腰椎小关节囊对腰椎稳定性影响的生物力学研究

Effects of Fibrous Capsule of Facet Joint on Lumbar Spinal Stability in Biomechanics

目的观察腰椎小关节囊对腰椎运动及稳定性的影响。方法取6具成人新鲜腰椎标本,每具标本均选取L4/5节段,制成6个L4/5功能单位(FSU)。包埋固定后在生物力学实验机上施10N.m的载荷,进行前屈、后伸、左右侧弯和左右旋转6个方向的运动范围测定,后逐级切断标本的单侧(左侧)及双侧小关节囊,重复生物力学实验测定,记录实验数据。结果切断两侧关节囊后,腰椎前屈运动范围从实验前的7.7°逐步增加到10.2°(P<0.05),对腰椎后伸运动范围变化无明显影响(P>0.05)。切断左侧小关节囊后,腰椎右侧弯运动范围较实验前增加[(7.2±10°)比(6.3±0.8°),P<0.05)],对左侧弯运动无明显影响(P>0.05)。切断两侧关节囊后,腰椎左侧弯角度从实验前的6.5°逐步增加到7.3°(P<0.05),右侧弯角度从6.3°逐步增加到7.2°(P<0.05)。切断单侧及双侧关节囊对FSU左/右旋转运动范围无明显影响(P>0.05)。结论腰椎小关节囊可影响腰椎前屈运动及腰椎侧弯时的稳定性。

Objective To observe the effect of fibrous capsule of facet joint on lumbar spinal motion and sta- bility with biomechanical methods. Methods The L4/5 segments from 6 freshly prepared adult lumbar specimens were selected to create 6 IA/5 functional spinal units （FSU）, followed by embedding and application of 10 N＇m torque using a biomechanical experimental machine. The range of motion （ROM） of each FSU was determined during motion in 6 directions （extension, flexion, left/right lateral bending, and left/right rotation）. The unilateral fibrous joint capsule （left side） and bilateral fibrous joint capsule were excised, and the biomechanical parameters of all were determined using the above-mentioned biomechanical machine. Results After cutting off the both sides of fibrous capsule of facet joint, the extension of FSU were extended from 7.7° to 10.2° （P〈0.05）, but no influence on flexion motion was observed （P〉0.05）. After cutting off the left side of fibrous capsule of facet joint, right lateral bending of FSU was increased from （6.3±0.8）° to （7.2±1.0）°, P〈0.05, while left laterl bending of FSU was not different （P〉0.05）. After cutting off the both sides of fibrous capsule of facet joint, left lateral bending of FSU was gradually increased from 6.5° to 7.3° （P〈0.05） and right lateral bending from 6.3° to 7.2° （P〈0.05）. No difference in left/right rotation of FSU was found before and after cutting off left lateral or bilateral fibrous capsule of facet jo- int （P〉0.05）. Conclusion The lumbar fibrous capsule of facet joint may impact the lumbar stability during flexion and left/right lateral bending.