Biomechanical evaluation of a novel suturing scheme for grafting load-bearing collagen scaffolds for rotator cuff repair

Abstract

Background Currently, there are no well-established suture protocols to attach fully load-bearing scaffolds which span tendon defects between bone and muscle for repair of critical sized tendon tears. Methods to attach load-bearing tissue repair scaffolds could enable functional repair of tendon injuries. Methods Sixteen rabbit shoulders were dissected (New Zealand white rabbits, 1 yr. old, female) to isolate the humeral-infraspinatus muscle complex. A unique suture technique was developed to allow for a 5 mm segmental defect in infraspinatus tendon to be replaced with a mechanically strong bioscaffold woven from pure collagen threads. The suturing pattern resulted in a fully load-bearing scaffold. The tensile stiffness and strength of scaffold repair was compared with intact infraspinatus and regular direct repair. Findings The failure load and displacement at failure of the scaffold repair group were 59.9 N (Standard Deviation, SD = 10.7) and 10.3 mm (SD = 2.9), respectively and matched those obtained by direct repair group which were 57.5 N (SD = 15.3) and 8.6 mm (SD = 1.5), (p > 0.05). Failure load, displacement at failure and stiffness of both of the repair groups were half of the intact infraspinatus shoulder group. Interpretation With the developed suture technique, scaffolds repair showed similar failure load, displacement at failure and stiffness to the direct repair. This novel suturing pattern and the mechanical robustness of the scaffold at time zero indicates that the proposed model is mechanically viable for future in vivo studies which has a higher potential to translate into clinical uses.

Biomechanic and histologic analysis of fibroblastic effects of tendon-to-bone healing by transforming growth factor β1 (TGF-β1) in rotator cuff tears

“…Results showed that BMP13 promoted tendon healing, because of its superior biological factor, and reduced the incidence of re-tearing. Hatta et al [25][26][27][28][29] demonstrated that BMP13 provided significantly better biomechanical performance when compared to traditional surgery in multiple double rows using the supraspinatus tendon in nine shoulders per group. In the current study, a greater degree of maximum load and stiffness at 16 weeks in the H-dose group suggested differences that were significantly higher than those of the other two groups.…”

Effects of PDGF-BB delivery from heparinized collagen sutures on the healing of lacerated chicken flexor tendon in vivo

“…Load-displacement curves were recorded using a closed loop controlled mechanical testing device (Test Resource 800LE3-2, Test Resources Inc., MN, USA) as described previously [25]. Briefly, samples were kept hydrated with wet gauze soaked in 1×PBS prior to testing.…”

Structural Design, Fabrication and Evaluation of Resorbable Fiber-Based Tissue Engineering Scaffolds

“…(A) Composite multilayer woven and electrospun scaffold [17]. (B) Pin woven scaffold made from novel electrochemically aligned collagen threads [19].…”