Objective To assess the outcomes of pedicle subtration osteotomy and short-segment pedicle screw internal fixation in kyphosisdeformity. Methods From June 2001 to November 2003, 16 cases of kyphosis deformity were treated with pedicle subtration osteotomy and short-segment pedicle screw internal fixation, including 11 males and 5 females and aging 24-51 years. The kyphosis deformity was caused by ankylosing spondylitis in 12 cases, old lumbothoracic fracturedislocation in 2 cases, and vertebral dysplasia in 2 cases. The disease course was 7-25 years with an average of 12.8years. The whole spine radiographs were taken pre-and postoperatively. The sagittal balance was assessed by measuring thoracic kyphosis angle, lumbar lordosis angle, acrohorizontal angle and distance between posterosuperior point of S1and the vertical line. The clinical outcomes were assessed by Bridwell-Dewald scale for spinal disorders. Results The mean follow-up period was25.6 months. The mean bleeding was 1 100 ml. Satisfactory bone graft healing was achieved at final follow-up. Complications were paralytic intestinal obstruction in 1 case, dura laceration in 1 case, and temporary lower limb paralysis in 2 cases. Final follow-up radiograph showed an increase in lumbar lordosis angle from 9.6±16.4° to 42.6±14.3°(P＜0.05), whereas thoracic kyphosis angle remained relative stable. The distance between posterosuperior point of S1 and the vertical line was decreased from 97.5±45.6 mm to 10.7±9.6 mm(P＜0.05). Satisfactory clinical outcome was achieved by evaluating the changes of pain, social and working status. Conclusion Pedicle subtraction osteotomy and short-segment pedicle screw internal fixation is effective for correction of kyphosis deformity.
Objective To evaluate the accuracy of pedicle guide device for the placement of the pedicle screws. Methods Pedicle guide device was designed and made for the anatomical trait of pedicle. The 3-Danatomical data of the thoracic pedicles were measured by multislice spiral CT in two embalmed human cadaveric thoracic pedicles spine(T1 -T10). Depending on transverse section angle(TSA) and sagittal section angle(SSA) of pedicle axis, the degree of horizontal dial and sagittal dial were adjusted in the guide device. The screws wereinserted bilaterally in the thoracic pedicles by using the device. After pulling the screws out, the pathways were filled with contrast media. The TSA and SSA of developed pathways were measured. Results Analysis of the difference between pedicle axis and developed pathway was of no statistical significance(P＞0.05). Conclusion The guide device could be easilyoperated and guarantee high accuracy of the pathways of screws and the incidence of pedicle penetration could be significantly reduced.
Objective To explore the feasibilities, methods, outcomes and indications of atlas pedicle screw system fixation and fusion for the treatment of upper cervical diseases. Methods From October 2004 to January 2006, 17 patients with upper cervical diseases were treated with atlas pedicle screw system fixation and fusion. There were 13 males and 4 females, ageing 19 to 52 years. Of 17 cases, there were 14 cases of atlantoaxial dislocation(including 3 cases of congenital odontoid disconnection，4 cases of old odontoid fracture，2 cases of new odontoid fracture(typeⅡC), 3 cases of rupture of the transverse ligament, and 2 cases of atlas fracture； 2 cases of tumor of C2; 1case of giant neurilemoma of C2,3 with instability after the resection oftumors. JOA score before operation was 8.3±3.0. Results The mean operative time and bleeding amount were 2.7 hours (2.1-3.4 hours) and 490 ml (300-750 ml) respectively. No injuries to the vertebral artery and spinal cord were observed. The medial-superior cortex of lateral mass was penetrated by 1 C1 screw approximately 3 mmwithout affecting occipito-atlantal motions. All patients were followed up 3-18 months. The clinical symptoms were improved in some extents and the screws were verified to be in a proper position, no breakage or loosening of screw and rob occurred. All patients achieved a solid bone fusion after 3-6 months. JOA score 3 months after operation was14.6±2.2. JOA improvement rates were 73%-91%(mean 82%). Conclusion The atlas pedicle screw system fixation and fusion is feasible for the treatment of upper cervical diseases and has betteroutcomes, wider indications if conducted properly.
ObjectiveTo explore the effectiveness percutaneous monoaxial screw combined with polyaxial pedical screw for treating thoracolumbar fracture by comparing with simple polyaxial pedicle screw fixation. MethodsBetween January 2012 and June 2014, 56 cases of thoracolumbar fractures were treated by percutaneous pedicle screw fixation, the clinical data were retrospectively analyzed. Of 56 cases, 30 were treated with percutaneous monoaxial screw combined with percutaneous polyaxial pedical screw fixation (group A), 26 patients with only percutaneous polyaxial pedicle screw fixation (group B). There was no significant difference in gender, age, body mass index, injury causes, time from injury to admission, involved segments, fracture type, and preoperative American Spinal Injury Association (ASIA) stage, visual analogue scale (VAS), the anterior height of the injured vertebrae, Cobb angle, and sagittal index between 2 groups (P>0.05). The operation time, intraoperative blood loss, and complications were recorded and compared between the 2 groups. The VAS score was used to evaluate the improvement of the pain. The sagittal kyphosis Cobb angle, the anterior height of the injured vertebrae, sagittal index, and the average correction (difference between 3 days after oeration and preoperation) and loss degrees (difference between last follow-up and 3 days after operation) were measured on the X-ray films at preoperation, 3 days after operation, and last follow-up. ResultsIncision healing at stage I was obtained, no related complications occurred. The operation time and intraoperative blood loss showed no significant difference between 2 groups (P>0.05). The patients were followed up 20-42 months (mean, 32 months) in group A and 21-44 months (mean, 30 months) in group B. VAS score of group A was significantly lower than that of group B at 3 days after operation (t=-2.277, P=0.027), but no significant difference was found at last follow-up (t=-0.289, P=0.774). X-ray examination showed good position of internal fixation, with no broken nails or exit of nail. There were significant differences in the anterior height of the injured vertebrae, Cobb angle, and sagittal index between at preoperation and at 3 days and last follow-up, and between at 3 days and last follow-up in 2 groups (P<0.05). The anterior height of the injured vertebrae, Cobb angle, and sagittal index of group A were significantly better than those of group B at 3 days and last follow-up (P<0.05), and correction degree were significantly higher than those of group B (P<0.05), but loss degree was not significant between 2 groups (P>0.05). ConclusionPercutaneous monoaxial screw combined with polyaxial pedicle screw fixation is better than simply polyaxial pedicle screw in effects of treating thoracolumbar fracture under the premise of strictly holding indications.
ObjectiveTo investigate the effectiveness of pedicle screw internal fixation for the atlantoaxial instability of children. MethodsBetween July 2005 and January 2012, 19 cases of atlantoaxial instability were treated, included 10 boys and 9 girls with an average age of 7.5 years (range, 4-15 years). The X-ray films, CT, and MRI examinations of the cervical spine showed craniocervical malformation in 9 cases, congenital os odontoideum in 3 cases, odontoid fracture (type Ⅱ) in 1 case, disruption of transverse ligament in 2 cases, atlantoaxial fracture and dislocation in 4 cases; and spinal cord injury in 8 cases, according to the American Spinal Cord Injury Association (ASIA) impairment scale, 1 case was rated as grade B, 2 as grade C, and 5 as grade D. Preoperative skull traction was performed routinely on all cases, and complete reduction was achieved in 17 cases, no reduction in 2 cases. In 17 patients who achieved complete reduction, pedicle screw internal fixation was used through posterior approach, including occipitocervical fusion and fixation in 5 cases, and atlantoaxial fusion and fixation in 12 cases; in 2 patients with no reduction, pedicle screw internal fixation was used through posterior approach (atlantoaxial fusion and fixation) after release by transoral approach. ResultsThe operation was successfully performed in all patients. The mean operation time was 89 minutes; the mean intraoperative blood loss was 95 mL; the mean postoperative drainage volume was 73 mL; and the mean hospitalization days were 14 days. The patients were followed up 6-27 months (mean, 18.3 months). Satisfactory atlantoaxial fusion was obtained, and bone fusion was obtained at 3-7 months after operation (mean, 4.5 months). No breakage of screw or rods and re-dislocation occurred during follow-up. At last follow-up, the cervical range of motion (CROM) of the left and right rotation were (62.0±5.9)°and (63.9±3.8)°respectively in 5 patients receiving occipitocervical fusion and fixation, showing significant difference when compared with the values of normal children[(72.3±7.0)°and (74.1±7.6)°, respectively] at the same age (t=-3.915, P=0.018; t=-5.954, P=0.004). The CROM of the left and right rotation were (70.5±5.8)°and (72.7±4.9)°respectively in 14 patients receiving atlantoaxial fusion and fixation, showing no significant difference when compared with normal children at the same age (t=-1.417, P=0.180; t=-1.021, P=0.323). The visual analogue scale (VAS) score was significantly decreased from 7.8±1.1 at pre-operation to 3.5±0.8 at last follow-up (t=17.267, P=0.000). In 8 cases having spinal cord injury, 2 cases were rated as grade C, 1 case as grade D, and 5 cases as grade E according to ASIA impairment scale. ConclusionTechnique of pedicle screw internal fixation has been proven to be an effective treatment for the atlantoaxial instability of children. It plays an important part in relieving pain and limitation of the cervical region.
Objective To ascertain whether augmentation pedicle screw fixation with polymethylmethacrylate (PMMA) can enhance the stability of unstable thoracolumbar burst fractures of osteoporotic spine. Methods Six fresh frozen female osteoporotic spines (T10-L5) were harvested and an anterior and posterior columnunstable model of L1 was made. Each specimen was fixated with plate and the stability test were performed by flexion, extension, axial rotation and lateral bending. The test of fatigue was done with MTS 858.The tests were repeated after screws were augmented with PMMA. To compare the biomechanical stability of 6 different conditions:○anormal specimens(control), ○bdefectmodel fixed with plate, not augmented and not fatigued, ○cafter fatigued, not augmented, ○dscrews augmented with PMMA, not fatigued, ○e after augmented and fatigued. ResultsIn ○b,○d and ○e conditions, the ranges of motion(ROM) were 6.23±1.56，4.49±1.00，4.46±1.83 inflexion and 6.60±1.80，4.41±0.82，4.46±1.83 in extension. There was no significant difference (Pgt;0.05), they were significantly smaller than those in ○a and ○c conditions (8.75±1.88，1.47±2.25 and 8.92±2.97，12.24±3.08) (Plt;0.01).Conclusion The results demonstrated that augmentation pedicle screws fixation with PMMA can increase the stability of osteoporotic spine.
ObjectiveTo explore the application value of thin CT angiography (CTA) of pedicle sagittal plane of axis for preoperative evaluation planning pedicle screw placement.MethodsBetween February 2016 and August 2017, 34 patients (68 pedicles) who underwent thin CTA scan before posterior axial surgery were retrospectively analyzed. The vertebral artery development was statistically analyzed. The continuous layers of transverse process hole pedicle height more than or equal to 4 mm (f) were measured and read. The axial fixation methods, clinical manifestations of vertebral artery and spinal cord injury and the bone union of fractures or implants were recorded. Postoperative results of pedicle screws were evaluated by CT scan.ResultsThe right sides of 8 cases and the left sides of 18 cases were dominant vertebral arteries, and equilibrium was reached in 8 cases; f>9 layers were found in 16 pedicles,f=9 layers in 27 pedicles, f=8 layers in 17 pedicles, and f<8 layers in 8 pedicles. The 43 pedicles off≥9 layers used pedicle screw fixation; in the 17 pedicles of f=8 layers, 16 used pedicle screw fixation, and the other one used laminar screw fixation; in the 8 pedicles of f<8 layers, 4 used pedicle screw fixation, and the other 4 used laminar screw fixation. A self-defined pedicle screw grading system was used to evaluate the excellence, and the result showed that,f>9 layers: 14 pedicles were class A, 2 were class B, none was class C;f=9 layers: 16 pedicles were class A, 7 were class B, 4 were class C; f=8 layers: 3 pedicles were class A, 5 were class B, 8 were class C; f<8 layers: none was pedicles class A or class B, 4 were class C. The other 4 lamina screws fixation didn’'t invade the spinal canal. One case of pedicle class C showed clinical manifestations of mild dizziness and drowsiness. The patients were followed up for 6-11 months with an average of (8±3) months, and the fracture or bone graft fusion were observed after 6 months of following-up.ConclusionBased on preoperative CTA thin layer scanning, through measuring and reading continuous layers of transverse process hole pedicle height more than or equal to 4 mm, can effectively judge the security of axial pedicle screws in order to subsequently choose the reasonable operation methods so as to improve success rate and decrease surgical risk.
Objective To develop a high-accuracy, better-safety and low-cost cervical pedicle locator system for guiding cervical pedicle screw placement. Methods Cervical pedicle screw locator system was made of stainless steel. Ten cervical specimens from voluntary donation were divided into two groups according to compatibil ity design: control group inwhich 60 screws were planted into C2-7 by free hand; and experimental group in which 60 screws were planted into C2-7 under the guidance of three-dimensional locator system. The condition of screw insertion was observed and the accuracy was evaluated by the integrity of pedicle walls. Results In the control group, 32 screws (53.33%) were placed inside the pedicles and 28 (46.67%) were outside; 9 screws (15.00%) led to nerve root injury, 5 screws (8.33%) caused vertebral artery injury and no spinal cord injury occurred; and the qual ification ratio of screw insertion was 76.67% (excellent 32, fair 14, poor 14). While in the experimental group, 54 screws (90.00%) were placed inside the pedicles and 6 (10.00%) were outside; 1 screw (1.67%) caused vertebral artery injury and no nerve root injury and spinal cord injury occurred; and the qual ification ratio of screw insertion was 98.33% (excellent 54, fair 5, poor 1). There was significant difference between the two groups (P lt; 0.05). Conclusion Cervical pedicle screw locator system has the advantages of easy manipulation, high accuracy of screw placement and low cost. With further study, it can be appl ied to the cl inical.
Objective To compare the curative effect of posterior lumbar interbody fusion with autologous il iac crest to that of interbody fusion cage for adult instabil ity of lower lumbar. Methods From February 2003 to October 2006,60 inpatients with lower lumbar instabil ity were treated. Patients were randomized into 2 groups: bone-graft group (n=28) was treated with posterior lumbar interbody fusion with two autologous il iac crests, while cage group (n=32) was treated with posterior lumbar interbody fusion with two quadrate cages. In the bone-graft group, 17 males and 11 females aged (52.78 ± 10.50) years with 3-16 months of disease course, there were 12 cases of degenerative instabil ity, 14 isthmus sl it ol isthe and 2 iatrogenic instabil ity, including 1 case of L3,4, 17 cases of L4,5 and 10 cases of L5, S1. Relative disc space height was (23.24 ± 6.62) mm, disc space activity was (10.50 ± 5.07)º, sagittal saw sl ippage distance was (4.50 ± 1.15) mm and the JOA score was 18.56 ± 2.68. In the cage group, 19 males and 13 females aged (51.75 ± 10.44) years with 3.5-14.0 months of disease course, there were 16 cases of degenerative instabil ity, 14 isthmus sl it ol isthe and 2 iatrogenic instabil ity, including 16 cases of L4,5 and 16 cases of L5, S1. Relative disc space height was (24.34 ± 7.22) mm, disc space activity was (11.12 ± 5.67)º, sagittal saw sl ippage distance was (4.38 ± 0.75) mm and the JOA score was 19.00 ± 4.12. There was no significant difference between the two groups in termsof age, gender, JOA score, disc space activity and relative disc space height preoperatively (P gt; 0.05). Results All patients received the follow-up at the 1st, 3rd, 6th and 12th month postoperatively. There was no significant difference in operation time and hemorrhage amount between the two groups (P gt; 0.05), but significant difference in the cost of operation (P lt; 0.01). Two cases in the bone-graft group suffered donor site pain and received no treatment. Three cases in the bone-graft group and 2 cases in the cage group had symptom of nerve injury 1-2 days after surgery, which were cured after expectant treatment. There were no pseudoarticulation formation, intervertebral space infection and cage aversion in both groups. Significant difference of relative disc space height was found in each group pre- and post- operatively (P lt; 0.01) and significant differences were evident between the two groups at any of the time points (P lt; 0.01). One month after operation, there was significant difference between the two groups (P lt; 0.05). There was also significant difference at the 3rd, 6th and 12th month after operation (P lt; 0.01). No sign offusion was found in each group at the 1st and 3rd month after operation. In bone-graft group, there were 7 vertebral fusion cases 6 months after operation and 23 vertebral fusion cases 12 months after operation. In cage group, there were 8 vertebral fusion cases 6 months after operation and 29 vertebral fusion cases 12 months after operation. There was no significant difference in the rate of fusion at 6 and 12 months follow-up between the two groups (P gt; 0.05). Significant difference of JOA scores was found in each group pre- and post- operatively (P lt; 0.05). And no significant difference in JOA scores at 1, 3, 6, and 12 months follow-up was evident between the two groups (P gt; 0.05). Conclusion There is no significant difference between the two groups in the fusion time, the fusion rate and the cl inical symptoms alleviation, indicating autologous il iac crest is appl icable to interbody fusion for the treatment of adult instabil ity of lower lumbar and good therapeutic effect can be achieved with no immunoreaction and lower cost.
ObjectiveTo explore the feasibility and effectiveness of unilateral pedicle screw rod and single poly (ether-ether-ketone) (PEEK) Cage for lumbar intervertebral disc protrusion. MethodsA total of 126 cases of single segment of lumbar intervertebral disc protrusion between January 2006 and June 2012 were divided into 2 groups in the randomized clinical trial. Unilateral pedicle screw fixation and single PEEK Cage was used in 63 cases (research group), and bilateral pedicle screw fixation and single PEEK Cage in 63 cases (control group). There was no significant difference in gender, age, disease duration, side, and affected segment between 2 groups (P>0.05). Schulte evaluation criterion was used to assess bone graft fusion, Oswestry disability index (ODI) to estimate the quality of life situation, and visual analogue scale (VAS) to evaluate the improvements of lower back pain. Macnab standards was applied to assess postoperative effectiveness, and Emery ways to measure the height of intervertebral space. ResultsThe incision length, operation time, intraoperative blood loss, hospitalization time, and hospitalization fee in research group were significantly less than those in control group (P<0.05). The patients were followed up 12-79 months (mean, 21.3 months) in research group, and 15-73 months (mean, 22.6 months) in control group. The postoperative lordosis was recovered well, and the height of intervertebral space was increased. No loosening or breakage of internal fixation occurred. The time of bone graft fusion was (6.8±1.3) months in research group and was (7.1±1.2) months in control group, showing no significant difference (t=1.153, P=0.110). The height of intervertebral space, ODI score, and VAS score were significantly improved when compared with preoperative ones in 2 groups (P<0.05), but no significant difference was found between 2 groups at preoperation and last follow-up (P>0.05). At 3 months after operation, postoperative effectiveness was assessed according to Macnab criterion, the excellent and good rate was 95.23% in research group (excellent in 13 cases, good in 47 cases, and fair in 3 cases) and was 71.42% in control group (excellent in 7 cases, good in 38 cases, fair in 15 cases, and poor in 3 cases); the research group was significantly superior to control group (χ2=6.110, P=0.006). ConclusionUnilateral pedicle screw fixation and single PEEK Cage has the advantages of small trauma, reliable fixation, shorter operation time, less bleeding, less economic cost, and early off-bed activity time. It can provide a simple and reliable choice in single segmental lumbar intervertebral disc protrusion.