早期制动对兔髌骨-髌腱连接点断裂修复的生物力学影响

摘要

目的:探讨早期制动对兔髌骨-髌腱连接点(BTJ)断裂修复的生物力学影响.方法:36只成年新西兰大白兔随机分为实验组(18只)和对照组(18只),建立兔髌BTJ损伤修复模型后实验组予以石膏固定3周后去除,对照组不予固定,分别在术后2、4、8周取髌骨-髌腱复合体标本比较横截面积、拉断负荷以及极限拉应力的差异.结果:术后2、4、8周实验组横截面积分别为:(22.38±4.25)mm2、(17.13±3.68)mm2、(14.65±3.27)mm2,对照组分别为:(24.45±4.47)mm2、(22.74±4.18)mm2、(16.78 ± 4.03)mm2;实验组拉断负荷分别为:(35.92±8.68)N、(81.05±9.16)N、(172.58±15.66)N,对照组分别为:(33.64±7.89)N、(56.69±8.56)N、(136.09±15.20)N;实验组极限拉应力为:(1.76±0.64)Mpa、(5.23±0.93)Mpa、(14.26±2.02)Mpa,对照组极限拉应力:(1.68±0.67)Mpa、(3.72±1.07)Mpa、(9.13±1.66)Mpa.术后2周横截面积、拉断负荷以及极限拉应力无显著性差异(P＞0.05),术后4周、8周实验组和对照组横截面积、对照组拉断负荷及极限拉应力比较均有显著性差异(P＜0.05).结论:术后早期制动促进韧带塑型,提高BTJ拉断负荷以及极限拉应力,可加快兔髌BTJ的损伤修复,改善BTJ的生物力学性能,促进其愈合.%Objective:To investigate biomechanical influence of early immobilization on rupture and repair of patellar bone-tendon junction (BTJ) of rabbits.rnMethod: Thirty-six adult New Zealand rabbits (18 weeks old) were established the BTJ ruputure and repair model, and randomly divided into two groups, the immobilization group (18 rabbits,immobilized for 3 weeks) and the control group (18 rabbits, without immobilization). In both groups the samples of patellar-tendon complex were sectioned 2 weeks (6 rabbits), 4 weeks (6 rabbits) and 8 weeks (6 rabbits) after operation respectively. All the samples were used for biomechanical tests, including cross-section area, breaking load and ultimate tensile stress. Result: The cross-section areas of experimental group, at 2, 4, 8 weeks after operation were (22.38 ± 4.25)mm , (17.13 ±3.68)mm2 and (14.65 ± 3.27)mm2 respectively; that of the control group were (24.45 ± 4.47)mm2,(22.74 ± 4.18) mm2 and (16.78 ± 4.03)mm2 respectively. Breaking load of experimental group were (35.92 ± 8.68)N, (81.05 ± 9.16)N and (172.58 ± 15.66)N respectively; that of control group were (33.64 ± 7.89)N, (56.69 ± 8.56)Nand (136.09 ± 15.20) N respectively. Ultimate tensile stress of experimental group were (1.76 ± 0.64)Mpa, (5.23 ± 0.93)Mpa and (14.26 ± 2.02)Mpa respectively; that of control group were (1.68 ± 0.67)Mpa, (3.72 ± 1.07)Mpa and (9.13 ± 1.66)Mpa respectively. Comparing the cross-section area, breaking load and ultimate tensile stress of two groups, there was no significant difference (P>0.05) at 2 weeks after operation and existed significant difference(P < 0.05) at 4, 8 weeks after operation.Conclusion: Early immobilization on rupture of patellar BTJ can accelerate repairing the injury, improved the bio-mechanical characteristics and facilitated the BTJ healing in rabbits.