Meniscal regeneration and its effects on articular cartilage in rabbit knees

The incidence and size of meniscal regeneration after medial meniscectomy on the right knee and lateral meniscectomy on the left knee of 44 rabbits was observed and correlated with development of degenerative arthritis. Complete meniscal regeneration was found in 23% of medial meniscectomy knees, partial regeneration in 68%, and no regeneration in 9%. Among 44 lateral meniscectomies, only 5% had complete meniscal regeneration, and 68% had no meniscal regeneration. The remaining 27% of knees had partial regeneration. Degenerative changes of articular cartilage in the tibiofemoral joints of all knees were inversely correlated with the size of the regenerated meniscus. These observations suggest that poor results following lateral meniscectomy may be due to a lower level of meniscal regeneration and relatively poor morphological regeneration of the lateral meniscus compared to the medial meniscus.