Perichondrial Arthroplasty in a Canine Elbow Model

The purpose of this study was to use a canine model to compare the ability of vascularized and nonvascularized perichondrial grafts to resurface an experimental joint defect. In five adult mongrel dogs, a 3 x 2 cm segment of perichondrium, subtended by the intercostal-internal mammary vessels, was harvested and transplanted to a surgically created defect on the ulnar condyle of the humerus. A similar defect in the opposite elbow was repaired with a 3 x 2 cm standard perichondrial graft. Five untreated dogs acted as normal controls. The dogs were allowed to mobilize freely for a period of 6 months. At that time, angiography demonstrated that all microvascular anastomoses were patent. There was no statistical difference in the range of motion of the two elbows, in the radiographic appearance, or in bone density of the two groups of joints. Histologic assessment demonstrated that the vascularized perichondrium formed an articular cartilage with an average thickness of 21.8 microns as compared with 38.5 microns for the nonvascularized perichondrium (p < 0.05). The cartilage in both grafts was morphologically hyaline in type. There were degenerative changes in the grafts with partial separation of the graft from the underlying bone and formation of surface clefts or pits, villous projections, and synovial proliferation. Degenerative changes also were observed on the articular surface opposite the grafted humeral condyle. In two animals the grafts displaced from the recipient condyle, which instead became resurfaced by greater amounts of hyaline-type cartilage with lesser degrees of degeneration and subarticular fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)