The aim of the experiment was to evaluate the possibility of preventing bone bridge formation in damaged distal femoral physis using implantation of autogenous chondrocyte graft. Ten pigs were used in the study. In each pig, a sample of cartilage of 3 × 3 mm in diameter was taken from non-weight-bearing surface of the lateral femoral condyle and used to culture chondrocytes for the preparation of the autogenous chondrocyte graft.Fourteen days later, a canal of 4 mm diameter was drilled through the distal femoral physis in the area of the lateral condyle. This canal was then filled with the autogenous chondrocyte graft. The same defect, left unfilled, was created in the physis of the medial condyle. One animal succumbed during the transplantation of the chondrocyte graft due to complications of anaesthesia.Remaining 9 animals were euthanised and examined histologically with respect to the healing of the transplant in the area of the growth plate. In all 9 cases the graft was healed in the distal femoral physis. Bone bridges were formed in canals unfilled with the autogenous chondrocyte graft.We conclude that transplantation of the autogenous chondrocyte graft into iatrogenically damaged physis in pigs can prevent bone bridge formation and growth arrest. This finding may have clinical implications in potential transplantation of chondrocyte autografts in children.
Growth plate, injury, bone bridge, pigGrowth plate fractures in children, in particular those ones of types III to V according to the classification by Salter-Harris (1963), belong to injuries of poor prognosis. Damage to the regular chondrogenesis in the physis can result in altered growth of the bone affected due to the formation of a bone bridge. In dependence on its location we recognise either a peripheral bone bridge resulting in angular deformities of the bone affected, a central bone bridge shortening the bone without its angular deformity or a combined kind of a bridge causing both angular deformities and shortening of the bone (Rockwood et al. 1984). Combined bone bridges are least favourable for the patient (Rockwood et al. 1984). Iatrogenic damage to the physis during surgical repositioning of a physeal fracture can lead to the formation of osteonecrotic bone bridges and then can form a bone bridge in the fissure after incomplete repositioning of fragments (von Laer 1984). Clinical consequences of physeal bone bridging are often very serious (Bak and Boeckstyns 1997) and their therapy includes complex corrective surgeries (Hove and Engesaeter 1997) or complicated resections of bone bridges (Langenskiold 1981).Trauma to the distal femoral physis is a typical example of injury to the growth plate in children. This injury, common in preadolescents and adolescents, is not so frequent but can