Histologic pattern of biomechanic properties of the carbon fiber-augmented ligament tendon. A laboratory and clinical study.

Implantation of carbon fiber tow (CFT) for ligament and tendon augmentation was investigated in ten dogs and 45 patients. CFT produced a new structure with a remarkably consistent structural pattern. The basic pattern of the CFT-augmented unit consisted of a core of carbon fiber surround by concentric layers of fibroblasts and collagen fibers. This unit structure was developed from continuous irritation of physical structure of the carbon fiber. In dogs, ultimate tensile strength of the augmented tendon one year after surgery averaged 88% of natural tendon. Digestion of the connective tissue component of the CFT unit exposed the original carbon fiber tow. The connective tissue-free CFT maintained its original tensile strength. The continuous production of collagenous tissue surrounding carbon fibers produced a ligamentous structure that was physiologically compatible and biomechanically sufficient.