COMPARISON OF VARIOUS INTERPOSITIONAL MATERIALS IN THE PREVENTION OF TRANSPHYSEAL BONE BRIDGE FORMATION

Various interpositional materials, except muscle, have been used to pr event transphyseal bone bridge formation after resection of the damage d physeal plate. In this animal model, muscle was used as an interposi tional material, and its effectiveness was compared with that of 3 kno wn materials (fat, physeal allograft, and iliac apophyseal autograft). Five experiments were done on the distal femoral physis of 40 skeleta lly immature 3-month-old New Zealand white rabbits. The rabbits mere d ivided into 5 groups, each containing 8 rabbits. A standard defect was created in the lateral distal physis of the left femur in all the rab bits. In Group A, there was no interpositional material. Vastus latera lis muscle, groin fat, physeal allograft, and iliac apophyseal autogra ft were inserted into the femoral defect in Groups B, C, D, and E, res pectively. The right femur served as a sham control for the animals. T he animals were sacrificed at 12 weeks after surgery. The results of l imb length discrepancy and angular deformity of the groups with interp ositional material were compared with those of Group A (experimental c ontrol). Muscle, fat, and iliac apophyseal autografts had less severe limb length discrepancy and angular deformity. These differences were statistically significant, whereas the differences between allograft a nd experimental control were statistically insignificant.