A study of experimental trauma and attempts to stimulate growth of the lower femoral epiphysis in rabbits. III.

This is the third report of a continuous of experiments performed On the distal femoral epiphysis of baby rabbits. In the second report by Key and Ford it was shown that small Vitallium nails driven through the epiphysis and across the epiphyseal plate from the intercondylar notch of the femur in a small group of five rabbits did not cause deformity or interference with growth. Of these five rabbits, two showed one millimeter of overgrowth of the nailed femur as compared with the control side ; two rabbits showed one millimeter less growth; and in one rabbit the experimental and control femora were equal in length. It was apparent that no significant alteration of growth of the femora was produced by this procedure. Since Vitallium nails were used in that experiment we wondered if stimulation of growth might be obtained if similar experiments were performed using irritating metals. Clinically, stimulation of linear growth in long bones of children or adolescents may be seen as the result of fracture, osteomyelitis, alteration in circulation, joint infection, tumor, or congenital anomaly. Experimentally and clinically, bone growth has been stimulated by placing foreign materials in the metaphyseal area near the epiphyseal cartilage. Unfortunately, this method is not dependable, accurate, or consistent. As bone grows, the epiphyseal cartilage moves away from its stimulating influence. For that reason we believed that placing nails across the epiphysis would allow any stimulating influence to remain in continuous contact with the epiphyseal cartilage. Bohlman, in 1929, reported attempts to stimulate longitudinal growth in guinea pigs. Among other substances placed in drill holes in the tibia, he used iron, iron oxide, copper, copper oxide, lead, and lead carbonate. No stimulation, only slight shortening, resulted. \Vu and 1\Iiltner found no stimulation of growth when lead shot was placed in drill holes in the tibia in rabbits. Chapchal and Zeldenrust inserted steel, copper, iron, and zinc near the epiphyseal cartilage in rabbits and obtained alteration in growth of from 3.5 millimeters of shortening to 8.3 millimeters of overgrowth. They worked with both the femur and the tibia. Herndon and Spencer placed a copper plug in a drill hole in the distal metaphysis of the femur in ten rabbits. No appreciable linear acceleration of growth resulted. In a large series of dogs, Wilson ‘#{176}“ obtained a slight increase in leg length in young puppies by inserting in the bone combinations of copper, iron, aluminum, steel, brass, zinc, nickel, silver, and constantan. The most stimulation was obtamed with copper and constantan, using a plate made of the two metals, fastened to the bone with screws. He also reported some similar work in children in which a maximum of one-half inch of stimulation in leg length was obtained in one case. Pease, in 1952, gave a preliminary report of seven children in whom he had