实验性胫骨延长对膝关节功能变化的影响

目的:探讨肢体缓慢牵伸延长过程中关节功能变化规律。方法:30只健康成年新西兰兔随机分为延长组(A组)及停止延长3个月组(B组),各组按延长幅度不同又分为延长10％、20％及40％3个亚组。采用胫骨上干骺端1mm/d速度缓慢牵伸延长术。X线确定延长幅度及膝关节影像学变化:确定延长终止及取材时膝关节屈伸范围。结果:(1)各组不同时相点膝关节软骨未见明显影像学异常;(2)A组中延长20％时出现显著性膝关节屈伸功能障碍(P<0.05),延长40％时仅为正常的44.7％左右(P<0.01);B组关节功能均有显著性改善,其中延长20％组已恢复至延长前水平,而延长40％组也较延长终止明显改善,但仍低于延长前正常水平,为正常水平的88.5％左右(P<0.05)。结论:肢体延长过程中可能出现暂时性关节功能障碍,并主要发生在大幅度延长时。虽在延长停止后可逐渐恢复,但仍需积极防治。

Effect of Limb Lengthening on Motor Function of Knee

Objective: To investigate the changes of motor function of knee joint during tibia lengthening in rabbits. Method: Thirty-five New Zealand rabbits were divided randomly into two groups, limb lengthening group (group A) and delay observation group (group B). Every group was further divided into three sub-groups according to distraction range: 10% ,20% and 40% . Upper-tibia metaphysis distraction was adopted at Imm/d rate of distraction and iconography changes of knee joint were observed with X-ray. The motive range of knee was investigated at the end of distraction and three months later. Results: 1) There was not obvious radiographical change of knee at every time phase in each group. 2) The motive range of knee before distraction was 95 - 97 percent of pre-operation. In group A, it was normal for the motive range of knee when 10 percent distraction range achieved, but it was observably decreased both at 20 and 40 percent distraction range, it was only 44.7 percent of normal in the 40 percent group. After three months, it was recovered signally in group B compared with group A. In all of them, the motive range of knee had recovered to the level of pre-distraction in 20 percent distraction group. The same was happened that compared with the level of end-distraction in 40 percent distraction group, although it was still lower than that of normal. Conclusion: It is probably happened the provisional disorder of motive function of knee joint during limb lengthening, especially the great range of distraction has been gotten.