ABSTRACT
Objective To investigate the effect of cervical spinous process fracture with posterior ligamentous complex (PLC) injury on biomechanical stability of the goat cervical spine specimen in vitro, and evaluate the role of posterior structure in maintaining the stability of cervical spine. Methods Twenty-four fresh goat cervical spine C3-6 specimens were randomly and evenly divided into 3 groups: control group (group A), simple cervical spinous process fracture group (group B) and cervical spinous process fracture with PLC injury group (group C). Under loading of 1.5 N·m torque, the range of motion (ROM) in each group was respectively measured under 6 working conditions: flexion, extension, lateral bending and axial rotation, and the ROM differences among 3 groups were compared by using one-way ANOVA analysis. Results Simple cervical spinous process fracture had little effect on the stability of cervical spine and there was no significant difference in ROM between group B and control group (P>0.05) under all working conditions. Compared with control group, the ROM in flexion, extension and axial rotation significantly increased in group C (P0.05). Conclusions Simple cervical spinous process fracture does not affect the overall stability of cervical spine. Cervical spinous process fracture with PLC injury is more likely to cause cervical instability than simple cervical spinous process fracture, and surgical intervention is required in cervical spinous process fracture with PLC injury.
ABSTRACT
Objective To investigate the effect of cervical spinous process fracture with posterior ligamentous complex (PLC) injury on biomechanical stability of the goat cervical spine specimen in vitro,and evaluate the role of posterior structure in maintaining the stability of cervical spine.Methods Twenty-four fresh goat cervical spine C3-6 specimens were randomly and evenly divided into 3 groups:control group (group A),simple cervical spinous process fracture group (group B) and cervical spinous process fracture with PLC injury group (group C).Under loading of 1.5 N · m torque,the range of motion (ROM) in each group was respectively measured under 6 working conditions:flexion,extension,lateral bending and axial rotation,and the ROM differences among 3 groups were compared by using one-way ANOVA analysis.Results Simple cervical spinous process fracture had little effect on the stability of cervical spine and there was no significant difference in ROM between group B and control group (P ＞ 0.05) under all working conditions.Compared with control group,the ROM in flexion,extension and axial rotation significantly increased in group C (P ＜ 0.05),and no significant ROM difference was found in lateral bending between control group and group C (P ＞ 0.05).Conclusions Simple cervical spinous process fracture does not affect the overall stability of cervical spine.Cervical spinous process fracture with PLC injury is more likely to cause cervical instability than simple cervical spinous process fracture,and surgical intervention is required in cervical spinous process fracture with PLC injury.
ABSTRACT
Objective To investigate the effect from sequential removal of posterior ligamentous complex (PLC) on stability of injured thoracolumbar spine, and verify the role of supraspinous ligaments in maintaining stability of injured thoracolumbar spine complex. Methods Eight fresh human thoracolumbar specimens (T11-L3) were selected, and 1/3 of the L1 vertebral body was resected for "V" shape. The specimens were then mounted on the universal testing machine and subjected flexion and compression to make a fracture in L1. PLC in T12-L1 segment was then resected in a sequential manner from facet capsular ligament (FCL), interspinous ligament (ISL), supraspinous ligament (SSL) to ligamentum flavum (LF). The range of motion (ROM) and neutral zone (NZ) of the T12-L1 segment under flexion, extension, lateral bending and rotation movement were measured at each ligament removal step. Results Under flexion and extension, ROM and NZ presented a significant increase after fracture and removal of SSL. Under right lateral bending, ROM increased sharply after reduction of vertebrae and FCL, while the NZ showed a slight increase. Under left axial rotation, removal of vertebrae and FCL resulted in a significant increase in ROM, while the NZ showed no significant increase. Conclusions After removal of SSL, the stability of the T12-L1 segment decreases sharply, especially under flexion motion, and SSL is the pivotal ligament for PLC to maintain the stability of thoracolumbar spine.