(The) effects of fractures on the longitudinal bony growth of a growing long bone in rabbits
Since Duhamel(1739), numerous experimental studies on the longitudinal growth of growing long bone have been reported.
In Hales'(1747) experience, growing long bone showed overgrowth after drilling in the tibia of chickens.
David(1924) observed the fact that various degrees of shortening disappeared wihin 15 months after fracture of the femur in children and he concluded that fractures in children should be treated with the caution that the growing long bone
has a tendency to increase in length after injury.
Bisgard(1936) concluded that shortening from overriding of fragments in fractured extremities of children will frequently, but not invariablly, become partially or totally eliminated by the acceleration of growth which incidentally results from the inflammatory process, incited by trauma and fracture repair.
Hass(1926) reported that interstitial proliferation of osseous tissue plays no part in the elongation of a growing bone, either in the mature bone or the young osteoid tissue bordering on the epiphyseal cartilage plate, and length growth of bone is entirely dependant on the purposeful multiplication of cartilage cells of
the epiphyseal cartilage plate.
Ham(1952) reported that the growth of long bone depends upon the interstitial growth of cartilage.
This study was initiated to investigate the effects of fractures in the longitudinal bone growth of growing bone. Artificial fractures were made at two different sites in the diaphysis of the tibia in young rabbits. The operation for
artificial fracture was performed under general anesthesia with ether. The type of fracture was and incomplete one, leaving a part of the posterior cortex of the tibia, in order to prevent the displacement of fracturcd fragments. In all of the cases, no cast immobilizatio was applied.
After the fractures, follow up observations were made weekly till the 4th week, and thereafter at two week intervals, with roentgenographic, lethal measurement and histological examination.
The results were as follows;
1) Longitudinal bone growth was increased from fracture of the diaphysis of growing long bone.
2) Compared with the control limb, tendency to overgrowth of growing bone was noted from the first week after the operation.
3) In follow up measurements, no growth inhibition was observed till the 10th week after the operation, but, there after, a tendency to reduce the proliferation of cartilage cells was noted.
4) In cases of fracture of the mid 1/3, the growing activity in the epiphyseal plate was increased mere than from proximal 1/3 fractures.
5) The bony growth, accelerated by fractures in diaphysis of growing long bone without displacement was transient, and the prolonged overgrowth was compensated by the reduction of growing activity and premature closure of the epiphysis.