摘要
目的:通过生物力学测定了解穹顶形开窗减压术治疗腰椎管狭窄症对腰椎稳定性的影响。方法:手术处理于2005-04-05/05-02在中日合作连云港市骨科研究中心进行,生物力学实验于2005-07-01/07-07在上海生物力学工程研究所进行。选用30具正常新鲜成年雄性家猪腰椎L1～L6标本,剔除肌肉,保留韧带和关节囊,逐步处理分为3组:A组进行全椎板切除,B组行模拟穹顶形开窗减压术,C组不处理。以生物力学方法测试3组载荷-应变变化、应力-强度变化、载荷-位移变化、轴向刚度、扭转强度和刚度、极限力学性能等6项指标。结果:①载荷-应变测量结果:在生理载荷作用下,平均应变A,B组比C组分别高37%,18%(应变小说明脊柱稳定性好),A组比B组高22%。腰椎在后伸位和中立位应变较小,应变较大的是前屈位和侧屈位。中立位与前屈、后伸、侧屈位相比,分别相差19%,30%,19%。②应力-强度测量结果:A,B,C组平均应力强度为2.93,2.28,1.86MPa。椎体在中立位应力较小,为2.27MPa;后伸时应力强度最小,为1.58MPa;前屈应力强度为2.78MPa;侧屈2.80MPa。③载荷-位移变化的测量结果:A组比B组位移高34%,与C组比,穹顶形开窗减压仅增加21%的位移,而全椎板切除增加了48%,显示脊柱产生不稳定状态。腰椎在后伸位移最小,为2.02mm,侧屈位移为2.17mm,前屈位移较大,为2.26mm,中立位为1.73mm。④轴向刚度实验结果:A,B,C组平均为187,288,368N/mm,A,B组与C组相比较,分别相差22%和49%,A,B组相差35%。腰椎在后伸位轴向刚度264N/mm,比前屈234N/mm大12%。⑤扭转强度和刚度测量结果:C组与B组扭转强度相差12%,与A组相差39%,;A、B两组相比,B组强于A组30%。在同一扭转强度下,A,B组与C组相比较,分别相差4%和16%,B组优于A组。若在同一扭角下,A,B组与C组相比较,分别相差8%和21%。⑥极限力学性能试验结果:极限载荷和极限位移C组最强,其次是B组,A最差,两者与C相比分别相差15%和38%;屈服载荷B组优于A组,屈服位移也是如此。结论:进行穹顶形开窗减压的腰椎6项指标均接近未处理的正常腰椎,优于全椎板切除的腰椎。说明穹顶形开窗减压术对腰椎后部结构破坏少,对其稳定性影响小。
AIM： To comprehand the effect of decompression by domelike fenestration in the treatment of lumbar spinal stenosis on lumbar stability through biomechanical determination. METHODS： The operation was conducted in Japan-China cooperated Researching Center of Department of Orthopedics in Lianyugang from April 5^th to May 2^rd 2005 and the biomechanical experiment was performed in Shanghai Institute of Biomechanical engineering from July 1^st to July 7^th 2005. Lumbar L1-L6 specimens from thirty normal fresh adult pigs were selected, muscles were rejected with ligament and synovial capsule remained, gradually disposed, and then divided into three groups. Pigs in group A received rejection o.f the whole vertebral plate, pigs in group B received simulated decompression by domelike fenestration, pigs in group C received no disposal. Six indexes were tested such as load-strainning changes, stress-intensity changes, load-bias changes, rigidity and torsional intensity of axial direction, rigidity, limit michanical function etc. RESULTS： ①Determination of load-straining： Under the action of physiological load, mean straining in group A and B were respectively 37% and 18% higher than that in group C （Small straining suggested better spinal stability）, that in group A was 22 % higher than that in group B. Under different physiological motions, staining in posterior extending position and neutral position were small and that in anterior flexing position and lateral flexing position were big. Differences between neutral position and anterior flexing position, posterior extending position and lateral flexing position were respectively 19%, 30% and 19%.②Determination of strainning-intensity： Mean intensity of staining in group A, B, C were 2.93, 2.28, 1.86 MPa respectively. Straining in neural position of vertebral body was smaller, which was 2.27 MPa; Intensity of straining in posterior position was the smallest, which was 1.58 MPa; And that in anterior flexing position was 2.78 MPa; And was 2.80 MPa in lateral flexing position. ③Determination of load-bias changes： Bias in group A was 34% higher than that in group B. Compared with group C, bias with decompression by domelike fenestration only increased by 21%, while that with whole vertebral plate rejected increased by 48%, which indicated the unstable state of verterbral column. Bias of lumbar spine in posterior position under 4 kinds of physiological motions was the smallest, which was 2.02 mm and that in lateral flexing position was 2.17 mm, that in anterior flexing position was the biggest, which was 2.26 mm and was 1.73 mm in neural position. ④ Experimental result of rigidity of axial direction： Mean of group A, B, C were 187, 288, 368 N/mm.Compared group A, B with group C, differences were 22% and 49% respectively and difference between group A and B was 35%. Under 4 different kinds of physiological motions, rigidity of axial direction in posterior flexing position of lumbar spine was 264 N/mm, which was 12% bigger than that in anterior flexing position. ⑤Determination of torsional intensity and rigidity： differences in torsional intensity between group C and B was 12% and was 39% between group A and C; That in group B was 30% stronger than that of group A. At the same torsional intensity, differences between group A, B and group C were 8% and 21% respectively.⑥ Testing results of the limit of mechanical function： Limit load and limit bias in group C were the stronggest, then was group B, those of group A were the poorest. Differences between group B, A and group C were 15% and 38% respectively; Zero load in group B was superior to that of group A, so did the bias. CONCLUSION： Six indexes of lumbar spine after decompression by domelike fenestration are near to those of untreated normal lumbar spine and are superior to those with whole vertebral plate rejected, which indicates that there are less destructions of decompression by domelike fenestration on posterior structure of lumbar spine and effect on stability is small.
出处
《中国临床康复》
CSCD
北大核心
2006年第12期86-89,共4页
Chinese Journal of Clinical Rehabilitation
