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Objective To investigate the stability of lumbar single?level dynamicly fixed by socket track pedicle screws after decompression. Methods Socket track pedicle screws are made of titanium?alloy, swing like universal screw within the scope of 18° in the sagittal plane and 8° in the horizontal plane. Motion constraints were due to the hole which the screw goes through. Six pig spines (L1-5) were tested by applying a pure moment of 4.018 Nm in 3 directions of loading. The range of motion (ROM) of the following groups underwent different surgical procedures was measured:(1) intact;(2) dynamic fixation 1 (decompres?sion by total laminectomy and instrumentation with socket track pedicle screws); (3) dynamic fixation 2 (decompression by total laminectomy and bilateral facetectomy while instrumentation with socket track pedicle screws);( 4) instability resulted from decom?pression (decompression by total laminectomy plus bilateral facetectomy without any rod);(5) hybrid fixation (decompression by to?tal laminectomy and bilateral facetectomy while instrumentation with 2 socket track pedicle screws connected with 2 unilateral pedicle screws ). Results Compared with the intact specimens (in flexion, extension, lateral bending and rotation, corresponding angular displacements were 1.84°±0.75°, 1.55°±0.34°, 2.2°±1.07°, 2.06°±0.76° respectively), the ROM of segment L3, 4 of each group were significantly restricted except for axial rotation. In flexion, extension and lateral bending, the ROM was reduced to 0.71°±0.39°, 0.46°±0.18°, 0.85°±0.66° in dynamic fixation 1 group;0.79°±0.43°, 0.71°±0.20°, 1.17°±0.48° in dynamic fixation 2 group and 0.63°±0.50°, 0.37°±0.19°, 0.54°±0.60° in hybrid fixation group. The rotation ROM of dynamic fixation 1 group and hy?brid fixation group were decreased to 1.50°±0.64° and 1.22°±0.36°, whereas the ROM of dynamic fixation 2 had a non?significant reduction to 1.85°±0.67°. The extension and rotation ROM of dynamic fixation 2 increased significantly comparing to dynamic fixa?tion 1 group; the extension, lateral bending and axial rotation ROM of hybrid fixation group were reduced comparing to the state of dynamic fixation 2 group. Conclusion The dynamic instrumentation of single?level lumbar spine with socket track pedicle screws could offer stability in all directions. The flexion, extension, lateral bending and rotation ROM of spine with dynamic instru?mentation after total laminectomy and bilateral facetectomy could be reduced.
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Objective To explore the clinical efficacy and application value of hemivertebra resection for treating congenital ky‐phoscoliosis .Methods 30 cases of congenital kyphoscoliosis and hemivertebral deformity in our hospital from January 2011 to Jan‐uary 2013 were selected as the research subjects .Among them ,12 cases of simple vertebral and non‐structural bending were per‐formed the posterior hemivertebral resection and short segment pedicle screw fixation ;3 cases of complicating lordosis and hemiver‐tebral protruding to the ventral side were performed the anterior hemivertebral resection and bone graft fusion fixation ;15 cases of complicating structural compensatory curve were performed the posterior transpedicle hemivertebral resection and compensatory bend long segment fixation and fusion .The clinical effects of surgical treatment for all patients were performed the comparative a‐nalysis .Results The mean postoperative kyphosis Cobb angle and the average final follow‐up Cobb angle were (8 .6 ± 3 .14) °and (11 .2 ± 7 .23) °respectively .The ultimate orthopedic rate of kyphosis was 58 .6% ;the average postoperative Cobb angle and and the average final follow‐up Cobb angle of scoliosis were (12 .8 ± 5 .47)°and (16 .2 ± 6 .24)°respectively ,the final orthopedic rate of scoliosis was 66 .5% .The mean Cobb angle of kyphosis and scoliosis after operation was significantly less than that before opera‐tion ,the difference was statistically significant(P< 0 .05) .Kyphosis and scoliosis were significantly improved .No significant post‐operative complications occurred .The effects were satisfied by the patients .Conclusion The hemivertebral resection has significant effect for treating congenital kyphoscoliosis with high kyphoscoliosis orthopedic rate and is worthy of further clinical study .
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Objective To provide the morphological evidence for sensory pathway by the repair of dorsal root (DR) in which received transected and anastomosed with central processes (DR) and peripheral processes (spinal nerve) respectively. Methods 74 SD rats were divided into three groups randomly. Group A: the distal ending of L6 DR was sutured to the proximal ending of the L4 DR in right side. Group B: the postganglionic spinal nerve of L4 was cut at a point 2 mm to intervertebral foramen and its proximal stump was reconnected to the distal ending of L6 DR in right side. Group C: under the same operative manipulation on group B, but no anastomosis was performed to serve as the sham operation group. The left side was kept intact and served as a normal control in all groups. The repairing results of DR axonal regeneration were evaluated at 3 months after operation by retrograde tracing, the density of positive Calcitonin gene-related peptide (CGRP) axon in dorsal root entry zone (DREZ), survival rate of neurons in DR ganglia and posterior horn, light and transmission electron microscope. Results HRP retrograde tracing demonstrated axonal axoplasmic transport of regenerative nerve recovered well in group B. Regenerative fibers were found. There was no difference between group A or B and normal control with regard to the number of myelinated axons and the thickness of myelin. Regenerating axon stop at the DREZ in group A and the density of positive CGRP were lower than those in group B and normal control. Survival rate of neurons in L6 DR ganglia had no difference among all groups. However, in posterior horn, a significant increase in death was seen in group A and sham group. Conclusion The ability of axonal regeneration was effective and with no disservice to neurons in posterior horn following anastomosis of postganglionic spinal nerve and dorsal root, by which axoplasmic transport across the DREZ into the spinal cord.
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Objective To discuss the value of the posterior long segments pedicle screws fixation in surgical treatment of thoracolumbar fracture-dislocation,and summarize the experience.Method s We reviewed the clinical information of 27 cases of thoracolumbar fracture-dislocation since July 2007 to March 2010; all the cases were treated with the posterior long segments pedicle screws fixation.In these cases,20were male,7 were female.And the age ranged from 18 to 58 years old (average age was 35 years).The posterior approach was used,and the pedicle screws were inserted into the 2 vertebrae above and below the fractured vertebrae.Posterior decompression and bone grafts for fusion were also accomplished during the operation.Results Follow-up ranged from 7 to 25 months,averaging 14 months.Completely restoration of the dislocation was got in 25 cases and the spine sequence resumed to nearly normal.One case with lateral dislocation failed to complete correction; another 1 case operated 20 days after surgery failed to complete correction of forward dislocation.At the last follow-up,the mean Cobb angle loss was 3 degrees,the height of the vertebral had obvious loss compared with that of post-operation.The loosen of screw nut was found during the follow-up,but no dislocation and secondary deformity were observed after fixation.There was no death,no infection.Conclusions The technique of posterior long segments pedicle screw fixation is of great value in the clinical applications,since it has the following advantages:the operation is simple,trauma is small,the fixation is firm,good restoration of fracture and dislocations can be easily got,and most importantly,it can effectively prevent long-term vertebral height loss and the backward protruding deformity.
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Objective To summarize and explore the clinical value of selective partial neurotomy of muscular branch of triceps in the treatment of spastic talipes equines.Methods Forty-two cases were included in our study from Aug.2000 to Des.2007,all these cases accepted the operation of selective partial neurotomy muscular branch of triceps.In this study,29 cases were male,13 cases were female.Muscle force of legs,muscular tension,pathologic reflex,gesture and function of legs after operation were compared with that of before operation.Results The mean fallow-up was 18 months.During the fallow-up of this study,muscular tension degraded,the function of ankle joints and the gesture of extremitas inferior were improved obviously.The effective power was about 90% after 12 months follow-up.Conclusions Selective partial neurotomy of muscular branch of triceps is a effective method for the treatment of spastic talipes equines.The operation procedure is simple and effective,and could be generalized in the primary level hospital.