at the tear site increased significantly from 5.7 mm preoperatively to 6.5 mm at mean 9.9 months follow-up (p = 0.007). There were no implant-related complications. One patient suffered a traumatic re-tear 4 months postoperatively. CONCLUSION Highly porous collagen-based bioinductive implants are safe and effective forreducing pain and improving shoulderfunction in patientswith PTRCT of approximately 50%, with radiographic evidence of new tissue formation. Randomized controlled trials are needed to assess efficacy relative to debridement and standard repair techniques.