Augmentation by autogenous tissue in the repair of acute anterior cruciate ligament injury has been found to be of benefit in providing a scaffold for the disrupted tissue and a stent to protect the repaired tissue, thereby ultimately increasing the strength of the repair. In both the acute setting and when autogenous tissue is used to reconstruct a chronic anterior cruciate-deficient knee, the substitute tissues require protection while revascularization and recollagenization take place. Potential solutions to these problems are sought in a ligament prosthesis, such as carbon fibers, that would be capable of providing both a stent for protection and an inducement for collagen ingrowth. Intra-articular reconstruction of the anterior cruciate ligament with autogenous tissue augmented by PLA-coated carbon fibers was performed in one group of ten patients. A second group of matched cases was similarly treated but without augmentation for controls. The results were analyzed at one year postoperation on both the 100-point protocol rating system and the authors' 200-point knee rating system. On the 100-point scale, the study group improved by 14.8% of the preoperative rating, while the comparison group improved by 23.3%. On the 200-point system, the study group improved by 21.9%, the comparison group by 22.6%. There was no demonstrable benefit in the use of carbon fiber to augment intra-articular, autogenous tissue anterior cruciate ligament reconstructions.