Biomechanical Comparison of Augmentation of Engineered Tendon-Fibrocartilage-Bone Composite With Acellular Dermal Graft Using Double Rip-Stop Technique for Canine Rotator Cuff Repair

Abstract

Background: The retear rate after rotator cuff repair remains unacceptably high. Various biological engineered scaffolds have been proposed to reduce the retear rate. We have developed a double rip-stop repair with medial row knot (DRSK) technique to enhance suture-tendon strength and a novel engineered tendon-fibrocartilage-bone composite (TFBC) for rotator cuff repair. Hypothesis: DRSK rotator cuff repair augmented with TFBC will have better biomechanical properties than that of DRSK repair with an acellular dermal graft (DG). Study Design: Controlled laboratory study. Methods: Fresh-frozen canine shoulders (n = 30) and knees (n = 10) were used. TFBCs were harvested from the patellar tendon–tibia complex and prepared for rotator cuff repair. The infraspinatus tendon was sharply detached from its bony attachment and randomly assigned to the (1) control group: DRSK repair alone, (2) TFBC group: DRSK repair with TFBC, and (3) DG group: DRSK repair with DG. All specimens were tested to failure, and videos were recorded. The footprint area, tendon thickness, load to create 3-mm gap formation, failure load, failure modes, and stiffness were recorded and compared. Data were recorded as mean ± SD. Results: The mean load to create a 3-mm gap in both the control group (206.8 ± 55.7 N) and TFBC group (208.9 ± 39.1 N) was significantly higher than that in the DG group (157.7 ± 52.3 N) ( P < .05 for all). The failure load of the control group (275.7 ± 75.0 N) and TFBC group (275.2 ± 52.5 N) was significantly higher compared with the DG group (201.5 ± 49.7 N) ( P < .05 for both comparisons). The stiffness of the control group (26.4 ± 4.7 N/mm) was significantly higher than of the TFBC group (20.4 ± 4.4 N/mm) and the DG group (21.1 ± 4.8 N/mm) ( P < .05 for both comparisons). Conclusion: TFBC augmentation showed superior biomechanical performance to DG augmentation in rotator cuff tears repaired using the DRSK technique, while there was no difference between the TFBC and control groups. Clinical Relevance: TFBC may help to reduce retear or gap formation after rotator cuff repair using the DRSK technique.

Age‐related cellular and microstructural changes in the rotator cuff enthesis

“…The etiology of enthesis degeneration represents an important gap in knowledge, particularly the understanding of cellular mechanisms that are required for robust healing and for the development of evidence‐based therapeutic strategies. Many biologic and engineering therapeutic strategies have been proposed for rotator cuff enthesis healing and regeneration; 46 however, animal model research has largely been focused on juvenile and young animals rather than mature or aged animals, which is a substantial weakness given that age‐associated changes are not present in these model systems. It is important to note that during aging systemic and local changes occur including increased accumulation of senescent cells within tissues and systemic increases in sterile inflammation, also termed inflammation, which compromise the ability of tissue to repair and regenerate.…”

“…[43][44][45] The etiology of enthesis degeneration represents an important gap in knowledge, particularly the understanding of cellular mechanisms that are required for robust healing and for the development of evidence-based therapeutic strategies. Many biologic and engineering therapeutic strategies have been proposed for rotator cuff enthesis healing and regeneration; 46 F I G U R E 6 Tenogenic potential of RCECs in different ages. RCECs from different-age groups were successfully differentiated into tenocytes lineage under inducement.…”

Editorial Commentary: Rotator Cuff Repair: Graft Augmentation Provides Promising Clinical Outcomes

“…Cadaveric biomechanical studies have shown greater load to failure and less repair displacement with graft augmentation. 6 Clinical studies have demonstrated the clinical benefit of graft augmentation as well. A recent randomized control trial by Avanzi et al 7 comparing single-row repairs with and without porcine dermal allograft augmentation in small-and medium-sized tears showed a clear benefit to graft augmentation.…”