Absorbable polymer-filamentous carbon composites--a new class of tissue scaffolding materials

The utility of filamentous carbon in tendon and ligament repair is limited by its premature mechanical degradation. When filamentous carbon is coated with an absorbable polymer, polylactic acid (PLA), a composite material results which serves as a tissue scaffold, maintaining its integrity long enough for new tissue to grow in and around it before it gradually degrades. Biocompatibility studies showed excellent tissue response to the PLA-carbon composite. Dog patellar tendons and medial collateral ligaments and rabbit Achilles tendons fashioned from the composite were then implanted. The implants allowed almost immediate resumption of activity and encouraged the growth of new structures histologically and mechanically similar to the natural structures. Its high initial strength, rapid ingrowth and benign tissue reaction suggest that this new composite material may be useful in the treatment of tendon and ligament injuries in humans. Consequently, the material was entered into limited clinical trials. To date, thirty patients have had implant surgery for the repair of extensor mechanisms, knee ligaments, Achilles tendons, and rotator cuffs. At this writing, seven month follow-up is available. Early results are encouraging.