半月板部分切除后胫股关节接触面积及生物力学变化

Tibiofemoral joint contact area and biomechanical changes after partial meniscectomy

背景:生物力学实验有助于阐明为何半月板切除后会导致进行性的软骨病变。关节软骨退行性变的原因复杂,包括生物学、力学以及结构通路等。目的:研究内侧半月板后角撕裂行半月板部分切除后胫股关节接触面积、压力及半月板应变的变化。方法:取8具新鲜冷冻的混合品种的狗后肢膝关节标本,序贯进行以下半月板切除操作,采取百分比来计算每一样本半月板切除的范围:①内30%的内侧半月板后角撕裂。②内75%的内侧半月板后角撕裂。③内侧半月板后角完全切除。用双轴液压伺服生物材料测试实验机(MTS 858)进行生物力学测试。统计学比较采用SPSS 18.0软件进行组间比较。结果与结论:半月板组织切除越多,内侧和外侧胫股关节接触面积下降越明显,内侧半月板后角切除75%和全切后,内侧接触面积差异无显著性意义(P>0.05);内侧半月板后角完全切除之后,外侧接触面积显著减少。内侧半月板后角切除75%和全切之后,内侧间室的接触压力显著升高,与对照组相比差异有显著性意义(P<0.05),内侧半月板后角完全切除后外侧间室接触压力显著降低(P<0.05)。因为半月板组织的切除,其相应的应变下降,但是各组间差异无显著性意义。说明半月板切除多少决定术后半月板的生物力学功能;对于半月板撕裂,尤其是"红区"损伤,应尽量选择半月板缝合术,减少半月板切除范围,以避免或者延缓膝关节的退行性变。

BACKGROUND： Biomechanical experiments contribute to elucidate the progressive cartilage lesions following meniscectomy. The causes of articular cartUage degeneration are very complex, including biology, mechanics and structural pathway. OBJECTIVE： To observe the changes of tibiofemorel joint contact area, pressure and strain after serial meniscectomies of the caudal pole of the medial meniscus. METHODS： Unpaired pelvic limbs were harvested from eight hybrid adult dogs. All specimens underwent sequential meniscectomy, and the range of resected meniscus in each specimen was calculated as the percentage： a 30% radial width partial meniscectomy, a 75% radial width partial meniscectomy, and a segmental caudal pole hemi-meniscectomy. Biomechanical tests were performed using MTS 858. The difference between groups was compared with statistical analysis using SPSS 18.0 software. RESULTS AND CONCLUSION： More tissues removed after meniscectomy, more obviously the medial and lateral tibiofemoral joint contact area declined. After a 70% radial width meniscectomy and total meniscectomy, the medial contact area showed no significant difference （P 〉 0.05）; after the total meniscectomy, the lateral contact area was significantly reduced. After a 70% radial width meniscectomy and total meniscectomy, themedial contact pressure was significantly increased, showing significant differences compared with control group （P 〈 0.05）; after the total meniscectomy, the lateral contact pressure was significantly decreased （P 〈 0.058）. A meniscectomy resulted in a decrease in medial meniscal strain, but there was no significant difference between groups. The range of meniscectomy determines the biomechanical function post-operation; as for the meniscus tear, we suggest meniscal suture, to reduce the range of meniscectomy, avoid or delay the degeneration of knee joint.