Reconstruction of patellar articular cartilage with free autologous perichondrial grafts. An experimental study in dogs.

The cartilaginous potential of the perichondrium has earlier been utilized to reconstruct articular cartilage in unloaded joints in adult rabbits. The present work in adult dogs has been performed to find out if the perichondrium can be used for the same purpose in joints subjected to pressure. In 13 knee joints the articular cartilage of the patella was excised completely and the resected surface was covered with an autologous perichondrial graft taken from the rib cartilage. After 3 weeks of immobilization the dogs were allowed to run freely until sacrifice 2 to 17 months later. In all 13 cases regeneration of cartilage took place. Within 8 months the regenerated cartilage showed no or only very slight degenerative signs but from 12 months and later such changes were common. In control cases where the resected surface was left without any graft no cartilage at all was found. Conclusively cartilage formation from grafted rib perichondrium is achieved in the knee joints of adult dogs, but it does not resist considerable pressure forces.