A PRELIMINARY STUDY OF STRESS FRACTURE IN RABBIT TIBIAS
- VernacularTitle:兔胫骨应力性骨折的模拟实验研究
- Author:
Guoping LI
;
Shudong ZHANG
;
Gang CHEN
- Publication Type:Journal Article
- From:Chinese Journal of Sports Medicine
1982;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
The objective of this experiment was to study the sequential pathologic changes in the remodeling of the internal structure of the tibia, caused by controlled excessive jumping and running. Eighteen rabbits were exercised separately in two electrical cages with high voltage and low current. They were forced to jump and run in a manner which simulated athletic activity. Two additional rabbits served as controls. The rabbits were sacrificed periodically to obtain the required specimens. Radiographic and histologic methods were applied to observe the development of the pathologic changes of the tibia throughout the sixty-day experimental period.Vascular changes and circulatory disturbances within the cortical bone occurred before osteoclastic resorption. Degeneration and necrosis of osteocytes due to circulatory disturbances also occurred. Periosteal new bone formation found on and after 14 days of the experiment was a compensatory reaction to support the tibia which was weakened by the accelerated ostoclastic resorption. A Small crack appeared at the cement line and propagated through the neighboring cement line of the Haversian systems. After 21 days, incomplete fracture of the tibial cortex was found in two rabbits. Complete fracture on one side of the cortex was seen in 1 animal on the 50th day of the experiment. In addition, degeneration and necrosis of the surrounding muscles were also observed microscopically. In this study, however, most of the tibias did not have visible fracture lines after a period of strenuous exercise. This result suggests that most tibias can adapt to changes under stress through proper internal remodeling, so that a complete fracture rarely occurs.
