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 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.
Objective To explore and evaluate the accuracy and feasibil ity of individual rapid prototype (RP) drill templates for atlantoaxial pedicle screw implantation. Methods Volumetric CT scanning was performed in 8 adult cadaveric atlas and axis to collect Dicom format datas. Then three-dimensional (3D) images of atlas and axis were reconstructed and the parameters of pedicles of 3D model were measured by using software Mimics 10.01. The 3D model was saved by STLformat in Mimics. The scattered point cloud data of 3D model were processed and the 3D coordinate system was located in software Imageware 12.1. The curves and surfaces of 3D model were processed in software Geomagic Studio 10. The optimal trajectory of pedicle screw was designed and a template was constructed which accorded with the anatomical morphology of posterior arch of atlas and lamina of axis by using software Pro/Engineer 4.0. The optimal trajectory of pedicle screw and the template were integrated into a drill template finally. The drill template and physical models of atlas and axis were manufactured by RP (3D print technology). The accuracy of pilot holes of drill templates was assessed by visually inspecting and CT scanning. Results The individual drill template was used conveniently and each template could closely fit the anatomical morphology of posterior arch of atlas and lamina of axis. Template loosening and shifting were not found in the process of screw implantation. Thirty-two pedicle screws were inserted. Imaging and visual inspection revealed that the majority of trajectories did not penetrate the pedicle cortex, only 1 cortical penetration was judged as noncritical and did not injury the adjacent spinal cord, nerve roots, and vertebral arteries. The accuracy of atlas pedicle screw was grade 0 in 15 screws and grade I in 1 screw, and the accuracy of axis pedicle screw was grade 0 in 16 screws. Conclusion The potential of individual drill templates to aid implantation of atlantoaxial pedicle screw is promising because of its high accuracy.
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 systematically review the efficacy of at the fracture level (AFL) versus cross the fracture level (CFL) short-segment pedicle screw fixation for thoracolumbar fractures. MethodsWe electronically search PubMed, The Cochrane Library (Issue 8, 2015), EMbase, CBM, CNKI, VIP and WanFang data to collect randomized controlled trials (RCTs) of AFL versus CFL short segment pedicle screw fixation for thoracolumbar fractures from inception to Aug. 2015. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was performed using RevMan 5.3 software. ResultsA total of 11 RCTs involving 730 patients were included. The results of meta-analysis indicated that: compared with the CFL group, the AFL group had more blood loss (MD=9.8, 95%CI 7.40 to 12.20), less implant failure rate (RR=0.19, 95%CI 0.07 to 0.48), lower long term postoperative VAS score of thoracolumbar pain (MD=-1.20, 95%CI -1.85 to -0.56), higher correction in short term postoperative kyphotic Cobb angle (MD=3.56, 95%CI 2.25 to 4.87), smaller value in long term postoperative kyphotic Cobb angle and its loss of correction (MD=-3.95, 95%CI -7.78 to -0.12; MD=-4.65, 95%CI -6.91 to -2.40), smaller degree of anterior vertebral height compression in short and long term postoperative (MD=-3.51, 95%CI -5.23 to -1.80; MD=-8.28, 95%CI -12.22 to -4.33), better result in long term postoperative anterior vertebral height and its loss of correction (MD=8.00, 95%CI 3.85 to 12.15; MD=-6.06, 95%CI -7.68 to -4.44). There were no significant differences between two groups regarding operation time, infectious complications and short term postoperative kyphotic Cobb angle (MD=0.11, 95%CI -5.36 to 5.57; RR=0.55, 95%CI 0.11 to 2.85; MD=-0.66, 95%CI -2.19 to 0.87). ConclusionCurrent evidence shows that AFL short-segment pedicle screw fixation for thoracolumbar fractures is superior to CFL fixation. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.
To investigate the shortsegment pedicle screw in treating degenerative L4 spondylolisthesis and the relationship of the preliminarily bending degree of the titanium rod with the lumbar lordosisangle, the slipping angle and the slipping percentage and to evaluate the clinical coincidence and curative effects of the preliminarilybent rod. MethodsFrom September 2005 to March 2007, 31 female patients (age, 40-70 years; average, 58.3 years) were admitted for surgical treatment of their L4 degenerative spondylolisthesis (MeyerdingⅠ°, Ⅱ°)． Their lumbar lordosis angle （x1）, slipping angle (x2), and slipping percentage (x3) were measured in the L4,5 segment before operation. During the operation, the titanium rod bent beforehand according to the corresponding standards was inserted. The angle of the bent rod (Y) was measured, and then the multiple linear regression equation was established. The regression equation was applied to the surgical treatment of the 30 patients.Results According to the criteria in the JOA scoring system, the 31 patients had scores of 8.300± 1.080 and 26.916±1.859 before operation and after operation, respectively. There was a significant difference between before operation and after operation（Plt;0.05）. The established multiple linear regression equation was as follows:Y=0.1390-0.327logx1+0.463x2+0.288x32．The operating time was 51.290±3.408 min in the 30 patients who underwent an insertion of the preliminarilybent rod during the operation; however, the operating time was 102.360±5.004 min in the 31 patients who underwent an insertion of the bent rod that was made based on experience during the previous operations. There was a significant difference in the operating time between the two kinds of the rods （Plt;0.05）. Estimated according to 90%, 95% and 99% of the areas under the normalcurve, the clinical coincidence rates in the preliminarily bending degrees of the titanium rod in the 30 patients were 80.00％，90.00％ and 96.67％, respectively.Conclusion The titanium rod that has been bent into a certain angle before operation according to the established criteria can definitely diminish its strain during operation and efficiently shorten the operating time．Thiskind of the titanium rod has a good coincidence in clinical application and can be effectively used in clinical practice.It is worth reference during the clinical operation.
【Abstract】 Objective To study the effectiveness of computer assisted pedicle screw insertion in osteoporotic spinalposterior fixation. Methods Between December 2009 and March 2011, 51 patients underwent pedicle screw fixation using the computer assisted navigation (navigation group), while 41 patients underwent the conventional technique (traditional group). All patients had osteoporosis under the dual-energy X-rays absorptiometry. There was no significant difference in age, gender, bone mineral density, involved segment, preoperative complications, and other general status between 2 groups (P gt; 0.05). The amount of blood loss, the operation time, the rate of the pedicle screw re-insertion, and the postoperative complication were observed. The state of the pedicle screw location was assessed by CT postoperatively with the Richter’s classification and the fusion state of the bone graft was observed using three-dimensional (3-D) CT scans during follow-up. Results A total of 250 screws were inserted in navigation group, and 239 were inserted successfully at first time while the other 11 screws (4.4%) were re-inserted. A total of 213 screws were inserted in traditional group, and 190 were successful at first time while 23 screws (10.8%) were re-inserted. There was significant difference in the rate of screws re-insertion between 2 groups (χ2=6.919, P=0.009). Both the amount of blood loss and the operation time in navigation group were significantly less than those in traditional group (P lt; 0.05). According to Richter’s classification for screw location, the results were excellent in 240 screws, good in 10 screws innavigation group; the results were excellent in 191 screws, good in 21 screws, and poor in 1 screw in traditional group. Significant difference was noticed in the screw position between 2 groups (χ2=7.566, P=0.023). The patients were followed up (7.8 ± 1.5) months in navigation group and (8.7 ± 1.5) months in traditional group. No loosening, extraction, and breakage of the pedicle screw occurred in navigation group, and all these patients had successful fusion within 6 months postoperatively. While in traditional group, successful fusion was shown in the other patients by 3-D CT, except the absorption of bone graft was found in only 1 patient at 6 months after operation. And then, after braking by adequate brace and enhancing the anti-osteoporotic therapy, the bone graft fused at 9 months postoperatively. Conclusion The computer assisted navigating pedicle screw insertion could effective reduce the deviation or re-insertion of the screws, insuring the maximum stabil ity of each screw, mean while it can reduce the exposure time and blood loss, avoiding complication. The computer assisted navigation would be a useful technique which made the pedicle screw fixation more safe and stable in patients with osteoporosis.
ObjectiveTo explore the feasibility of the clinical application of individualized simulated S1 pedicle screw.MethodsThe data of patients with lumbar disease diagnosed and treated in the Fourth People’s Hospital of Zigong from May 2017 to April 2019 were retrospectively analyzed. According to the preoperative individualized design of the S1 pedicle screw placement path, the patients were divided into individualized screw placement group and traditional screw placement group. The distance D between the screw tip and the endplate of the S1, the angle α of the screw in the plane of the dysplasia and the lumbar pedicle of the L5, the angle of oblique angle β, the number of screws of 35 and 40 mm in length, and the screw loosening rate (followed-up within 1 year) in the two groups were analyzed.ResultsA total of 59 patients were enrolled in this study, 31 in the individualized screw placement group and 28 in the traditional screw placement group. The differences in the distance D between the screw tip and the endplate of the S1 [(2.61±0.82) vs.(4.13±1.51) mm; t=-5.718, P<0.001], the angle α of the screw in the plane of the dysplasia and the lumbar pedicle of the L5 [(9.31±3.52) vs. (13.53±4.78)°; t=-5.646, P<0.001], the angle of oblique angle β [(15.73±6.04) vs. (10.65±5.09)°; t=3.022, P=0.004], the proportion of using screw models [40 mm in length: 56 vs. 8; 35 mm in length: 6 vs. 48; χ2=68.539, P<0.001], and the screw loosening rate followed-up within 1 year [3.22% vs. 16.07%; χ2=5.774, P<0.001] were statistically significant between the individualized screw placement group and the traditional screw placement group.ConclusionsPreoperative individualized design of the pedicle screw of the S1 pedicle screw can be used in clinical practice. The biomechanical stability of the S1 pedicle screw can be improved and the sagittal balance can be achieved.
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 investigate the effectiveness of debridement and single-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation and autograft bone fusion in treatment of thoracolumbar tuberculosis. MethodsBetween January 2008 and October 2010, 22 patients with thoracolumbar tuberculosis were treated by debridement and single-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation and autograft bone fusion, and were given anti-tuberculosis therapy after operation. Of 22 patients, 14 were male and 8 were female with an average age of 42 years (range, 18-66 years). The disease duration was 2-16 months (mean, 6 months). Sixteen double-segment lesions included T7, 8 in 3 cases, T8, 9 in 1 case, T9, 10 in 3 cases, T11, 12 in 2 cases, L1, 2 in 4 cases, and L3, 4 in 3 cases; 6 three-segment lesions included T7-9 in 2 cases, T11-L1 in 1 case, and L2-4 in 3 cases. Preoperative visual analogue scale (VAS) score was 7.50 ± 0.63. According to Frankel classification of America Spinal Injury Association (ASIA), 2 cases were rated as grade B, 4 cases as grade C, 9 cases as grade D, and 7 cases as grade E. ResultsTwenty-two patients were followed up 15-36 months (mean, 25.2 months). Wound infection occurred in 1 case and was cured after corresponding treatment; incision healed by first intention in other patients. No loosening or breakage of internal fixator was found; the patients had no deteriorations in spinal cord injury or cerebrospinal fluid leakage. X-ray films and CT showed obvious bone fusion in the intervertebral space. The time of bone fusion was 3-6 months (mean, 5.2 months). The erythrocyte sedimentation rate after operation was significantly lower than that before operation (P lt; 0.05). The VAS scores were significantly improved to 2.90 ± 1.00 at 2 weeks after operation and 2.60 ± 0.81 at last follow-up (P lt; 0.05). At last follow-up, nerve function was significantly improved. According to Frankel classification, 2 cases were rated as grade C, 5 cases as grade D, and 15 cases as grade E. ConclusionSingle-incision vertebral screw-rod fixation combined with pedicle screw-rod fixation for thoracolumbar tuberculosis is a stable and minimally invasive method. However, the long-term effectiveness need further follow-up.