ABSTRACT
BACKGROUND:Photoelectric navigation-aided percutaneous pedicle screw placement has been developed extensively,but its accuracy,safety and effectiveness have not yet been confirmed by evidence-based medicine.OBJECTIVE:To compare the curative efficacy of photoelectric navigation-aided percutaneous pedicle screw placement and traditional open posterior pedicle screw fixation for thoracolumbar fractures.METHODS:Sixty patients with thoracolumbar fractures were equivalently randomized to treatment and control groups and then underwent photoelectric navigation-aided percutaneous pedicle screw placement and traditional open posterior pedicle screw fixation,respectively.The perioperative indexes,imaging indexes,function recovery and incidence of complications were compared between two groups.RESULTS AND CONCLUSION:(1) The Visual Analogue Scale scores,intraoperative blood loss,radiant times,and hospitalization time in the treatment group were significantly less than those in the control group (P ＜ 0.05).(2) The operation time did not differ significantly between two groups (P ＞ 0.05).(3) The postoperative sagittal Cobb angle,and percentage of anterior height in the vertebral body in the two groups were significantly improved compared with those before surgery (P ＜ 0.05),but all above imaging indexes showed no significant differences between two groups (P ＞ 0.05).The endplate-screw angle in the treatment group was significantly less than that in the control group (P ＜ 0.05).(5) The excellent and good rate of placement in the treatment group was significantly higher than that in the control group (P ＜ 0.05).(6) These results suggest that compared with the traditional open posterior pedicle screw fixation,the photoelectric navigation-aided percutaneous pedicle screw placement exhibits high placement accuracy,less radiant times,less trauma,less blood loss and rapid functional recovery.
ABSTRACT
BACKGROUND:BioFlex system as a new pedicle screw fixation of dynamic stabilization device has less been reported concerning its biomechanics. OBJECTIVE:To study the effect of BioFlex system fixation at different decompression ranges on disc stress at adjacent segments. METHODS:Eight samples of fresh calf spines were used. Under physiologic axial loads (500, 900, 2 300 N), electronic universal testing machine was used to simulate the lumbar spine at three physiological states (standing, sitting and bending, standing on a portable 20 kg weight and bending). Progressive decompression modeling for each specimen and dividing into five groups:(1) complete status group;(2) complete status+BioFlex group;(3) partial laminectomy+BioFlex group;(4) 1/2 medial facetectomy+BioFlex group;(5) total facetectomy+BioFlex group. Strain gauges were used to record the stress of disc annulus. Electronic universal testing machine was used to record load-displacement curve and calculate stiffness. RESULTS AND CONCLUSION:(1) The stress of the adjacent segment of the intervertebral disc increased with the expansion of the range of decompression. Compared with the complete status, stress obviously increased after BioFlex fixation, showing significant differences (P0.05). (2) Axial stiffness reduced with the expansion of the range of decompression. Compared with the complete status, axial stiffness noticeably increased after BioFlex fixation. The difference was not significant among four kinds of reconstruction structures. (3) These findings confirmed that after BioFlex fixation, with the expansion of the range of decompression, the stress of adjacent segments of intervertebral disc gradual y increased, but different ranges of decompression cannot affect the stiffness of reconstruction structure.
ABSTRACT
ObjectiveTo compare the therapeutic effects of percutaneous cervical discectomy (PCD group),percutaneous cervical disc nucleoplasty(PCN) and the association of them (PCDN) for the treatment of cervical intervertebral disk displacement and instability of cervical vertebral column.Methods From February 2003 to April 2011,171 consecutive patients with cervical disc herniation have presented at the authors' hospital and were retrospectively studied.The average age of patients was 47.8 years(ranged,21-74).Ninety-seven cases were treated with PCD,50 cases with PCN,and the other 24 cases with PCDN.Clinical result and the stability of cervical vertebral column after operation were evaluated and compared among the 3 groups.ResultsAll cases had been followed up for a median of 4.1 years.There was significant difference in the pre- and post-operation the Japanese Orthopaedic Association(JOA) scoring system on within 3groups (PCD:t=21.85,P＜0.05; PCN:t=14.50,P＜0.05; PCDN:t=8.56,P＜0.05).All cases had been successfully operated.There was no significant difference between groups among the 3 groups in terms of the clinical outcomes(The recovery rate of JOA standard evaluation,F=2.19,P=0.12).According to Odom criteria,the excellent and good rate are as follows:81.35％ in PCD,82.44％ in PCN,83.19％ in PCDN,respectively.There was no significant difference between groups among the 3 groups in terms of the clinical success rate (P＞0.05).There was no instability of cervical vertebral column cases in 3 groups after operation(P＞0.05),and no significant difference was found in terms of cervical vertebral column stability in pre- and post-operation in each group.ConclusionAll the three operations including PCN,PCD and PCDN are safe,minimally invasive spine surgery for the treatment of cervical intervertebral disk displacement; they achieve good clinical outcomes and there are no difference on the stability of cervical vertebral column between preoperation and postoperation.