兔腰椎小关节退变在退行性腰椎侧凸发病中的作用

Lumbar facet joint degeneration contributes to degenerative lumbar scoliosis induced by asymmetric stress in rabbits

目的探讨在不对称应力作用下腰椎小关节退变在退行性腰椎侧凸发生发展过程中的作用。方法 36只新西兰白兔被随机分为椎间盘退变组(A组),小关节退变组(B组),椎间盘及小关节退变组(C组),12只/组。A组通过穿刺抽吸髓核组织产生椎间盘退变,B组通过切除左侧小关节囊造成小关节退变,C组同时接受A组和B组的处理。分别对三组的L3/4、L4/5、L5/6左侧小关节加载拉簧,分别于术后3月、6月拍正侧位片测量腰椎侧凸Cobb角,术后6月取腰椎小关节,采用番红O-快绿染色,进行Mankin评分判断软骨退变程度。结果不同组间腰椎侧凸Cobb角有显著性差异(F=24.865,P=0.000)。组内比较,各组6月时Cobb角较3月时更大(均P<0.05);同一时间点,C组较A、B组Cobb角更大(均P<0.05),但A、B组间Cobb角无显著性差异(均P>0.05)。不同组间小关节软骨退变程度Mankin评分有显著性差异(F=22.009,P=0.000),C组较A、B组小关节软骨退变严重(P<0.05),B组较A组小关节软骨退变严重(P<0.05)。结论腰椎小关节退变是退行性腰椎侧凸发生发展的重要因素,椎间盘、腰椎小关节不同程度的退变可导致腰椎发生侧凸,腰椎侧凸又会加重椎间盘、小关节退变和受力的不对称,形成恶性循环,从而导致腰椎侧凸的进一步发展。

Objective To investigate the role of lumbar facet joint degeneration in the development of degenerative lumbar scoliosis caused by asymmetric stress. Methods Thirty-six New Zealand white rabbits were randomly divided into 3 groups(n=12): Group A with aspiration of the nucleus pulposus to induce disc degeneration;Group B with removal of the left capsule from the facet joints at L3/4 to L5/6 to induce degeneration;and Group C with both treatments. Springs were deployed on the left adjacent facets at L3/4, L5/6 and L5/6 to stress the facet joints. Serial radiographs were taken at 3 and 6 months, and the facet joint tissues were sampled at 6 months for Safranin O-fast green staining to assess the severity of cartilage degeneration based on the Mankin score. Results The Cobb angle differed significantly among the 3 groups(F=24.865, P=0.000). In all the groups, the Cobb angles at 6 months increased significantly as compared with that at 3 months(P<0.05). The Cobb angles were significantly greater in group C than in the other 2 groups at both 3 and 6 months(P<0.05) but showed no significant difference between Groups A and B(P>0.05). The severity of facet joint degeneration also differed significantly among the 3 groups(F=22.009, P=0.000), and was the most severe in group C(P<0.05);facet joint degeneration was more severe in group B than in group A(P<0.05). Conclusion Facet joint degeneration is an important factor that contributes to the development of degenerative lumbar scoliosis. Disc degeneration and facet joints degeneration can lead to lumbar scoliosis, which in turn aggravates disc degeneration, facet joints degeneration and asymmetric stress, thus forming a vicious circle to further exacerbate lumbar scoliosis.