[Chondrogenic potential of a free autogenous periosteal graft for biological resurfacing over a half-thickness defect in a joint surface: an experimental study].

We report the results of chondrogenesis from a free autograft of periosteum taken from the medial tibial condyle transplanted over a partial-thickness defect created on the medial femoral articular surface in immature white rabbit. A total of 69 rabbits were randomly divided into four groups as follows, Group I received the free autograft and were allowed intermittent activity in a cage. Group II also received a free autograft but were allowed only continuous passive motion in a CPM apparatus for 8 hours a day for the first two weeks after the operation. Group III received a freeze-dried periosteal graft and were allowed intermittent activity in a cage. And Group IV as controls received no graft over the created defect and were allowed intermittent activity in a cage. In specimens from Group I and from Group II at 3 weeks postoperatively, hypertrophic cells were recognized. In both groups at 4 weeks postoperatively, the autograft had sealed the defect with interposition of fiber bundles. At 8 weeks postoperatively, the union of both matrices was clearly demonstrated. The chondrocyte arrangement and matrix bonding was observed to be better in Group II than in Group I. In specimens from Group III at 8 weeks postoperatively, the freeze-dried periosteum had deteriorated without sealing the defect. In Group IV at 8 weeks postoperatively, the surface of the shaved cartilage was irregular and similar to that in arthrosis. These findings indicated that a periosteal free autograft produced bonding between the matrix of the graft and the matrix of the host cartilage, and was therefore effective for chondrogenesis to seal over a joint defect.