ObjectiveTo explore the effectiveness of pedicle screw fixation combined with non-fusion technology for the treatment of thoracolumbar fracture (AO type A) through Wiltse paraspinal approach. MethodsBetween March 2011 and December 2012, 35 cases of thoracolumbar fractures were treated with pedicle screw fixation combined with non-fusion technology by Wiltse paraspinal approach. There were 27 males and 8 females, aged from 19 to 51 years (mean, 39.7 years). The time from injury to operation varied from 3 to 15 days (mean, 5.9 days). The causes of injury were traffic accident in 17 cases, falling from height in 11 cases, and crush trauma in 7 cases. All fractures were single-segment fracture, including T8 in 1 case, T9 in 2 cases, T10 in 2 cases, T11 in 3 cases, T12 in 12 cases, L1 in 10 cases, L2 in 4 cases, and L3 in 1 case. According to AO classification, there were 17 type A1 fractures (compression fracture), 3 type A2 fractures (splitting fracture), and 15 type A3 fractures (burst fracture). Based on American Spinal Injury Association (ASIA) spinal cord injury grade, all cases were in grade E before operation. Perioperative parameters were recorded; the anterior vertebral height and kyphotic Cobb angle of vertebral bodies were measured before and after operation to evaluate the effect of correction. ResultsThe mean operating time was 74 minutes; the mean blood loss was 125 mL; and the mean drainage volume was 51 mL. Skin necrosis of incision occurred in 2 cases and was cured after dressing change; primary healing of incision was obtained in the others. All patients were followed up 15-24 months (mean, 17.3 months). No loosening or breakage of internal fixation was found. The internal fixator was removed at 12-19 months after operation (mean, 15 months). There were significant differences in Cobb's angle and anterior vertebral body height between before operation and immediately after operation, before internal fixator removal as well as at last follow-up (P < 0.05). There was no significant difference in anterior vertebral body height among the postoperative time points (P > 0.05). There was significant difference in Cobb's angle between immediately after operation and before internal fixator removal as well as at last follow-up (P < 0.05), but the difference was not significant between before internal fixator removal and at last follow-up (P > 0.05). The motion of fixed segment was restored after internal fixator removal. ConclusionIt is an effective method of pedicle screw fixation combined with non-fusion technology through Wiltse paraspinal approach for the treatment of thoracolumbar fracture (AO type A). The method has the advantages of simple operation and less trauma. It can effectively rebuild the height of vertebral body and correct kyphotic deformity.
Objective To investigate the effect of the sequence of intermediate instrumentation with long screws and distraction-reduction on mild to moderate thoracolumbar fractures treated by posterior open and short-segmental fixation. MethodsThe clinical data of 68 patients with mild to moderate thoracolumbar burst fractures who met the selection criteria between January 2016 and June 2019 were retrospectively analyzed. The patients were divided into group ISDRF (intermediate screws then distraction-reduction fixation, 32 cases) and group DRISF (distraction-reduction then intermediate screws fixation, 36 cases) according to the different operation methods. There was no significant difference between the two groups in age, gender, body mass index, fracture segment, cause of injury, and preoperative load-sharing classification score, thoracolumbar injury classification and severity score, vertebral canal occupational rate, back pain visual analogue scale (VAS) score, anterior height of fractured vertebra, and Cobb angle (P>0.05). The operation time, intraoperative blood loss, complications, and fracture healing time were recorded and compared between the two groups. The vertebral canal occupational rate, anterior height of fractured vertebra, kyphosis Cobb angle, and back pain VAS score before and after operation were used to evaluate the effectiveness. Results There was no significant difference in intraoperative blood loss and operation time between the two groups (P>0.05). No vascular or spinal nerve injury and deep infections or skin infections occurred in both groups. At 1 week after operation, the vertebral canal occupational rate in the two groups was significantly improved when compared with that before operation (P<0.05), no significant difference was found in the difference of vertebral canal occupational rate before and after operation and improvement between the two groups (P>0.05). The patients in both groups were followed up 18-24 months, with an average of 22.3 months. All vertebral fractures reached bone union at 6 months postoperatively. At last follow-up, there was no internal fixation failures such as broken screws, broken rods or loose screws, but there were 2 cases of mild back pain in the ISDRF group. The intra-group comparison showed that the back pain VAS score, the anterior height of fractured vertebra, and the Cobb angle of the two groups were significantly improved at each time point postoperatively (P<0.05); the VAS scores at 12 months postoperatively and last follow-up were also improved when compared with that at 1 week postoperatively (P<0.05). At last follow-up, the anterior height of fractured vertebra in the ISDRF group was significantly lost when compared with that at 1 week and 12 months postoperatively (P<0.05), the Cobb angle had a significant loss when compared with that at 1 week postoperatively (P<0.05); the anterior height of fractured vertebra and Cobb angle in DRISF group were not significantly lost when compared with that at 1 week and 12 months postoperatively (P>0.05). The comparison between groups showed that there was no significant difference in the remission rate of VAS score between the two groups at 1 week postoperatively (P>0.05), the recovery value of the anterior height of fractured vertebra in ISDRF group was significantly higher than that in DRISF group (P<0.05), the loss rate at last follow-up was also significantly higher (P<0.05); the correction rate of Cobb angle in ISDRF group was significantly higher than that in DRISF group at 1 week postoperatively (P<0.05), but there was no significant difference in the loss rate of Cobb angle between the two groups at last follow-up (P>0.05). ConclusionIn the treatment of mild to moderate thoracolumbar burst fractures with posterior short-segment fixation, the instrumentation of long screws in the injured vertebrae does not affect the reduction of the fracture fragments in the spinal canal. DRISF can better maintain the restored anterior height of the fractured vertebra and reduce the loss of kyphosis Cobb angle during the follow-up, indicating a better long-term effectiveness.
ObjectiveTo summarize the experience in management of occult cerebrospinal fluid leakage (CSFL) in posterior thoracolumbar surgeries, and to explore the best drainage duration, as well as to analyse the ways to reduce the risk of CSFL. MethodsA retrospective analysis was made on the clinical data of 26 patients with occult CSFL in posterior thoracolumbar surgeries between January 2011 and January 2013. There were 15 males and 11 females, with the average age of 48.7 years (range, 36-59 years). Headache occurred in 19 cases, and 5 cases had nausea with 3 cases also having vomiting after operation. Drainage tube unobstructed and no CSFL from the skin incision were observed in 23 cases at the postoperative 2nd day, and the drainage pipe clamp test was performed at the 3rd day. Twenty-one patients had no CSFL and were given extubation; 2 cases having CSFL were given extubation after conservative treatments for 10 days. Three patients had CSFL with ineffective conservative treatments at the postoperative 2nd day, then received reoperation, incision suture, and drainage. At the postoperative 3rd day, if no CSFL was observed, these patients were given extubation and stayed in bed for 3-5 days. ResultsAll incisions healed and the healing time was 7-15 days (mean, 8 days). No incision infection, persistent CSFL, and other complications occurred. After extubation, headache, nausea, vomiting, and other symptoms were alleviated immediately. All patients were followed up 12-24 months (mean, 16 months). MRI at the postoperative 6th month showed no subcutaneous epidural pseudocyst. ConclusionThe quality of suturing is the key factor to prevent occult CSFL in posterior thoracolumbar surgery. Under the premise of good suture quality, extubation can be given at the postoperative 3rd day. Before extubation, the drainage pipe clamp test can be performed to make sure no CSFL and to reduce the risk of CSFL from the surgical incision after extubation.
In the present study, a finite element model of L4-5 lumbar motion segment was established based on the CT images and a combination with image processing software, and the analysis of lumbar biomechanical characteristics was conducted on the proposed model according to different cases of flexion, extension, lateral bending and axial rotation. Firstly, the CT images of lumbar segment L4 to L5 from a healthy volunteer were selected for a three dimensional model establishment which was consisted of cortical bone, cancellous bone, posterior structure, annulus, nucleus pulposus, cartilage endplate, ligament and facet joint. The biomechanical analysis was then conducted according to different cases of flexion, extension, lateral bending and axial rotation. The results showed that the established finite element model of L4-5 lumbar segment was realistic and effective. The axial displacement of the proposed model was 0.23, 0.47, 0.76 and 1.02 mm, respectively under the pressure of 500, 1 000, 1 500 and 2 000 N, which was similar to the previous studies in vitro experiments and finite element analysis of other people under the same condition. The stress distribution of the lumbar spine and intervertebral disc accorded with the biomechanical properties of the lumbar spine under various conditions. The established finite element model has been proved to be effective in simulating the biomechanical properties of lumbar spine, and therefore laid a good foundation for the research of the implants of biomechanical properties of lumbar spine.
ObjectiveTo compare the effectiveness of short segmental pedicle screw fixation with and without fusion in the treatment of thoracolumbar burst fracture. MethodsA retrospective analysis was made on the clinical data of 57 patients with single segment thoracolumbar burst fractures, who accorded with the inclusion criteria between February 2012 and February 2014. The patients underwent posterior short segmental pedicle screw fixation with fusion in 27 cases (fusion group) and without fusion in 30 cases (non-fusion group). There was no significant difference in gender, age, cause of injury, time between injury and admission, fracture segment and classification, and neurologic function America Spinal Injury Association (ASIA) classification between 2 groups, which had the comparability (P > 0.05). The operative time, blood loss, and hospitalization days were compared between 2 groups. The height of the injured vertebra, the kyphotic angle, and the range of motion (ROM) were measured on the X-ray film. The functional outcomes were evaluated by using the Greenough low-back outcome score and the visual analogue scale (VAS) for back pain. The neurologic functional recovery was assessed by ASIA grade. ResultsThe operative time was significantly shortened and the blood loss was significantly reduced in the non-fusion group when compared with the fusion group (P < 0.05), but no significant difference was found in hospitalization days between 2 groups (P > 0.05). The patients were followed up for 2.0-3.5 years (mean, 3.17 years) in the fusion group and for 2-4 years (mean, 3.23 years) in the non-fusion group. X-ray films showed that 2 cases failed bone graft fusion, the fusion time was 12-17 weeks (mean, 15.6 weeks) in the other 25 cases. Complication occurred in 2 cases of the fusion group (1 case of incision deep infection and 1 case of hematoma at iliac bone donor site) and in 1 case of the non-fusion group (fat liquefaction); primary healing of incision was obtained in the others. The Cobb angle, the height of injured vertebrae showed no significant difference between 2 groups at pre-operation, immediate after operation, and last follow-up (P > 0.05). The ROM of injured vertebrae showed no significant difference between 2 groups at 1 year after operation (before implants were removed) (P > 0.05). The implants were removed at 1 year after operation in all cases of the non-fusion group, and in 11 cases of the fusion group. At last follow-up, the ROM of injured vertebrae in the non-fusion group was significantly higher than that in the fusion group (P < 0.05), but no significant difference was found in Greenough low-back outcome score, VAS score, and ASIA grade between 2 groups (P > 0.05). ConclusionFusion is not necessary when thoracolumbar burst fracture is treated by posterior short segmental pedicle screw fixation, which can preserve regional segmental motion, shorten the operative time, decrease blood loss, and eliminate bone graft donor site complications.
Objective To investigate the effects of different puncture levels on bone cement distribution and effectiveness in bilateral percutaneous vertebroplasty for osteoporotic thoracolumbar compression fractures. Methods A clinical data of 274 patients with osteoporotic thoracolumbar compression fractures who met the selection criteria between December 2017 and December 2020 was retrospectively analyzed. All patients underwent bilateral percutaneous vertebroplasty. During operation, the final position of the puncture needle tip reached was observed by C-arm X-ray machine. And 118 cases of bilateral puncture needle tips were at the same level (group A); 156 cases of bilateral puncture needle tips were at different levels (group B), of which 87 cases were at the upper 1/3 layer and the lower 1/3 layer respectively (group B1), and 69 cases were at the adjacent levels (group B2). There was no significant difference in gender, age, fracture segment, degree of osteoporosis, disease duration, and preoperative visual analogue scale (VAS) score, and Oswestry disability index (ODI) between groups A and B and among groups A, B1, and B2 (P>0.05). The operation time, bone cement injection volume, postoperative VAS score, ODI, and bone cement distribution were compared among the groups. Results All operations were successfully completed without pulmonary embolism, needle tract infection, or nerve compression caused by bone cement leakage. There was no significant difference in operation time and bone cement injection volume between groups A and B or among groups A, B1, and B2 (P>0.05). All patients were followed up 3-32 months, with an average of 7.8 months. There was no significant difference in follow-up time between groups A and B and among groups A, B1, and B2 (P>0.05). At 3 days after operation and last follow-up, VAS score and ODI were significantly lower in group B than in group A (P<0.05), in groups B1 and B2 than in group A (P<0.05), and in group B1 than in group B2 (P<0.05). Imaging review showed that the distribution of bone cement in the coronal midline of injured vertebrae was significantly better in group B than in group A (P<0.05), in groups B1 and B2 than in group A (P<0.05), and in group B1 than in group B2 (P<0.05). In group A, 7 cases had postoperative vertebral collapse and 8 cases had other vertebral fractures. In group B, only 1 case had postoperative vertebral collapse during follow-up. ConclusionBilateral percutaneous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures can obtain good bone cement distribution and effectiveness when the puncture needle tips locate at different levels during operation. When the puncture needle tips locate at the upper 1/3 layer and the lower 1/3 layer of the vertebral body, respectively, the puncture sites are closer to the upper and lower endplates, and the injected bone cement is easier to connect with the upper and lower endplates.
Objective To explore the clinical effect of PSIS-A robot-assisted percutaneous screw in the treatment of thoracolumbar fracture. Methods Patients with thoracolumbar fracture who were hospitalized in Mianyang Orthopedic Hospital between August 2022 and January 2024 and required percutaneous pedicle screw f ixation were selected. Patients were divided into robot group and free hand group by random number table. Operative time, intraoperative bleeding, intraoperative radiation dose and time, implant accuracy rate, small joint invasion rate, Visual Analogue Scale score for pain and other indexes were compared between the two groups. Results A total of 60 patients were included. Among them, there were 28 cases in the robot group and 32 cases in the free hand group. On the third day after surgery, the Visual Analogue Scale score of the robot group was better than that of the free hand group (P=0.003). Except for intraoperative bleeding and radiation frequency (P>0.05), the surgical time, average nail implantation time, and intraoperative radiation dose in the robot group were all lower than those in the free hand group (P<0.05). The accuracy and excellence rate of nail planting in the robot group were higher than those in the free hand group (94.6% vs. 84.9%; χ2=7.806, P=0.005). There was no statistically significant difference in the acceptable accuracy rate (96.4% vs. 91.1%; χ2=3.240, P=0.072) and the incidence of screw facet joint invasion (7.2% vs.14.1%; χ2=3.608, P=0.058) between the two groups. Conclusion The application of PSIS-A type robot assisted percutaneous minimally invasive pedicle screw fixation in the treatment of thoracolumbar fr actures is promising.
OBJECTIVE: To study the changes of neural electrophysiology properties of cauda equina under double level compression and dynamic burdens, and to clarify the mechanisms of intermittent neurogenic claudication. METHODS: Thirty SD rats were divided into 5 groups (6 in each group). The laminectomy of L5 was performed in control group. In the experimental groups, the silicon sheets were inserted into the spinal canal of L4 and L6 to cause double level compression of cauda equina by 30%. Two hours after onset of compression, no dynamic burden was introduced in experimental group 1. Only high frequency stimulation(HFS) was introduced for 6 minutes in experimental group 2. Both HFS and additional increased compression were introduced for 6 minutes in experimental group 3. While only additional increased compression was introduced for 6 minutes in experimental group 4. After 6 minutes of dynamic burdens, all were returned to the status of static compression for another 30 minutes and then electrical examination was made. RESULTS: After 2 hours of compression, motor and sensory nerve conduction velocity (NCV) of all the four experimental groups decreased significantly (P lt; 0.05), but there was no significant difference between them. There was no significant change in the control group. There was no significant change of NCV in experimental group 1 during the last 30 minutes of experiment. NCV in the other three experimental groups decreased after introduction of dynamic burdens, especially in the experimental group 3. CONCLUSION: The above results showed that NCV of cauda equina decreased significantly under dynamic burdens during static compression. Two kinds of dynamic burdens introduced at the same time can cause more profound change than a single one.
ObjectiveTo evaluate the effectiveness of SRS-Schwab grade Ⅳ osteotomy combined with satellite rod for thoracolumbar old osteoporotic fracture with severe kyphosis.MethodsBetween April 2013 and August 2016, 20 cases of thoracolumbar old osteoporotic fracture with severe kyphosis were treated with SRS-Schwab grade Ⅳ osteotomy combined with satellite rod. All the patients were females, aged 49-71 years (mean, 54.8 years). The disease duration was 6-28 months with an average of 14 months. The T value of bone density was –4.4 to –1.8 (mean, –2.8). The preoperative Cobb angle was (43.0±11.3)°. The vertebral compression fracture segment was T12 in 9 cases, L1 in 8 cases, and L2 in 3 cases. Preoperative spinal cord function was evaluated by Frankel classification; there were 5 cases of grade D and 15 cases of grade E. The operation time, intraoperative blood loss, and perioperative complication were recorded. The Cobb angle for kyphosis and sagittal vertical axis (SVA) were recorded beforeoperation, at 3 months after operation, and at last follow-up. Oswestry disability index (ODI) was used to evaluate the effectiveness before operation and at last follow-up, and the evaluation indicators included pain degree, daily life self-care ability, extracting, walking, sitting, standing, sleeping, social activities, and traveling.ResultsThe operation time was 180-314 minutes (mean, 226 minutes). The intraoperative blood loss was 390-1 800 mL (mean, 750 mL). All the incisions healed by first intension without incision infection. Twenty patients were followed up 24-52 months, with an average of 30.9 months. During the follow-up period, no significant complication such as correction loss, nail breakage, rod breakage, pseudoarthrosis formation, or proximal and distal junctional kyphosis occurred. All patients were able to walk upright after operation, and the pain relieved significantly at 6 months after operation. Bone fusion achieved at 12 months after operation. The Frankel grade of nerve function improved from grade D to grade E at last follow-up in 5 patients with nerve damage before operation. At last follow-up, the indicator scores of ODI significantly improved when compared with preoperative values (P<0.05). Cobb angle significantly improved at 3 months after operation and at last follow-up (P<0.05) when compared with preoperative one, but there was no significant difference in the Cobb angles between 3 months after operation and last follow-up (P>0.05). There was no significant difference in SVA between pre- and post-operation (P>0.05).ConclusionSRS-Schwab grade Ⅳ osteotomy combined with satellite rod for thoracolumbar old osteoporotic fracture with severe kyphosis is effective in achieving satisfactory clinical outcomes, as well as maintaining correction of kyphosis.
Objective To investigate the effectiveness of Wiltse approach with fulcrum reduction technique and pedicle internal fixation in the treatment of AO-A type thoracolumbar fractures. Methods The clinical data of 16 patients with AO-A type thoracolumbar fractures treated with Wiltse approach with fulcrum reduction technique and pedicle internal fixation between September 2013 and January 2019 were retrospectively analyzed. There were 9 males and 7 females, the age ranged from 38 to 60 years, with an average age of 50.7 years. Causes of injury included 9 cases of falling from height, 3 cases of traffic accidents, 3 cases of falling, and 1 case crushed by heavy objects. Fractured segment involved T11 in 2 cases, T12 in 5 cases, L1 in 7 cases, and L2 in 2 cases. There were 6 cases of type A1, 3 cases of type A2, 5 cases of type A3, and 2 cases of type A4 according to AO fracture classification. The operation time, intraoperative blood loss, and removal time of internal fixator were recorded. Before operation, immediately after operation, before and after removal of internal fixator, the local kyphotic angle (LKA), anterior vertebral height (AVH), and posterior vertebral height (PVH) of fractured vertebral body were measured; visual analogue scale (VAS) score of back pain were evaluated before operation, at 3 days after operation, before and after removal of internal fixator. Results The operation time of the patients was 50-95 minutes, with an average of 70.7 minutes; the intraoperative blood loss was 50-230 mL, with an average of 132.9 mL; the internal fixator was removed after 18-30 months, with an average of 23.6 months. All patients were followed up 20-32 months, with an average of 25.6 months. No incision infection, hematoma, and other surgery-related complications, and internal fixator rupture residual complications occurred. All 16 patients achieved satisfactory reduction results. Immediate postoperative LKA, AVH, and PVH were significantly improved when compared with preoperative ones (P<0.05). There was a certain degree of reduction loss before internal fixator removal, and the difference in LKA was significant (P<0.05), but the difference in AVH and PVH were not significant (P>0.05). There was a certain degree of reduction loss after internal fixator removal, but only the difference in AVH was significant (P<0.05), and there was no significant difference in LKA and PVH (P>0.05). The VAS score of the back pain significantly improved at 3 days after operation and before internal fixator removal when compared with preoperative score (P<0.05). The pain after internal fixator removal was significantly worse than that before internal fixator removal (P<0.05). ConclusionThe Wiltse approach with fulcrum reduction technique and pedicle internal fixation in the treatment of AO-A thoracolumbar fractures has a short operation time, less intraoperative blood loss, and the posterior soft tissue and other structures are well protected during the operation. It can provide satisfactory clinical reduction results.