低强度不同频率全身震动治疗对兔膝骨关节炎的影响

Effects of Low-magnitude Whole Body Vibration (WBV) on Knee Osteoarthritis in Rabbits

目的研究不同频率低强度全身震动治疗(WBV)对于兔膝骨关节炎软骨下骨微结构、软骨降解、骨/软骨转换以及关节功能的影响。方法成年新西兰兔96只,随机分为膝关节前交叉韧带切断术组(ACLT组,16只)和WBV+ACLT组(80只)。各组行左侧ACLT,制备膝骨关节炎模型。术后2个月,ACLT组不行WBV治疗,WBV+ACLT组分别以频率5Hz、10Hz、20Hz、30 Hz、40 Hz进行WBV治疗(每亚组16只),震动幅度2~4mm,40min/d,5d/周,持续治疗8周。治疗8周后采用负重不对称法检测关节疼痛度;尾静脉血液及尿液采集检测骨/软管转换标记物血清软骨寡聚基质蛋白(COMP),骨转换标记物1型/2型胶原羧基末端肽(CTX-Ⅰ、CTX-Ⅱ),运用Micro-CT仪扫描各组模型左侧膝关节,并分析软骨体积和骨微结构;关节软骨采用大体形态学和组织学评分分析。结果治疗8周,与ACLT组相比,10Hz(P<0.05)和20Hz(P<0.01)亚组疼痛改善明显,而40Hz(P<0.05)亚组则疼痛加重;大体评分和组织学评分,仅40 Hz亚组内侧髁与ACLT组相比评分增加(P<0.05),病变更重;Micro-CT结果显示,关节软骨体积随着频率的改变呈现先增加后减少的变化趋势,以20 Hz亚组与ACLT组相比增加最为明显(P<0.05);骨小梁厚度、骨小梁数量和骨体积分数随频率的增加而增加(P<0.05);CTX-Ⅰ随频率上升表达下降(P<0.05),而COMP和CTX-Ⅱ的表达随频率增加先降低后升高,以20 Hz亚组最低(P<0.05)。结论较低频率(20 Hz)WBV可有效改善关节功能和软骨下骨微结构,增加骨转换,延缓软骨降解,为较优治疗参数。

Objective To determine the effects of low-magnitude whole body vibration （WBV） on the structure and function of subehondral trabecular bones, cartilage degradation, bone/cartilage turnover, and osteoarthritis （OA）joint function. Methods Knee osteoarthritis model was established in 96 rabbits through left anterior cruciate ligament transaction （ACLT）. The rabbits were randomly divided into six groups： ACLT control group, WBV-q-ACLT group （five subgroups, each comprising 16 rabbits receiving 5 Hz, 10 Hz, 20 Hz, 30 Hz and 40 Hz WBV, respectively, with 2-4 mm amplitude for 40 min/d and 5 d/week over a period of 8 weeks）. Joint function was tested via weight-bearing asymmetry. The mieroarchitecture of subchondral trabecular bones was examined using vivo micro-computed tomography （micro-CT）. Cartilage samples from knee joints were taken for gross morphology and histology examinations. Serum samples were taken to detect cartilage oligomeric matrix protein （COMP）, C-terminal telopeptide of type I collagen （CTX）- Iand urine CTX- IIResults Knee joint pain decreased with 10 Hz （P〈0.05） and 20 Hz WBV treatment （P〈0.05）, but increased with 40 Hz treatment （P〈 0.05）. The micro-CT results showed that articular cartilage increased first, peaked at 20 Hz, and then decreased （P〈0.05）. With increased frequency of WBV, the trabecular number, subchondral bone thickness and bone volume fraction increased, serum CTX-I decreased, COMP and CTX-ll increased, especially at 20 Hz （P〈 0. 05）. Conclusion Lower frequency （20 Hz） WBV can improve bone microstructure, increase bone turnover, delay cartilage degeneration and improve limb function of rabbits with OA.