The effects of fat interposition for central-physeal defects. A histologic study in rabbits

The effects of autogeneic fat interposition in a central cylindrical physeal defect were observed in rabbits. A 3.6-mm longitudinal drill hole was made across the physis of the distal femur, bilaterally, in four- to six-week-old New Zealand rabbits. One side was filled with an autogeneic fat graft and the contralateral defect was left as a control. The rabbits were killed at intervals during the remaining growth period, and the defects were examined histologically. Although fat grafts reduced the rate of osseous bridging across the physis and allowed more longitudinal growth than controls, transverse regeneration of the physis did not occur in the eight-week period preceding closure. The lack of physeal regeneration across the gap may reflect an important difference between central and peripheral defects.