ABSTRACT
Objective To investigate the adaptation of metabolism of the arthrodial cartilage for limb lengthening. Methods Thirty New Zealand rabbits were divided into two groups: limb lengthening group (A) and delayed observation group (B). Each group was further divided into three sub groups ( n =10) according to the distraction ranges: 10%, 20%, and 40%. Upper tibia metaphysis lengthening was adopted at 1 mm/d rate of distraction and iconography changes of the knee joint were observed with X ray. The contents of glycosaminoglycan (GAG), hydroxylysine (HYL), and hydroxyproline (HYP) were determined by biochemical techniques. Results ① There was no obvious imaging change of knee articular cartilage at every time point in each group. ② The content of GAG was normal in group A 10 , and B 10 , and B 20 , but the content of galactosamine decreased obviously in group A 20 ( P 0.05). The content of GAG recovered obviously in group B 40 as compared with that in group A 40 . ③ The ratio of HYL to HYP was 0.18 and 0.17, respectively in group A 40 and group B 40 , but it was normal in other groups, nearly 0.24. Conclusion Metabolism of the arthrodial cartilage during low distraction range can adapt the stimulation of distraction, but great distraction range may result in transitory disorder in metabolic function of the arthrodial cartilage.