Morphologic changes of arthrodial cartilage of tibial platuea during tibiae lengthening / 中华骨科杂志

ABSTRACT

Objective To investigate the adaptation of metabolism of arthrodial cartilage for limb lengthening. Methods Thirty New Zealand rabbits were randomized into two groups, limb lengthening group (group A) and delay observation group (group B). Every group was subdivided into three sub-groups according to distraction degree 10%, 20% and 40%. Upper-tibia metaphysis lengthening was adopted at 1 mm/d rate of distraction and iconography changes of knee joint were observed with X-ray, the morphologic changes of chondrocyte and cartilago articularis on tibial flat were observed with light and electric microscope. The changes of cartilage surface were observed with scanning microscope. Results 1) There was no obvious iconography change of knee at every time phase in each group. 2) Pale of cartilage on tibial flat were just noted in group A40 and B40. 3) The arrangement of chondrocyte was disorder in A40, some degenerating and generating chondrocytes were found in the same group. The number of chondrocytes increased, and the volume was expanded in group B20 or B40, the degenerating chondrocytes were not found in the same group. 4) Low-grade expansion of endoplasmic reticulum and swelling of chondrosome were found in part of chondrocyte in group B40 contrasting with the other groups. The numbers of endoplasmic reticulum and matrix alveolus increased in chondrocyte. The same changes were observed in group A. 5)The cartilage surface lost its smoothness during distraction, and this kind of changes were more severe when distraction increased. Conclusion The articular cartilage showed certain adaption to stimulation of distraction during low degree distractions. To greater distraction degrees some abnormality in metabolism of arthrodial cartilage may occure.