Objective To investigate the amount of bone grafting, bone defect gap residual rates, and biomechanical stability of the injured vertebral body after reduction of thoracolumbar burst fractures, pedicle screw-rods fixation, and bone graft by bilateral pedicle or unilateral spinal canal. Methods Eighteen fresh lumbar spine (L1-5) specimens of calves (aged 4-6 months) were collected to establish the burst fracture model at L3 and divided into 3 groups randomly. After reduction and fixation with pedicle screws, no bone graft was given in group A (n=6), and bone graft was performed by bilateral pedicles in group B (n=6) and by unilateral spinal canal in group C (n=6). The amount of bone grafting in groups B and C was recorded. The general situation of bone defect gaps was observed by the DR films and CT scanning, and the defect gap residual rates of the injured vertebrae were calculated with counting of grids. The compression stiffness was measured by ElectreForce-3510 high precision biological material testing machines. Results The amount of bone grafting was (4.58 ± 0.66) g and (5.72 ± 0.78) g in groups B and C respectively, showing signficant difference (t=2.707, P=0.022). DR films and CT scanning observation showed large bone defect gap was seen in injured vertebrae specimens of group A; however, the grafting bone grains was seen in the “eggshell” gap of the injured vertebral body, which were mainly located in the posterior part of the vertebral body, but insufficient filling of bone graft in the anterior part of the vertebral body in group B; better filling of the grafting bone grains was seen in injured vertebral body of group C, with uniform distribution. The bone defect gap residual rates were 52.0% ± 5.5%, 39.7% ± 2.5%, and 19.5% ± 2.5% respectively in groups A, B, and C; group C was significantly lower than groups A and B (P lt; 0.05), and group B was significantly lower than group A (P lt; 0.05). Flexion compressive stiffness of group C was significantly higher than that of groups A and B (P lt; 0.05), but no significant difference was found between groups A and B (P gt; 0.05). Extension compressive stiffness in group C was significantly higher than that in group A (P lt; 0.05), but no significant difference was found between groups A and B, and between groups B and C (P gt; 0.05). The compression stiffness of left bending and right bending had no significant difference among 3 groups (P gt; 0.05). Conclusion Thoracolumbar burst fracture pedicle screws fixation with bone grafting by unilateral spinal canal can implant more bone grains, has smaller bone defect gap residual rate, and better recovery of flexion compression stiffness than by bilateral pedicles.
Objective To discuss the improved method and effectiveness of posterior pedicle-screw fixation combined with restoring and grafting through the injured vertebrae for treating thoracolumbar burst fracture. Methods Between March 2008 and September 2010, 21 patients with thoracolumbar burst fracture were treated by posterior pedicle-screw fixationcombined with restoring and grafting through the injured vertebrae. Of 21 cases, 15 were male and 6 were female with an age range of 20-61 years (mean, 38.4 years). Affected segments included T12 in 5 cases, L1 in 7 cases, L2 in 5 cases, and T12-L1 in 4 cases. According to Frankel classification for neurological function, 2 cases were rated as grade A, 4 cases as grade B, 6 cases as grade C, 5 cases as grade D, and 4 cases as grade E; based on Denis classification, all 21 cases were burst fractures, including 7 cases of type A, 11 cases of type B, and 3 cases of type C. The X-ray film was taken to measure the relative height of fractured vertebrae and Cobb’s angle, and the function of the spinal cord was evaluated at preoperation, postoperation, and last followup. Results All the incisions healed primarily. The 21 patients were followed up 12-30 months (mean, 26 months). No loosening or breakage of screws and rods occurred. X-ray films showed good bone heal ing with the heal ing time from 12 to 23 months (mean, 16 months). The Cobb’s angles at 1 week and 1 year postoperatively were (3.4 ± 2.4)° and (5.2 ± 3.2)° respectively, showing significant differences when compared with preoperative angle (22.1 ± 1.2)° (P lt; 0.05), while no significant difference between 1 week and 1 year after operation (P gt; 0.05). The anterior height of injured vertebrae recovered from (14.6 ± 2.1) mm (40.2% ± 1.5% of the normal) at preoperation to (36.0 ± 2.0) mm (95.3% ± 1.3% of the normal) at 1 week, and to (35.0 ± 2.4) mm (94.4% ± 2.5% of the normal) at 1 year; significant differences were found between preoperation and postoperation (P lt; 0.05), while no significant difference between 1 week and 1 year after operation (P gt; 0.05). At 1 year after operation, the Frankel neurological function grade was improved in varying degrees, showing significant difference when compared with preoperative grade (χ2=11.140, P=0.025). Conclusion Improved method of posterior pedicle-screw fixation combined with restoring and grafting through the injured vertebrae in treatment of thoracolumbar burst fracture can reconstructthe anterior and middle column stabil ity and prevent loss of Cobb’s angle and height of vertebrae.
Objective To evaluate the early cl inical outcomes of subtotal corpectomy and intervertebral bonegrafting through posterior approach alone in the treatment of thoracolumbar burst fracture or thoracolumbar fracturedislocation.Methods Between January 2009 and December 2010, 20 patients with thoracolumbar burst fracture orthoracolumbar fracture dislocation were treated with subtotal corpectomy and intervertebral bone grafting through posteriorapproach alone. There were 14 males and 6 females, with an average age of 36.1 years (range, 19-47 years). Fractures were causedby falling from height in 12 cases, traffic accident in 6 cases, and crushing in 2 cases. According to AO classification, there were10 cases of A3 type, 8 cases of B2 type, and 2 cases of C2 type. Single segment was involved in 8 cases, double segments in 12cases. Twelve cases complicated by fracture dislocation and 6 cases by lateral displacement. All patients had bones occupancyin vertebral canal. The preoperative Cobb angle was (30.2 ± 3.9)°. According to Frankel classification for neurological function,there were 4 cases of grade B, 9 cases of grade C, and 7 cases of grade D at preoperation. The mean time between injury andoperation was 4.5 days (range, 1-12 days). Results All incisions healed by first intention, and no infection occurred.Twenty patients were followed up 8-16 months (mean, 12 months). The interbody fusion time was 6-9 months (mean, 7months). Neurological function recovered 1 to 3 grades: 1 case of grade C, 2 cases of grade D, 17 cases of grade E at last followup.The Cobb angle was (6.5 ± 4.2)° at last follow-up, showing significant difference when compared with preoperative value(t=2.39, P=0.00). No breaking or loosening of screw and implant sinkage occurred. Conclusion A combination of subtotalcorpectomy and intervertebral bone grafting through posterior approach alone has the advantages of complete decompression,restoration of spinal stabil ity, restoration of vertebral body height, high bone healing rate, and good recovery of neurologicalfunction. However, this surgical technique has a relatively large amount of blood loss and high requirements for surgeons.
Objective To investigate the feasibility and effectiveness of selective treatment of senile osteoporotic thoracolumbar burst fractures of Denis type B with kyphoplasty and Jack vertebral dilator. Methods Between August 2007 and May 2011, 30 patients (32 vertebra) with osteoporotic thoracolumbar burst fractures of Denis type B were treated with kyphoplasty and Jack vertebral dilator. There were 7 males and 23 females, aged 57-85 years (mean, 76.9 years). The injured vertebrae included T11 in 2 vertebrae, T12 in 11 vertebrae, L1 in 7 vertebrae, L2 in 5 vertebrae, L3 in 3 vertebrae, and L4 in 4 vertebrae. The visual analogue scale (VAS) score, Oswestry disability index (ODI), the anterior and middle height of the vertebral body, and the Cobb angle were assessed before and after operation. Results The operation was completed smoothly in all cases; no cement leakage or intraoperative complication was found. Obvious back pain relief was achieved in all patients after operation. Thirty patients were followed up at 1 week and 6 months after operation. The VAS score was decreased from 8.2 ± 1.3 before operation to 1.5 ± 0.9 at 1 week after operation and 1.9 ± 0.5 at 6 months after operation; the ODI was decreased from 82.4% ± 15.0% to 17.8% ± 9.5% and 23.0% ± 8.6%; the anterior height of the vertebral body was increased from (19.5 ± 3.2) mm to (24.8 ± 3.0) mm and (24.0 ± 2.6) mm; the middle height of the vertebral body was increased from (18.5 ± 3.4) mm to (23.7 ± 3.7) mm and (22.8 ± 3.5) mm; the Cobb angle was decreased from (14.9± 7.5)° to (7.6 ± 6.0)° and (8.3 ± 6.0)°; and there were significant differences in the VAS score, ODI, the anterior and middle height of the vertebral body, and the Cobb angle between at pre- and at post-operation (P lt; 0.05), but no significant difference between at 1 week and at 6 months after operation (P gt; 0.05). Conclusion Kyphoplasty with Jack vertebral dilator for selective treatment of senile osteoporotic thoracolumbar burst fractures of Denis type B can restore the anterior and middle height of the vertebral body, correct the Cobb angle, and relieve pain, and it has good short-term effectiveness and safety.
Objective To assess the effectivness of different bone graft fusion ways in the treatment of thoracolumbar burst fractures. Methods Between June 2000 and June 2009, 126 cases of thoracolumbar burst fractures were treated by onestageposterior short segment internal fixation combined with bone graft fusion. All patients had acute spine and spinal injuryat the levels of T11-L2, who were with different degrees of neural function injury (below Frankel grade D). The patients were randomly divided into 3 groups and were treated respectively by centrum combined with interbody bone graft fusion (group A), posterolateral bone graft fusion (group B), and ring bone graft fusion (group C) combined with posterior short segment pedicle instrumentation. The changes of the Cobb angle, correction loss of Cobb angle, bone fusion rate, internal fixation failure rate, Oswestry Disabil ity Index (ODI), and Frankel grade of the fracture vertebral were observed after operation to evaluate the effectiveness of different bone graft fusion ways. Results All 126 cases were followed up 24-32 months (mean, 28 months). The operation time and bleeding volume in group C were significantly larger than those in groups A and B (P lt; 0.05), but no significant difference was found between groups A and B (P gt; 0.05). At 2 years after operation and last follow-up, the Cobb angle and correction loss in group B were significantly larger than those in groups A and C (P lt; 0.05), but there was no significant difference between groups A and C (P gt; 0.05). At last follow-up, the bone fusion rate and internal fixation failure rate were 100% and 0 in group A, 78.6% and 21.4% in group B, and 97.5% and 0 in group C; there were significant differences between group B and groups A, C (P lt; 0.05), but no significant difference was found between groups A and C (P gt; 0.05). ODI and Frankel grade were obviously improved after operation, showing significant differences between preoperation and last follow-up (P lt; 0.05) in 3 groups, between group B and groups A, C (P lt; 0.05), but no significant difference was found between groups A and C (P gt; 0.05). Conclusion The centrum combined with interbody bone graft fusion is best in 3 bone graft fusion ways because of its optimum bone fusion and according with human body biomechanics mechanism. Back outboard bone graft fusion may not a appropriate bone fusion way because of its high internal fixation failure rate and not according with human body biomechanics mechanism. The ring bone graft fusion may not be an indispensable bone fusion way because of its common bone fusion ratio and lower cost-performance ratio.
Objective To compare the cl inical effects of indirect decompression versus open decompression to vertebral canal in treatment of thoracolumbar burst fractures without neurologic deficit. Methods From April 2004 to June 2008, 52 cases of thoracolumbar burst fracture without neurologic deficit underwent posterior exposition, reduction and fixation with Atlas Fixator (AF) instrumentation. There were 34 males and 18 females with an average age of 43.1 years (range, 31-63 years). The affectd locations were T11 in 5 cases, T12 in 24 cases, L1 in 16 cases, and L2 in 7 cases. The time from injury to operation was 3-8 days (4.4 days on average). All cases were devided into indirect decompression group (group A) and open decompression group (group B). There were no statistically significant differences (P gt; 0.05) in sex, age, affect site, and disease course between two groups. The operative time, blood loss were recoded. Preoperatively, immediately postoperstively and at last follow-up, the height of the fracture vertebra and the Cobb angle were obtained from X-ray pictures and were statistically analysed. Radiographic parameters on computed tomography (CT) pictures were used to get the encroachment rate of vertebral canal. Results The operative time was (87.3 ± 7.9) minutes and (125.3 ± 13.6) minutes, and the blood loss was (273.7 ± 23.4) mL and (512.6 ± 37.7) mL in groups A and B, respectively; showing statistically significant differences (P lt; 0.05). The average follow-up time was 17.4 months (range, 11-31 months) in group A and 19.9 months (range, 12-33 months) in group B. All wounds achieved primary heal ing postoperatively without deaths and spinal cord injuries. Postoperative compl ications in group B included 3 cases of screws loosening, 1 case of screw breakage, and 3 cases of low back pain, and were given symptomatic management. There were no statistically significant differences (P gt; 0.05) in the height of the fracture vertebra, the Cobb angle andthe encroachment rate of vertebral canal preoperatively or postoperstively between two groups. There were statistically significant differences (P lt; 0.05) in the above three parameters between preoperation and postoperation in two groups, but there were no statistically significant differences (P gt; 0.05) in the spinal correction between two groups. The losing-rate of spinal correction of the height of the fracture vertebra and the Cobb angle of group A was lower than group B, showing statistically significant differences (P lt; 0.05). Conclusion The short-term results of two decompression styles in treatment of thoracolumbar burst fractures without neurologic deficit were satisfactory, but indirect decompression has more merits than open decompression: shorter operative time, less blood loss, lower losing-rate of spinal correction, and better stabil ization of vertebral column.
Objective To explore the injury mechanism of the severethoracolumbar burst fracture and the necessity of anterior decompression and reconstruction with internal fixation. Methods From January 1999 to January 2004, 21 patients were treated with anterior decompression and reconstruction. The fractures were located at T12 in 6 patients, L1 in12, L2 in 4, L3 in 3,and L4 in 1. Four patients were treated with the “anterior approach” and “posterior approach” surgeries for severe column fractures.Results All the patients were restored to the normal physiological radian, and the spinal canal was decompressed completely. They werefollowed up for 1-6 years, and the bony fusion was observed radiologically.The spinal cord function was improved to the 1-3 Frankel grade in all the patients except 2. There were no such complications as leakage of the cerebrospinal fluid, platescrew loosening or breaking, or segment instability. The clinical effects were satisfactory. Conclusion The operation of the anterior decompression and reconstruction with internal fixation for severe thoracolumbar burst fracture has advantages of complete decompression, full bonegrafting, and firm internal fixation. It canrestore the spinal height and improve the spinal cord function.
ObjectiveTo study the effectiveness of posterior laminotomy decompression and bone grafting via the injured vertebrae for treatment of thoracolumbar burst fractures. MethodsBetween November 2010 and November 2012, 58 patients with thoracolumbar burst fractures were treated by posterior fixation combined with posterior laminotomy decompression and intervertebral bone graft in the injured vertebrae. There were 40 males and 18 females with a mean age of 48 years (range, 25-58 years). According to Denis classification, 58 cases had burst fractures (Denis type B); based on neurological classification of spinal cord injury by American Spinal Injury Association (ASIA) classifications, 5 cases were rated as grade A, 18 cases as grade B, 20 cases as grade C, 14 cases as grade D, and 1 case as grade E. Based on thoracolumbar burst fractures CT classifications there were 5 cases of type A, 20 cases of type B1, 10 cases of type B2, and 23 cases of type C. The time between injury and operation was 10 hours to 9 days (mean, 7.2 days). The CT was taken to measure the space occupying of vertebral canal. The X-ray film was taken to measure the relative height of fractured vertebrae for evaluating the vertebral height restoration, Cobb angle for evaluating the correction of kyphosis, and ASIA classification was conducted to evaluate the function recovery of the spinal cord. ResultsThe operations were performed successfully, and incisions healed primarily. All the patients were followed up 12-18 months (mean, 15 months). CT showed good bone graft healing except partial absorption of vertebral body grafted bone; no loosening or breakage of screws and rods occurred. The stenosis rates of fractured vertebral canale were 47.56%±14.61% at preoperation and 1.26%±0.62% at 1 year after operation, showing significant difference (t=24.46, P=0.00). The Cobb angles were (16.98±3.67)° at preoperation, (3.42±1.45)° at 1 week after operation, (3.82±1.60)° at 1 year after operation, and (4.84±1.70)° at 3 months after removal of internal fixation, showing significant differences between at pre-and post-operation (P < 0.05). The relative heights of fractured vertebrae were 57.10%±6.52% at preoperation, 96.26%±1.94% at 1 week after operation, 96.11%±1.97% at 1 year after operation, and 96.03%±1.96% at 3 months after removal of internal fixation, showing significant differences between at pre-and post-operation (P < 0.05). At 1 year after operation, the neural function was improved 1-3 grades in 56 cases. Based on ASIA classifications, 1 case was rated as grade A, 4 cases as grade B, 10 cases as grade C, 23 cases as grade D, and 20 cases as grade E. ConclusionTreatment of thoracic and lumbar vertebrae burst fractures by posterior laminotomy decompression and bone grafting via the injured vertebrae has satisfactory effectiveness, which can reconstruct vertebral body shape and height with spinal cord decompression and good vertebral healing. It is a kind of effective solution for thoracolumbar burst fracture.
ObjectiveTo compare the effective of short-segment pedicle instrumentation with bone grafting and pedicle screw implanting in injured vertebra and cross segment pedicle instrumentation with bone grafting in injured vertebra for treating thoracolumbar fractures. MethodsA prospective randomized controlled study was performed in 40 patients with thoracolumbar fracture who were in accordance with the inclusive criteria between June 2010 and June 2012. Of 40 patients, 20 received treatment with short-segment pedicle screw instrumentation with bone grafting and pedicle screw implanting in injured vertebra in group A, and 20 received treatment with cross segment pedicle instrumentation with bone grafting in injured vertebra in group B. There was no significant difference in gender, age, affected segment, disease duration, Frankel grade, Cobb angle, compression rate of anterior verterbral height, visual analogue scale (VAS) score, and Japanese Orthopaedic Association (JOA) score between 2 groups before operation (P>0.05). The operation time, blood loss, Cobb angle, compression rate of anterior vertebral height, loss of disc space height, Frankel grade, VAS and JOA scores were compared between 2 groups. ResultsThere was no significant difference in the operation time and blood loss between 2 groups (P>0.05). Primary healing of incision was obtained in all patients, and no early complication of infection or lower limb vein thrombus occurred. Forty patients were followed up 12-16 months (mean, 14.8 months). No breaking or displacement of internal fixation was observed. The improvement of Frankel grading score was 0.52±0.72 in group A and 0.47±0.63 in group B, showing no significant difference (t=0.188, P=0.853) at 12 months after operation. The Cobb angle, compression rate of anterior verterbral height, and VAS score at 1 week and 12 months, and JOA score at 12 months were significantly improved when compared with preoperative ones in 2 groups (P<0.05). No significant difference was found in Cobb angle, disc space height, VAS score, and JOA score between 2 groups at each time point (P>0.05), but the compression rate of anterior verterbral height in group A was significantly lower than that in group B (P<0.05). The loss of disc space height next to the internal fixation or the injured vertebra was observed in 2 groups at 12 months, but showing no significant difference (P>0.05). ConclusionCompared with cross segment pedicle instrumentation, short-segment pedicle screw instrumentation with bone grafting and pedicle screw implanting in injured vertebra can recover and maintain the affected vertebra height in treating thoracolumbar fractures, but it could not effectively prevent degeneration of adjacent segments and the loss of kyphosis correction degree.
ObjectiveTo investigate the effects of anterior single segment fixation on the spinal biomechanical stabilization in the treatment of thoracolumbar burst fracture of Denis type B with pedicle injury. MethodsSix fresh human cadaveric spine specimens (T11-L3) were harvested as normal control (group A). Then the L1 Denis type B fracture model was created by the hemi-corpectomy method. Each specimen was tested in 3 different scenarios: anterior single segment (T12, L1) fixation with the integrity of the pedicle (group B), anterior single segment fixation with the resection of the unilateral pedicle (group C), and anterior single segment fixation with the resection of the bilateral pedicles (group D). Range of motion (ROM) in flexion/extension, bilateral bending, and bilateral axial rotation was measured by spinal three-dimensional measuring system under pure moments of 8.0 N·m. ResultsThe ROM values of T12, L1 in flexion, extension, and right/left lateral bending of groups B, C, and D were significantly lower than those of group A (P<0.05); group D was significantly higher than groups B and C (P<0.05); but groups B and C showed no significant difference (P>0.05). The ROM values of T12, L1 in right/left axial rotation of groups B and C were significantly lower than those of groups A and D (P<0.05), but there was no significant difference (P>0.05) between groups B and C and between groups A and D. The ROM values of L1, 2 in flexion, extension, right/left lateral bending, and right/left axial rotation showed no significant difference between groups (P>0.05). ConclusionResection of the unilateral pedicle has litter effects on the spine biomechanical stabilization of the anterior single segment fixation in the 6 degrees of freedom. However, the bilateral resection results show significant decrease in flexion, extension, lateral bending, and rotation motion stability by the single segment fixation devices, especially in the axial rotation aspect.