PROSTHETIC REPLACEMENT OF THE RABBIT MEDIAL MENISCUS

Implants of polyurethane-coated polyester (Dacron), polyurethane-coate d PTFE (Teflon), or uncoated PTFE were used to substitute the medial r abbit meniscus, and were observed over a 3-month period. Joint mechani cs were similar for sham-operation, meniscectomy, or substitution with a coated implant. Joints with an uncoated PTFE prosthesis tended to b e less compliant and to show greater load dissipation during relaxatio n. Cartilage indentation showed softening with all alternatives compar ed to sham-operation. Ingrowth into the prosthesis periphery was best with the PTFE implants. Both types of coated prosthesis retained their original shape, in contrast to the uncoated prostheses. To the naked eye the cartilage appeared unaffected only after sham-operation or imp lantation of a coated PTFE prosthesis. Osteophyte formation was common with all alternatives except sham-operation. We conclude that replace ment of the medial meniscus with coated prostheses, especially the PTF E, was better than meniscectomy or using the uncoated prosthesis. Howe ver, cartilage softening and osteophyte formation indicate that joint mechanics were not restored to normal. (C) 1993 John Wiley & Sons, Inc .