DURABILITY OF ARTIFICIAL IMPLANTS FOR REPAIR OF OSTEOCHONDRAL DEFECTSOF THE MEDIAL FEMORAL CONDYLE IN RABBITS

Full-thickness osteochondral defects in the femoral condyles of 25 rab bits were repaired using artificial implants made of Teflon(R) or Dacr on(R). The 6 and 12 month results were compared with ungrafted defects (natural repair) and periosteal grafting. Throughout the observation period, all repair sites were three-fold more compliant than normal ca rtilage (P < 0.01). The adjacent cartilage was unaffected. Splits betw een the repair sites and the adjacent cartilage were common. At 6 mont hs, the Dacron repairs had higher scores than natural repair (P < 0.05 ). Between 6 and 12 months, no significant change in appearance was no ted for the artificial repairs. At 1 yr, the scores for natural and Da cron repairs were similarly high, but natural repair had more surface fibrillation (P < 0.05). Periosteal grafting had a lower score than Da cron repair (P < 0.01). Synovitis and artificial debris tended to decr ease with time (n.s., P < 0.06). In the present model, Dacron repair o f small cartilage defects at 1 yr showed better neocartilage quality t han periosteal grafting. Dacron had earlier neocartilage formation tha n unrepaired defects, and showed no late deterioration, but normal car tilage mechanics and morphology were not attained.