The structure and innervation of cat knee menisci, and their relation to a "sensory hypothesis" of meniscal function

Previous work on dog knee menisci demonstrated structural differences between the meniscal horns and the meniscal bodies (O'Connor, '76). Of particular interest was the observation that the meniscal horns possessed an abundant blood and nerve supply, while the meniscal bodies did not. The presence of nerves in the meniscal horns prompted the speculation that menisci might perform a sensory function. The present study was undertaken in order to establish whether or not similar regional differences existed in cat knee menisci, structures previously believed to lack a corpuscular mechanoreceptor system (Freeman and Wyke, '67). Differences between the meniscal horns and meniscal bodies similar to those reported in the dog were found to characterize cat knee menisci. In particular, the meniscal horns possessed a rich neurovascular supply, while the meniscal bodies did not. Most important, at least two morphologically different mechano-receptors were identified in the meniscal horns, but none were identified in the meniscal bodies.