Segmental vertebral motion in patients with lumbar disc herniation: an in vivo study / 中华骨科杂志

ABSTRACT

ObjectiveTo observe in vivo segmental lumbar motion in patients with lumbar disc herniation (LDH) during functional weight-bearing activities.MethodsFifteen patients with LDH at L4-5 were studied as experimental group.Ten healthy volunteers were recruited as control group.Three-dimension(3D) lumbar spine models of L3,L4 and L5 were reconstructed from thin section CT scans.Spine motions were then reproduced by matching lumbar spine models and images got from dual fluoroscopic imaging system (DFIS)under different motion state (standing,flexion-extension,left-right twisting and left-right bending).From local coordinate systems at the end plates,the motion of the cephalad vertebrae relative to the caudal vertebrae was calculated for vertebrae levels:L4-5 and L3-4.ResultsThe motion pattern at L4-5 was found to be altered.During flexion-extension,the migrations of the affected segments along the frontal axis,sagittal axis,vertical axis were similar with that of the control group,but the rotation angle along the frontal axis was significantly larger than that of the control group (P＜0.05).During left-right bending and left-right twisting,the migration and rotation angle along the frontal axis were significantly larger than those of control group.During flexionextension,the migrations of the neighboring segments (L3-4) along the three axes were larger than those of the control group,but there were no statistical significances.During left-right bending and left-right twisting,the migrations of the neighboring segments (L3-4) along the vertical axis were significantly larger than those of the control group (P＜0.05).ConclusionThe 3D lumbar motion pattern in LDH patient is different with that of normal people.For the affected segment,compared with the normal people,the range of flexion-extension motion and the translocation in left-right direction were significantly larger,but the rotation range along the vertical axis was smaller.