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

Introduction: Partial thickness rotator 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 thickness rotator 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 El-bow 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/m(2), respectively. Mean tear thickness as measured intraoperatively was 56.6%. There were 16 (66.7%) articular-sided, five (20.8%) bursal-sided, and three 02.5%) intrasubstance tears. Mean survey Plow-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 for reducing pain and improving shoulder function in patients with 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.