Rotator cuff tears are a common problem and the overall number of patients affected is increasing as our population continues to age. As the number of rotator cuff tears rises, the incidence of large and massive rotator cuff tears requiring surgery will also increase. Despite a comprehensive understanding of the rotator cuff and biomechanical the advanced surgical repair techniques, there is still a subset of rotator cuff tears that go on to failure. Outcomes following repair of these rotator cuff tears depend on factors such as tear size, chronicity of the tear, patient age and muscle atrophy. Long-term data show that anatomic healing of rotator cuff tears produces better outcomes.
Failure of anatomic repairs is reportedly 20 to 40% after primary rotator cuff repairs and can be higher in revision cases.
The mechanical properties of repaired rotator cuff tissue are significantly reduced as compared with the native tendon. Instead of trying to compensate for poor tendon quality with structural support, newer technology has been developed to promote tendon vascularization and growth. The Rotation Medical bioinductive implant is a nonstructural, highly porous collagen scaffold made from highly purified type I bovine collagen. The scaffold has a weak tensile strength and provides no structural support. It is designed to induce collagen formation and remodeling of the damaged tissue, leading to an increased overall thickness of the healed tendon. The patch provides the framework for the tendon to heal with increased thickness and strength. Research suggests that added thickness decreases the strain and stress of the tendon decreasing the risk of failure of rotator cuff repair.
In research models, the implant induces the formation of new tendon that consisted of collagen fibrous well organized in the direction of load. The patch was found to completely incorporate by 6 months and no adverse foreign body reactions have been reported to date. Approximately 2.5 mm of additional tissue was induced from the patch in studies compared with controls. The new tissue was well integrated into the native rotator cuff and showed fibrocartilaginous transition from tendon to bone.
In human trials, the bioinductive collagen patch has been applied to the bursal side of the rotator cuff during repair. In the patients studied over 24 months, serial MRIs were obtained with no failures occurring during that time frame. By 3 months, all patients had an implant induced tissue formation with an additional 2 mm of new tissue reported at final follow-up.
In another study, the nonstructural bioinductive collagen patch was placed over intermediate to high-grade partial thickness rotator cuff tears without performing a repair. By 3 months, all patients showed new tissue formation averaging 2.2 mm of increased tendon thickness. Of 13 patients in this study, 7 had complete tendon healing with the rest demonstrating no progression of the tears. The 2 mm of increased bursal cuff thickness has been proposed to reduce stress within the damaged tendon and provide an environment that allows for tendon to bone healing. Additional studies demonstrated improved outcome scores and 94% of patients with either no progression of tears or a reduction in defect size after 1 year.
Early results in small groups of patients have shown evidence of healing and partial thickness rotator cuff tears and medium-sized rotator cuff tears with excellent healing rates and results.
This particular study looked at patients with large (2 tendon) and massive (3 tendon) rotator cuff tears. Patients were included in the study if they were over 30 years of age with a large or massive rotator cuff tear. Patients with a large or massive rotator cuff tear measuring over 3 cm and with retraction of at least 3 cm were considered for the study. Exclusionary criteria included patients under 30 years of age, significant muscular atrophy and fatty infiltration of the rotator cuff muscle due to a chronic tear and lack of follow-up of at least 2 years.
All patients with large, massive or retracted rotator cuff tears or those undergoing revision procedures have a capsular release performed during the procedure. This consists of a 360-degree capsular release, release of coracohumeral ligament and, in tears with significant retraction greater than 3 to 5 cm, an arthroscopic suprascapular nerve decompression. Surgery included extensive debridement and releases with subacromial or subcoracoid decompression or distal clavicle excision, biceps tendon treatment and suprascapular nerve decompression as indicated in each case.
The Rotation Medical collagen bioinductive patch is placed directly onto the repaired tendon fixed by absorbable and nonabsorbable anchors on each end of the graft.
Postoperatively, each patient’s arm was placed in an abduction pillow sling for 6 to 8 weeks. Scapular retraction exercises were started postoperative day 1. The abduction pillow was worn at all times including sleep for 6 to 8 weeks. Only passive range of motion was allowed for the first 4 to 8 weeks. After 8 weeks the patient’s began progressive active range of motion. Once active range of motion and return to 85 to 90% of the unaffected extremity, the patients were allowed to start light strengthening exercises. This most commonly began at 16 weeks post op. In general, patients are advised that the affected extremity would only reach 80% of the function of the unaffected extremity.
There are 23 patients who completed the study protocol. Their mean age was 58 years old. Of the 23 patients, 16 underwent revision rotator cuff repair versus 7 primary repairs. 11 of the 23 had a large rotator cuff tears (2 tendon tears) on 12 patients had massive rotator cuff tears (3 tendon tears).
Patients underwent postoperative MRIs and ultrasounds to evaluate the integrity of the rotator cuff repair in the thickness of the rotator cuff tendon.
The tendon healing rate on both ultrasound and MRI imaging modalities was 96%. 22 of the 23 rotator cuff tears healed in its entirety.
The Rotation Medical bioinductive patch used in this study is purified, very porous bovine collagen. Studies have not demonstrated any rejection or foreign body reactions.
A recently published multicenter study showed excellent results and stimulating healing response in partial thickness tears. Imaging consistently showed formation of new tendon tissue.
This study reveals that the arthroscopic application of a bioinductive collagen patch in the setting of large and massive rotator cuff tears may provide benefits to healing these difficult repairs. Postoperative ultrasound scans demonstrate increases in tendon thickness as far out is 12 months. The implant is designed to stimulate collagen formation and tissue healing and to improve vascularity. It has been shown to provide excellent tissue formation and integration in partial rotator cuff tears and single tendon tears. Collagen scaffold helps to increase the tendon thickness and vascularity in large and massive tears as well.
In revision rotator cuff repairs, healing rates can be of this low as 60 to 80%. This study demonstrated a healing rate of 96% in a combination of large and massive tears including revision rotator cuff repairs in 16 of the 23 patients.
Evaluation of Healing Rates and Safety with a Bioinductive Collagen Patch for Large and Massive Rotator Cuff Tears. American Journal of Sports Medicine. 2019