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 study the development, investigation, and application of the artificial vertebral body so as to provide an essential reference for the future research and clinical application. Methods The recent articles on materials, types, and clinical applications of the artificial vertebral body were reviewed.Results The materials used for the artificial vertebral body were porcelain, alloy, variant bone, and composite. But each of them had its own advantages and disadvantages. The types of the artificial vertebral body were grouped as expandable and non-expandable ones; however, the expandable type was much better. The artificial vertebral body had been applied to the treatments of spinal tumor, tuberculosis, fracture, and infection, with better effects. Conclusion The artificial vertebral body can beextensively applied. However, the materials and types need to be improved.
Objective To review the progress of surgical treatment for the thoracolumbar spinal tuberculosis. Methods The related literature of surgical treatment for the thoracolumbar spinal tuberculosis was reviewed and analyzed from the aspects such as surgical approach, fixed segments, fusion ranges, bone graft, and bone graft material research progress. Results Most scholars prefer anterior or combined posterior approach for surgical treatment of thoracic and lumbar tuberculosis because it possessed advantage of precise effectiveness. In recent years, a simple posterior surgery achieved satisfactory effectiveness. The fixation segments are mainly composed of short segments or intervertebral fixation. The interbody fusion is better for the bone graft fusion range and manner, and the bone graft materials is most satisfied with autologous iliac Cage or titanium Cage filled with autologous cancellous bone. Conclusion The perfect strategy for treating the thoracolumbar spinal tuberculosis has not yet been developed, and the personalized therapy for different patients warrants further study.
Objective To study the clinical effects of the artificial vertebral body of the biomimetic nanohydroxyapatite/polyamide 66 (nHA/PA66) compositefor the structural reconstruction and the height restoring of the vertebral body in the thoracolumbar fractures by the anterior surgical procedures. Methods From December 2003 to January 2006, 42 patients with thoracolumbar fractures received the anterior surgical procedures to decompress and reconstruct the spinal vertebral structure with the artificial vertebral body of the nHA/PA66 composite. Among the patients, there were 28 males and 14 females, aged 1767 years, averaged 43.6 years. The thoracolumbar fractures developed at T12 in 5 patients, at L1 in 17, at L2 in 14, and at L3 in 6. The height of the anterior border of thevertebral body amounted to 29%-47% of the vertebral body height, averaged 40.6%.The Cobb angle on the sagittal plane was 2138° averaged 27.6°. According tothe Frankel grading scale, the injuries to the nerves were as the following: Grade A in 7 patients, Grade B in 19, Grade C in 8, Grade D in 6, and Grade E in 2. Results All the 42 patients were followed up for 625 months. Among the patients, 36 were reconstructed almost based on the normal anatomic structure, and 6 were well reconstructed. The mean height of the anterior border of the vertebralbody was 40.6% of the vertebral body height before operation but 91.7% after operation. And the reconstructed height of the vertebra was maintained. The mean Cobb angle on the sagittal plane was 27.6°before operation but 13.4° after operation. All the patients had a recovery of the neurological function that had a 1grade or 2grade improvement except 7 patients who were still in Grade A and 2 patients who were in Grade D. The implant was fused 35 months after operation. No infection, nail break, bar/plate break or loosening of the internal fixation occurred. Conclusion The artificial vertebral body of the biomimetic nHA/PA66 composite can effectively restore the height and the structure of the vertebra, can be fused with the vertebral body to reconstruct the spinal structural stability effectively, and can be extensively used in the clinical practice.
To analyze the effectiveness of posterior pedicle screw system combined with interbodyfusion in treating lumbar spondylol isthesis. Methods Between January 2005 and January 2009, 26 patients with lumbar spondylol isthesis underwent posterior pedicle screw system combined with interbody fusion, including 11 males and 15 females with an average age of 56.8 years (range, 36-73 years). The disease duration was 7 months to 11 years. The affected lumbars were L3 in 3 cases, L4 in 12 cases, and L5 in 11 cases. According to the Meyerding evaluating system, 21 cases were classified as degree III, 5 cases as degree III-IV, and 1 case as degree IV. The cl inical results were investigated by measuring radiographic measurements, including Taillard index, Boxall index, sl i pping angle, lumbar lordosis angle,and intervertebral height index preoperatively, immediately, 2 weeks and 3 months postoperatively, respectively. SUK’s criteria was used to judge bone graft fusion. Results Primary heal ing of the incisions was achieved in all cases. Allpatients were followed up 25.8 months on average (range, 10-51 months). There were significant differences in Taillardindex, Boxall index, sl i pping angle, lumbar lordosis angle, and intervertebral height index between preoperatively andimmediately, 2 weeks, 3 months after operation (P lt; 0.05). Bone graft fusion was achieved at 3-8 months after operation(mean, 3.5 months); and the fusion rate was 100%. According to Japanese Orthopedic Association (JOA) scoring, theresults were excellent in 17 cases, good in 7 cases, fair in 1 case, and poor in 1 case; and the excellent and good rate was 92.3%. Compl ications occurred in 2 cases, including nail or rod breakage and nerve injury, and they were cured aftertreatment. Conclusion Posterior pedicle screw system combined with interbody fusion treating lumbar vertebralspondylol isthesis can afford sol id internal fixation and achieve a satisfactory reduction, so it maybe an ideal procedure and a worthy recommended method for treating lumbar spondylol isthesis.
Objective To research the transfer of adenovirus human bone morphogenetic protein 4 (Ad-hBMP-4) to human degenerative lumbar intervertebral disc cells in vitro and analyze its effect on the proteoglycan, collagen type II, and Sox9 of intervertebral disc cells. Methods Identified Ad-hBMP-4 was amplified and detected. Degenerative lumbar intervertebral disc cells were aspirated from the degenerative lumbar intervertebral disc of patients with Modic III level disc protrusion (aged, 27-50 years). The expressing position of collagen type II was identified in the intervertebral disc cells through the laser confocal microscope. The intervertebral disc cells at passage 1 were transfected with Ad-hBMP-4 as experimental group. After 3 and 6 days of transfection, RT-PCR was used to detect the mRNA expressions of proteoglycan, collagen type II, and Sox9, and Western blot to detect the expressions of proteoglycan and collagen type II proteins. Non-transfected cells at passage 1 served as control group. Results The virus titer of Ad-hBMP-4 was 5 × 106 PFU/mL. No morphological changes in the cells after transfection by Ad-hBMP-4. Collagen type II mainly expressed in the cell cytoplasm. The mRNA expressions of the proteoglycan, collagen type II, and Sox9 in experimental group at 3 and 6 days after transfection were significantly higher than those in control group by RT-PCR (P lt; 0.05), and the expressions of proteoglycan and collagen type II proteins were significantly higher than those in contorl group by Western blot (P lt; 0.05). There were significant differences between 3 days and 6 days in experimental group (P lt; 0.05). Conclusion Ad-hBMP-4 could transfect human degenerative lumbar intervertebral cells with high efficiency and promote collagen type II, proteoglycan, and Sox9 expressions. hBMP-4 may play an important role in the repair process during early disc degeneration.
Objective To investigate if the course of intervertebral disc degeneration (IDD) is delayed by injecting lentivirus (Lv) vector carrying bone morphogenetic protein 2 (BMP-2) and inhibitor of differentiation 1 (Id1) genes directly into the nucleus pulposus. Methods Thirty-two New Zealand white rabbits, 2.0-2.5 kg in weight and 4 months in age, were used to establish the IDD models at L3, 4, L4, 5, and L5, 6 discs with annular puncture via transabdominal approach. Thirty rabbits with successful modeling were randomly divided into 5 groups, 6 rabbits every group. At 4 weeks after modeling, rabbits were injected with Lv-BMP-2 (group A), with Lv-BMP-2 and Lv-Id1 (group B), with Lv-Id1 (group C), with Lv-green fluorescent protein (group D), and with PBS (group E). At 2, 4, and 8 weeks after injection, T2-mapping MRI was performed on 2 rabbits each group to obtain the T2 values, and then subsequently the lumbar disc tissues were harvested to test the mRNA expressions and contents of collagen type II and proteoglycan by real-time fluorescent quantitative PCR and ELISA methods. Results T2-mapping MRI demonstrated that there was no significant difference in the T2 value between different groups at immediate and 2 weeks after injection (P>0.05). The T2 value of groups A and B was significantly higher than that of groups C, D, and E at 4 weeks after injection (P<0.05), but no significant difference was observed between group A and group B (P>0.05). The T2 value of group B was significantly higher than that of the other groups at 8 weeks after injection (P<0.05). The real-time fluorescent quantitative PCR and ELISA showed that the expressions and contents of collagen type II and proteoglycan in group B were significantly higher than those in the other groups at 2, 4, and 8 weeks after injection (P<0.05). Conclusion Combined application of Lv-BMP-2 and Lv-Id1 can delay IDD changes in rabbit IDD models.
Objective To make a mouse model of traumatic spinal cord injury (SCI) by Allen’s weight dropping (WD),which might be helpful for further research on the mechanism of SCI. Methods A total of 180 healthy female mice, weighing 17 - 23 g (20 g on average), were randomized into 4 groups (n=45 per group): the experimental groups of A, B and C and the control group of D. Experimental groups were distinguished by the amount of weight or the height from which the weight was dropped onto an impounder resting on the dura (2.0 × 2.5 g·cm, 2.5 × 3.0 g·cm, 3.0 × 5.0 g·cm). In group D, neural scute was opened only and spinal cord was exposed without SCI. The recovery of the lower extremity was observed at various time points (0,6 and 12 hours, 1 and 3 days, 1, 2, 4 and 8 weeks) by using the Basso mouse scale (BMS) scoring system, motor evoked potentials (MEP) and histological observation. Results MEP displayed that the incubation period of N1 wave was extended in group B after 6 hours and in group C after 12 hours. As time passed by, the incubation periods of N1 wave in group A, group B and group C began to shorten. The incubation period in group A was close to normal at 4 weeks (2.40 ± 0.12) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group B was close to normal at 8 weeks (2.96 ± 0.15) ms, and there was no significant difference compared with group D (P gt; 0.05). The incubation period in group C was still relatively high at 8 weeks (3.76 ± 0.13) ms, and there was a significant difference compared with group D (P﹤0.05). Both hind l imbs of all mice were paralytic instantly after SCI, the score of main BMS was 0 point; the score of main BMS was close to 0 at the first 3 days after SCI, the score of main BMS of group A was 8.00 ± 0.13 and group B was 7.50 ± 0.31 at 8 weeks;the score of main BMS of group A was 5.45 ± 0.12 at 1 week and group B was 5.45 ± 0.15 at 2 weeks which were significant difference compared with group D (P﹤0.05).There were significant differences among groups A, B and C after 1 week of SCI (P lt; 0.05), and group C was lower than the others(P﹤0.01). The score of adjuvant BMS of group A was 10.12 ± 0.76 at 2 weeks and group B was 9.85 ± 0.55 at 8 weeks which was no significant difference compared with the group D at the same time (P gt; 0.05). Histological observation showed hemorrhage, cellular edema, inflammatory cell infiltration, nerve cell swell and solution of Nissl body 12 hours after SCI in group C. As time passed by, the number of nerve cells decreased, the gl ial cell prol iferated and Nissl body vanished. There was much gl ial cell prol iferation and cavitation 2 weeks after SCI in group C. The nerve cell decrease and cavitation in group B was sl ighter than that in group C, and group A was the sl ightest. In group D, there was no obvious change of the number of cells during the observation apart from sl ight edema in early period. Conclusion The mouse model precisely reflects the pathological and physiological features and law of change after different degrees of SCI, and can be used as a standard of mouse model of traumatic SCI by Allen’s WD.
Objective To investigate the effectiveness of transvertebral space and under the pedicle osteotomy for thoracolumbar kyphosis caused by old osteoporotic vertebral compression fracture (OVCF). Methods The clinical data of 11 patients with thoracolumbar kyphosis caused by old OVCF treated by transvertebral space and under the pedicle osteotomy between January 2016 and December 2020 were retrospectively analyzed. There were 2 males and 9 females, with an average age of 61.3 years (range, 50-77 years) and with a median disease duration of 8 years (range, 6 months to 50 years). Fracture reasons: 9 cases had a clear history of trauma, and 2 cases had no obvious incentive. A total of 11 vertebrae was involved in fracture, including T12 in 3, L1 in 7, L2 in 1. The operation time, intraoperative blood loss, postoperative drainage volume, and complications were recorded. Full-length X-ray films of spine and local X-ray films of the operation area were examined before operation, at 7 days after operation, and at last follow-up. The Cobb angle of thoracolumbar kyphosis was measured, and the correction rate was calculated. The visual analogue scale (VAS) score and Oswestry disability index (ODI) were recorded to assess patients’ pain and functional improvement before operation, at 1 month after operation, and at last follow-up. Results All operations were successfully completed. The average operation time was 188.6 minutes (range, 140-215 minutes); the average intraoperative blood loss was 268.2 mL (range, 100-500 mL); the average postoperative drainage volume was 615.5 mL (range, 160-1 500 mL). One patient developed bilateral thigh rebound pain after operation, which relieved after symptomatic treatment of nutritional nerve and acesodyne. All patients were followed up 14.7 months on average (range, 6-56 months). At last follow-up, osseous fusion was observed in all patients, and no fracture, loose, or displacement of internal fixator was observed on imaging. At 7 days after operation and at last follow-up, the Cobb angle of thoracolumbar kyphosis significantly improved when compared with preoperative one (P<0.05), and there was no significant difference between at 7 days after operation and at last follow-up (P>0.05); the correction rates of Cobb angle at 7 days after operation and at last follow-up were 68.0%±9.8% and 60.3%±11.9%, respectively. At 1 month after operation and at last follow-up, the VAS score and ODI significantly improved when compared with preoperative ones, and further improved at last follow-up when compared with those at 1 month after operation, all showing significant differences (P<0.05). ConclusionTransvertebral space and under the pedicle osteotomy is an effective way to treat thoracolumbar kyphosis caused by old OVCF with less trauma, shorter operation time, and less intraoperative blood loss. Patients can obtain good orthopedic results and quality of life.
Objective To explore the effectiveness and related issues in the treatment of multiple segments of thoracolumbar tuberculosis through posterior unilateral debridement with bone graft and internal fixation. Methods The clinical data of 29 patients with multiple segments of thoracolumbar tuberculosis who met the selection criteria were retrospective analyzed between January 2012 and July 2015. There were 17 males and 12 females, with age of 21-62 years (mean, 37.4 years). Lesions contained 3-8 vertebral segments, including 3 segments in 6 cases, 4-6 segments in 17 cases, and 7-8 segments in 6 cases. The center lesions located at thoracic spine in 8 cases, lumbar spine in 10 cases, and thoracolumbar segment in 6 cases, and thoracic lumbar skip lesions in 5 cases. The complications included vertebral abscess in 7 cases, psoas major abscess in 6 cases, sacral spine muscle abscess in 7 cases, iliac fossa and the buttocks abscess in 1 case, spinal canal abscess in 2 cases. Preoperative neurological function was assessed according to the American Spinal Injury Association (ASIA) classification: 1 case of grade B, 3 cases of grade C, 8 cases of grade D, and 17 cases of grade E. The disease duration was 6-48 months (mean, 19.3 months). All the patients were treated with posterior unilateral transpedicular or transarticular debridement with bone graft fusion and internal fixation under general anesthesia. Pre- and post-operative visual analogue scale (VAS) score, Oswestry disability index (ODI), and sagittal Cobb angle were recorded and compared. Bridwell classification standard was used to evaluate bone graft fusion. According to the number and the center of the lesion, the necessity to placement of titanium mesh cage was analyzed. Results All the patients were followed up 18-30 months (mean, 24 months). Cerebrospinal fluid leakage occurred in 3 cases, intercostal neuralgia in 2 cases, wound unhealed and fistula formation in 1 case, and ofiliac fossa abscess recurred in 1 case, and all recovered after symptomatic treatment. During follow-up, no fracture or loosing of internal fixation was found and all the lesions were cured at last follow-up. According to Bridwell classification standard, bone graft achieved bony fusion during 4-9 months after operation. The VAS score, ODI, and Cobb angle at immediate after operation and at last follow-up were significantly improved when compared with preoperative ones (P<0.05). At last follow-up, the neural function of all patients improved significantly when compared with preoperative one (Z= –3.101, P=0.002). The ratio of no placement of titanium mesh cage was significantly higher in patients with more than 6 lesion segments (6/6, 100%) than in patients with less than 6 lesion segments (4/23, 17.4%) (χ2=14.374, P=0.000). And the ratio of placement of titanium mesh cage was not significantly different between the patients with the different locations of center focus (χ2=0.294, P=0.863). Conclusion For treating multiple segments of thoracolumbar tuberculosis, the method of posterior unilateral debridement with bone graft and internal fixation can decrease the damage of posterior spinal structures and surgical trauma.