Convincing evidence shows that intra-synovial tendon grafts are superior to extra-synovial grafts in terms of healing and functional outcome. Yet, due to the added procedural difficulty and limited expendable donor sites, the vast majority of patients undergoing flexor tendon grafting receive extra-synovial grafts (palmaris or plantaris). The purpose of this study was to test the biomechanical properties of a tissue-engineered rabbit flexor tendon construct that was acellularized and reseeded with intra-synovial tenocytes. Tensile testing was performed to compare the ultimate tensile stress and elastic modulus of the tissue-engineered prototype to control flexor tendons.
The results revealed that the treatment protocol was capable of successfully acellularizing the flexor tendons and reseeding them with tenocytes. Tensile testing showed that acellularized tendon had the same ultimate stress and elastic modulus as normal tendons. However, the reseeded tendons had the same elastic modulus as normal tendons, but showed decrease in ultimate stress as compared with normal tendons. The authors conclude that acellularized flexor tendons are a potential high-strength scaffold for flexor tendon tissue engineering.
This article presents important preliminary data on a promising tissue-engineered flexor tendon model that may have future clinical utility. The authors were able to nicely demonstrate that tendons can be made acellular without significant alteration of mechanical properties. They further show that the acellularized tendons can be reseeded with tenocytes obtained from other intra-synovial tendon specimen with only a modest amount of tensile weakening. Future investigation needs to evaluate the antigenicity of this model and in-vivo adhesion formation.