Smith MJ, Cook JL, Kuroki K, Jayabalan PS, Cook CR, Pfeiffer FM, Waters NP, Smith, Matthew J, Cook, James L, Kuroki, Keiichi, Jayabalan, Prakash S, Cook, Cristi R, Pfeiffer, Ferris M, and Waters, Nicole P
Purpose: This study tested a bone-tendon allograft versus human dermis patch for reconstructing chronic rotator cuff repair by use of a canine model. Methods: Mature research dogs (N = 15) were used. Radiopaque wire was placed in the infraspinatus tendon (IST) before its transection. Three weeks later, radiographs showed IST retraction. Each dog then underwent 1 IST treatment: debridement (D), direct repair of IST to bone with a suture bridge and human dermis patch augmentation (GJ), or bone-tendon allograft (BT) reconstruction. Outcome measures included lameness grading, radiographs, and ultrasonographic assessment. Dogs were killed 6 months after surgery and both shoulders assessed biomechanically and histologically. Results: BT dogs were significantly (P = .01) less lame than the other groups. BT dogs had superior bone-tendon, tendon, and tendon-muscle integrity compared with D and GJ dogs. Biomechanical testing showed that the D group had significantly (P = .05) more elongation than the other groups whereas BT had stiffness and elongation characteristics that most closely matched normal controls. Radiographically, D and GJ dogs showed significantly more retraction than BT dogs (P = .003 and P = .045, respectively) Histologically, GJ dogs had lymphoplasmacytic infiltrates, tendon degeneration and hypocellularity, and poor tendon-bone integration. BT dogs showed complete incorporation of allograft bone into host bone, normal bone-tendon junctions, and well-integrated allograft tendon. Conclusions: The bone-tendon allograft technique re-establishes a functional IST bone-tendon-muscle unit and maintains integrity of repair in this model. Clinical Relevance: Clinical trials using this bone-tendon allograft technique are warranted. [ABSTRACT FROM AUTHOR]