Intra-articular implant of filamentous carbon fibre in the experimental animal.

The effects of filling drilled holes and articular cartilage grooves in rabbit femora with 9 micrometer diameter filamentous carbon fibre in vivo were studied. The animals were killed at four weeks and five months and the medial and lateral femoral condyles removed and studied morphologically by gross and scanning electron microscopic examination, and histologically using hematoxylin and eosin, van Gieson, toluidine blue and safranin O staining techniques. Fibrous tissue appeared to surround the carbon fibre bundle and emerge at the surface in large organised bundles, overflowing to cover the surface adjacent to the hole defects. Fibrous tissue surrounds the carbon fibre bundle, and forms a new surface over grooves made in the articular cartilage of rabbits that were kept alive for five months, the tissue within the control grooves filled with disorganised fibrous tissue. There was very little foreign body reaction and the fibrous tissue appeared to grow parallel and surround the carbon fibre bundle.