全身振动治疗对兔膝骨关节炎早期软骨下骨结构与功能重塑的影响

Effects of Whole Body Vibration on Structural and Functional Remodeling of Subchondral Bones in Rabbits with Early Osteoarthritis

目的研究全身振动治疗（WBVT）对兔膝骨关节炎软骨下骨结构与功能重塑的影响。方法新西兰兔24只，随机分为膝关节前交叉韧带切断术（ACLT组）和WBVT＋ACLT组，每组12只。两组行左侧ACLT，制备膝骨关节炎模型。术后2个月wBVT＋ACLT组实施WBVT。振动治疗参数为：频率40Hz，振动幅度2～4mm，40min／d，5d／周，持续治疗4周。治疗完成后，取两组动物左侧膝股骨和胫骨置于Micro—CT系统进行扫描，应用Micview V2．1．2三维重建处理软件和ABA专用骨骼分析软件对股骨髁和胫骨平台骨小梁体积分数（BVF）、骨小梁厚度（Tb．Th）、骨小梁分离度（Tb．Sp）、骨小梁数量（Tb．N）、体积骨密度（vBMD）和组织骨密度（tBMD）进行检测。应用Geomagic Studio 11．0软件换算股骨髁和胫骨平台弹性模量（EM）、反应力（RF）和平均Von Miss应力（VMF）。结果显微CT成像结果发现：ACLT组软骨下骨骨小梁出现稀疏表现并呈现断裂现象，部分骨小梁排列紊乱，结构扭曲。关节边缘处见不同程度的椭圆形或圆形骨赘形成。WBVT＋ACLT组软骨下骨骨小梁虽然也出现稀疏断裂的现象，但直观上较ACI．T组骨小梁排列较为整齐有序，少见结构性扭曲。WBVT＋ACLT组与ACLT组相比较，BVF、Tb．N、Tb．Th，股骨的EM、RF和VMF升高（P〈0．05）；Tb．Sp减少（P〈0．05）。骨密度（vBMD和tBMD）增加（P〈0．05）。结论WBVT可有效改善兔膝骨关节炎早期阶段软骨下骨微结构和力学性能，起到保护进展性骨关节炎软骨下骨微损伤和力学性能降低的作用。

Objective To investigate the effects of whole body vibration therapy （WBVT） on structural and functional remodeling of subchondral bone in rabbits with early Osteoarthritis （OA）. Methods Twenty-four adult rabbits received anterior cruciate ligament transaction （ACLT） to establish knee osteoarthritis model. The rabbits were randomly divided into two groups： ACLT group and WBVT ＋ ACLT group. The rabbits in the WBVT＋ ACLT group received whole body vibration treatment （Frequency： 40 Hz; Amplitude ： 2-4 mm ;40 rain/d, 5 d/week, 4 weeks） two months after surgery. After interventions, the left femur and tibia of all rabbits were placed in a Micro-CT scanning system. The bone volume fraction （BVF）, trabecular thickness （Tb. Th）, trabecular spacing （Tb. Sp）, trabecular number （Tb. N）, volumetric BMD （vBMD） , and tissue BMD （tBMD） of the bones of femoral condyle and tibia were analysed using three-dimensional reconstruction Micview V2.1.2 and ABA analysis software. Geomagic Studio 11.0 software were used to calculate modulus （EM）, reaction force （RF） and average Von Miss stress （VMF）. Results Higher levels of BVF, Tb. N, Tb. Th, EM, RF, VMF, vBMD and tBMD and lower levels of Tb. Sp were found in distal femora and tibia of the rabbits in the WBVT＋ACLT group compared with the controls （P〈0.05）. Conclusion WBVT can effectively improve bone microstructure and mechanical properties of rabbits with early knee osteoarthritis.