Cervical myelopathy caused by invaginated laminae of the axis associated with occipitalizaion of the atlas: Case report and literature review.

RATIONALE: In previous studies, few cases of cervical myelopathy caused by invaginated anomalous laminae of the axis have been reported, and none of them was combined with occipitalization of the atlas. PATIENT CONCERNS: A 28-year-old male was brought to our hospital with motor and sensory impairments of the extremities after a car accident. DIAGNOSES: MRI showed the spinal cord was markedly compressed at the C2/3 level. Reconstructed CT scans revealed an invaginated laminae of axis into the spinal canal as well as atlas assimilation. INTERVENTIONS: The patient was successfully managed with surgical treatment by removal of the anomalous osseous structure as well as fixation and fusion. OUTCOMES: The patient had a rapid recovery after the operation. He regained the normal strength of his 4 extremities and the numbness of his extremities disappeared. He returned to his normal work 3 months after the surgery without any symptoms. LESSONS: Invaginated laminae of axis combined with occipitalization of the atlas is a rare deformity. MRI and reconstructed CT scans are useful for both diagnosing and surgical planning of this case. Surgical removal of the laminae results in a satisfactory outcome. The pathogenesis of this anomaly could be the fusion sequence error of the 4 chondrification centers in the embryological term.

Comparison of Cervical Spine Anatomy in Calves, Pigs and Humans.

BACKGROUND CONTEXT: Animals are commonly used to model the human spine for in vitro and in vivo experiments. Many studies have investigated similarities and differences between animals and humans in the lumbar and thoracic vertebrae. However, a quantitative anatomic comparison of calf, pig, and human cervical spines has not been reported. PURPOSE: To compare fundamental structural similarities and differences in vertebral bodies from the cervical spines of commonly used experimental animal models and humans. STUDY DESIGN: Anatomical morphometric analysis was performed on cervical vertebra specimens harvested from humans and two common large animals (i.e., calves and pigs). METHODS: Multiple morphometric parameters were directly measured from cervical spine specimens of twelve pigs, twelve calves and twelve human adult cadavers. The following anatomical parameters were measured: vertebral body width (VBW), vertebral body depth (VBD), vertebral body height (VBH), spinal canal width (SCW), spinal canal depth (SCD), pedicle width (PW), pedicle depth (PD), pedicle inclination (PI), dens width (DW), dens depth (DD), total vertebral width (TVW), and total vertebral depth (TVD). RESULTS: The atlantoaxial (C1-2) joint in pigs is similar to that in humans and could serve as a human substitute. The pig cervical spine is highly similar to the human cervical spine, except for two large transverse processes in the anterior regions ofC4-C6. The width and depth of the calf odontoid process were larger than those in humans. VBW and VBD of calf cervical vertebrae were larger than those in humans, but the spinal canal was smaller. Calf C7 was relatively similar to human C7, thus, it may be a good substitute. CONCLUSION: Pig cervical vertebrae were more suitable human substitutions than calf cervical vertebrae, especially with respect to C1, C2, and C7. The biomechanical properties of nerve vascular anatomy and various segment functions in pig and calf cervical vertebrae must be considered when selecting an animal model for research on the spine.

Transforaminal decompression and interbody fusion in the treatment of thoracolumbar fracture and dislocation with spinal cord injury.

STUDY DESIGN: A retrospective clinical study. OBJECTIVE: To evaluate the efficacy and safety of transforaminal decompression and interbody fusion in the treatment of thoracolumbar fracture and dislocation with spinal cord injury. METHODS: Twenty-six spinal cord injured patients with thoracolumbar fracture and dislocation were treated by transforaminal decompression and interbody fusion. The operation time, intraoperative blood loss, and complications were recorded; the Cobb angle and compressive rate (CR) of the anterior height of two adjacent vertebrae were measured; and the nerve injury was assessed according to sensory scores and motor scores of the American Spinal Injury Association (ASIA) standards for neurological classification of spinal cord injury. RESULTS: The operative time was 250±57 min, and intraoperative blood loss was 440±168 ml. Cerebrospinal leakage was detected and repaired during the operation in two patients. A total of 24 of 26 patients were followed up for more than 2 years. ASIA sensory scores and motor scores were improved significantly at 3 months and 6 months after operation; the Cobb angle and CR of the anterior height of two adjacent vertebrae were corrected and showed a significant difference at post-operation; and the values were maintained at 3 months after operation and the last follow-up. CONCLUSION: We showed that transforaminal decompression together with interbody fusion is an alternative method to treat thoracolumbar fracture and dislocation.

Pooled analysis of non-union, re-operation, infection, and approach related complications after anterior odontoid screw fixation.

BACKGROUND: Anterior odontoid screw fixation (AOSF) has been one of the most popular treatments for odontoid fractures. However, the true efficacy of AOSF remains unclear. In this study, we aimed to provide the pooled rates of non-union, reoperation, infection, and approach related complications after AOSF for odontoid fractures. METHODS: We searched studies that discussed complications after AOSF for type II or type III odontoid fractures. A proportion meta-analysis was done and potential sources of heterogeneity were explored by meta-regression analysis. RESULTS: Of 972 references initially identified, 63 were eligible for inclusion. 54 studies provided data regarding non-union. The pooled non-union rate was 10% (95% CI: 7%-3%). 48 citations provided re-operation information with a pooled proportion of 5% (95% CI: 3%-7%). Infection was described in 20 studies with an overall rate of 0.2% (95% CI: 0%-1.2%). The main approach related complication is postoperative dysphagia with a pooled rate of 10% (95% CI: 4%-17%). Proportions for the other approach related complications such as postoperative hoarseness (1.2%, 95% CI: 0%-3.7%), esophageal/retropharyngeal injury (0%, 95% CI: 0%-1.1%), wound hematomas (0.2%, 95% CI: 0%-1.8%), and spinal cord injury (0%, 95% CI: 0%-0.2%) were very low. Significant heterogeneities were detected when we combined the rates of non-union, re-operation, and dysphagia. Multivariate meta-regression analysis showed that old age was significantly predictive of non-union. Subgroup comparisons showed significant higher non-union rates in age ≥ 70 than that in age ≤ 40 and in age 40 to <50. Meta-regression analysis did not reveal any examined variables influencing the re-operation rate. Meta-regression analysis showed age had a significant effect on the dysphagia rate. CONCLUSIONS/SIGNIFICANCES: This study summarized the rates of non-union, reoperation, infection, and approach related complications after AOSF for odontoid fractures. Elderly patients were more likely to experience non-union and dysphagia.

Fusion versus nonfusion for surgically treated thoracolumbar burst fractures: a meta-analysis.

BACKGROUND: Posterior pedicle screw fixation has become a popular method for treating thoracolumbar burst fractures. However, it remains unclear whether additional fusion could improve clinical and radiological outcomes. This meta-analysis was performed to evaluate the effectiveness of fusion as a supplement to pedicle screw fixation for thoracolumbar burst fractures. METHODOLOGY/PRINCIPAL FINDINGS: MEDLINE, OVID, Springer, and Google Scholar were searched for relevant randomized and quasi-randomized controlled trials that compared the clinical and radiological efficacy of fusion versus nonfusion for thoracolumbar burst fractures managed by posterior pedicle screw fixation. Risk of bias in included studies was assessed using the Cochrane Risk of Bias tool. We generated pooled risk ratios or weighted mean differences across studies. Based on predefined inclusion criteria, 4 eligible trials with a total of 220 patients were included in this meta-analysis. The mean age of the patients was 35.1 years. 96.8% of the fractures were located at T12 to L1 level. Baseline characteristics were similar between the fusion and nonfusion groups. No significant difference was identified between the two groups regarding radiological outcome, functional outcome, neurologic improvement, and implant failure rate. The pooled data showed that the nonfusion group was associated with significantly reduced operative time (p<0.0001) and blood loss (p  = 0.0003). CONCLUSIONS/SIGNIFICANCES: The results of this meta-analysis suggested that fusion was not necessary when thoracolumbar burst fracture was treated by posterior pedicle screw fixation. More randomized controlled trials with high quality are still needed in the future.

[Discectomy and discectomy plus Coflex fixation for lumbar disc herniation, a clinical comparison study].

OBJECTIVE: To compare clinical efficacy between discectomy and discectomy plus Coflex fixation for lumbar disc herniation. METHODS: From December 2007 to August 2008, 50 patients (31 males and 19 females) were treated by surgery of discectomy and discectomy plus Coflex fixation. The average age was 52.5 years (range, 30 - 72 years). There were 24 cases in the group of discectomy plus Coflex fixation and 26 cases in the group of discectomy. Preoperative and postoperative visual analogue scales (VAS), Japanese Orthopadic Association (JOA) and Oswestry disability index (ODI) were recorded, as well as radiological index. And use a paired t-test and one-way analysis of variance (one-way ANOVA) statistical method to evaluate the Coflex dynamic stabilization system in value in the treatment of lumbar disc herniation. RESULTS: Both groups received significant improvement of JOA, ODI and VAS (t = -33.2 - 64.5, P < 0.01), but the group of discectomy was found with deterioration of ODI at last follow-up, 12 months after surgery 6.7 ± 1.5 to 10.2 ± 2.3 (t = -19.3, P < 0.05). The group of discectomy plus Coflex fixation was found with significant increase of height of dorsal intervertebral discs (HD), distance across the two adjacent spinous processes (DS), distance of intervertebral foramina (DIF) and spinal canal area(SA) (t = -34.4 - 4.5, P < 0.05). In contrast, the group of discectomy was found with significant decrease of HD, DS, DIF and SA (t = 3.4 - 52.8, P < 0.05). Coflex fixed group in HD, DIF, DS significant difference with simple discectomy group, with a statistically significant (F = 14.1 - 25.6, P < 0.05). CONCLUSIONS: Both discectomy and discectomy plus Coflex fixation are apparently effective when treating lumbar disc herniation. Coflex can significantly increase the HD and DIF when used for lumbar disc herniation, and it has positive influence for keeping height of lumbar vertebral space and treating the nerve root symptom of lumbar disc herniation. Discectomy plus Coflex is better than pure discectomy in preventing lumbar degeneration.

Minimally invasive versus open transforaminal lumbar interbody fusion: a meta-analysis based on the current evidence.

PURPOSE: This is a meta-analysis of randomized and non-randomized studies comparing the clinical and radiological efficacy of minimally invasive (MI) and conventional open transforaminal lumbar interbody fusion (open-TLIF) for degenerative lumbar diseases. METHODS: A literature search of the MEDLINE database identified 11 studies that met our inclusion criteria. A total of 785 patients were examined. Pooled estimates of clinical and radiological outcomes, and corresponding 95% confidence intervals were calculated. RESULTS: The pooled data revealed that MI-TLIF was associated with less blood loss, shorter hospital stay, and a trend of better functional outcomes when compared with open-TLIF. However, MI-TLIF significantly increased the intraoperative X-ray exposure. Both techniques had similar operative time, complication rate, and re-operation rate. CONCLUSIONS: Based on the available evidence, MI-TLIF for degenerative lumbar diseases might lead to better patient-based outcomes. MI-TLIF would be a promising procedure, but extra efforts are needed to reduce its intraoperative radiation exposure. More randomized controlled trials are needed to compare these two surgical options.

[Clinical evaluation of interspinous process device Coflex for degenerative disk diseases].

OBJECTIVE: To study indications and complications of interspinous process device Coflex for degenerative disk diseases. METHODS: One hundred and eight patients with degenerative lumbar disc diseases were underwent procedures of surgical decompression and additional fixation of Coflex between November 2007 and October 2010. Sixty-eight patients were male and the other fourty were female, and their average age was 53.5 years (range from 37 to 75 years). Fifty-nine patients were underwent surgery of excision of nucleus pulposus and Coflex fixation, 41 patients were underwent surgery of decompression by fenestration and Coflex fixation, 6 patients were underwent surgery of topping-off, and 2 patients were underwent surgery of Coflex fixation for two level. Preoperative and postoperative visual analogue scales (VAS) and Oswestry disability index (ODI) were recorded, as well as height of ventral intervertebral space (HV), height of dorsal intervertebral space (HD), height of intervertebral foramen (HIF) and segmental range of motion (ROM). One-way ANOVA was used for statistical analysis. Surgical complications were also recorded. RESULTS: The average follow-up time was 28.8 months. All groups had apparent improvement of VAS and ODI, and maintained well to last follow-up (F = 6.16-25.92, P = 0.00). Statistical analysis showed that HD and HIF increased significantly in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation (F = 7.37 - 11.68, P < 0.05). Although both HD and HIF decreased one-year after surgery, they were still higher than those preoperatively (F = 6.31 and 7.05, P = 0.00). Preoperative segmental ROM was respectively 6.3° ± 1.8° and 6.2° ± 1.7° in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation, and 3.1° ± 0.6° and 3.0° ± 0.8° at last follow-up. Three cases were found with device-related complications and five with non-device-related complications, and all five cased were cured after appropriate treatment. CONCLUSIONS: Surgical method assisted with Coflex has significant clinical efficacy for degenerative disc disease, it can maintain segmental stability, simultaneously, partly reserve movement. It's key to strictly master indications and precisely choose patients.

[Influence of intravertebral cleft for outcome of percutaneous kyphoplasty].

OBJECTIVES: To study incidence and radiological features of intravertebral cleft (IVC) in patients with chronic pain due to osteoporotic vertebral compression fractures (OVCFs), and analyze influence of IVC for surgery of percutaneous kyphoplasty (PKP). METHODS: Seventy-six patients with osteoporotic vertebral compression fractures and pain duration more than one month were underwent procedures of PKP between August 2005 and August 2010. The incidence and radiological features of IVC were analyzed. Sixty-one patients with single-level OVCFs were divided into two groups with and without IVC. Preoperative and postoperative kyphotic angle and relative anterior vertebral height were recorded, as well as visual analogue scales (VAS) and Oswestry disability index (ODI). Cement patterns of opacification and leakage were also recorded. RESULTS: Thirty two patients with 39 vertebrates were found with IVC sign. The diagnostic sensitivity of X ray, CT and MRI for IVC was respectively 33.3%, 85.7% and 84.6%. Two groups with IVC and without IVC both had apparent correction of kyphotic angle and reduction of anterior height at 3 days after surgery and last follow-up (F = 21.82 - 72.18, P < 0.01). There was no statistical significance between two groups (P > 0.05). In addition, both groups had significant improvement as regard to VAS and ODI (F = 131.06 - 364.12, P < 0.01). Solid pattern accounted for 72.0% of all cemented vertebrates in the group with IVC and 19.4% in the group without IVC. Four cement leakage were found in the group with IVC and another four in the group without IVC. CONCLUSIONS: There is a high incidence of IVC in patients with chronic pain due to osteoporotic vertebral compression fractures. CT and MRI are sensitive for detection of IVC. The procedure of PKP is effective for both groups with and without IVC. IVC produces an apparent influence on cement opacification and leakage location during the procedure of PKP.

[Prediction of spinal cord decompression after cervical laminoplasty: the SC-line].

OBJECTIVES: To report a new index (the SC-line) and a new classification for predicting of postoperative spinal cord decompression after cervical laminoplasty. METHODS: From March 2008 to August 2009, MRI images of 25 patients treated with cervical laminoplasty were retrospectively studied. Using T2-weighted images of the cervical spine, point A was anterior point of the spinal cord at inferior endplate level of cranial compressed vertebra. Point B was anterior point of the spinal cord at superior endplate level of caudal compressed vertebra. The SC-line was defined as a line that connects A and B. Posterior surface of compressor at compression level did not exceed the line in Type I, connected the line in Type II, and exceeded it in Type III. Twenty-five patients who underwent cervical laminoplasty were classified into 3 groups according to the SC-line classification. The posterior shift of the spinal cord after the posterior decompression procedure was evaluated by using a modified gradation of degree of anterior spinal cord compression by MRI finding. The relationship between the degree of anterior spinal cord compression after surgery and the SC-line types were analyzed. RESULTS: Preoperative cervical SC-line classification showed high correlations to the degree of spinal cord decompression. There were 3.82 ± 0.39 points in Type I before surgery, 3.90 ± 0.32 points in Type II, and 4.00 ± 0.00 points in Type III, respectively. After surgery, there were 1.15 ± 0.50 points in Type I, 2.70 ± 0.48 points in Type II, and 3.50 ± 0.55 points in Type III, respectively. Significant differences were found between each Type (F = 42.49, P < 0.01; Type I vs. Type II: P < 0.01; Type I vs. Type III: P < 0.01; Type II vs. Type III: P = 0.038). CONCLUSION: SC-line can be used to predict the degree of postoperative spinal cord decompression following cervical laminoplasty.

[Therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures].

OBJECTIVE: To investigate the therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures. METHODS: From January 2002 to December 2008, 103 patients with thoracolumbar fractures were treated with percutaneous pedicle screw fixation, including 75 males and 28 females, the average age was 45.6 years (range, 18 - 72 years). All of them were of no neurological deficits. There were 65 cases of traffic injury, 23 cases of fall injury and 15 cases of smashed injury. According to the Denis classification, 64 patients were of compression fractures, and 39 patients of burst fractures. There were 5 cases had fractures in T(11), 30 in T(12), 42 in L(1), 15 in L(2), 4 in L(3), 3 in L(4), 2 in T(11-12), 1 in L(1-2), and 1 in L(2-3). Radiological examinations, including X-ray and CT examinations, and clinical examinations were carried out to evaluate the therapeutic effects. RESULTS: Twenty one patients were lost to follow up, the remaining were followed up from 10 to 48 months with an average of 27.4 months. Before the operation, the vertebral height, the kyphosis angle and the occupation of spinal canal were (54.5 ± 8.7)%, 16.4° ± 2.9° and 1.2 ± 1.0, and were improved to (88.6 ± 6.4)%, 11.6° ± 2.7° and 0.5 ± 0.6 respectively after the operation. Preoperatively the visual analogue scale and the Oswestry disability index were 8.0 ± 1.2 and 41.2 ± 9.3, and were improved to 1.7 ± 1.8 and 6.7 ± 5.6 postoperatively, respectively. All of these values between pre- and post-operatively were significantly different (P < 0.01). Screw misplacement was found in 7 patients, superficial wound infection in 1, screw breakage in 3, screw dislodgment in 2, cement leakage in 5, transient neurological symptoms in 4, and 8 patients with low back pain remained, of which 2 patients required occasional oral analgesics. Bone fusion achieved in all cases. CONCLUSIONS: The clinical efficacy of percutaneous pedicle screw fixation is similar with conventional open surgery. With the advantages of convenient procedure, less invasive, and rapid recovery, percutaneous pedicle screw fixation is an alternative method for thoracolumbar fractures without neurological deficits.

[The application of minimally invasive surgery for different type of thoracolumbar fractures].

OBJECTIVE: To study the therapeutic method and effect of minimally invasive surgery for the thoracolumbar fractures. METHODS: A retrospective review of the minimally invasive surgically treatment thoracolumbar fractures from February 2005 to June 2010 was performed. There were 183 cases, 126 males and 57 females, aged 18 to 68 years, average 38.9 years. The involved levels of fractures were T(11) in 22, T(12) in 61, L(1) in 71, L(2) in 29. According to Gertzbein classification, 145 cases were type A fractures, 34 cases were type B fractures, 4 cases were type C fractures; According to Load-sharing score, 51 cases were 4 scores, 56 cases were 5 scores, 17 cases were 6 scores, 12 cases were 7 scores, 24 cases were 8 scores, 23 cases were 9 scores. Different surgical methods were selected according to the minimally invasive surgical strategy, 22 patients were treated with the minimally invasive percutaneous pedicle screws osteosynthesis (MIPPSO group), 102 patients were treated with the small-incision pedicle screws osteosynthesis (SISPSO group), 31 patients were treated with the small incision anterior thoracolumbar surgery (SIATS group) assisted by thoracoscope or headlight, and 28 patients were treated with the 270° decompression and reconstruction surgery (270° DRS group) via a posterior small incision. Preoperative and postoperative neurological status, the correction and loss of Cobb's angle, the decompression scope of spinal canal, the location and union of bone graft were followed up and reviewed. RESULTS: All of 183 cases had successful surgery and were followed up. In the MIPPSO group, operative time was 52 - 100 min, blood loss was 35 - 55 ml. In the the SISPSO group, operative time was 48-68 min, the blood loss was 45 - 65 ml the correction of Cobb's angle in the two groups was 8° - 19°. In the SIATS group, operative time was 140 - 220 min, the blood loss was 160 - 1500 ml the correction of Cobb's angle was 15° - 25°, 1 case had pleural effusion, 1 had lateral femoral cutaneous nerve damage, the complications disappeared after treatment. In the 270° DRS group the operative time was 160-280 min, the blood loss was 700 - 4700 ml, the correction of Cobb's angle was 15° - 28°. The spinal canal mass was removed, the spinal canal was enlarged and completely decompressed. Neurological status improved in all of the preoperative incomplete paraplegia patients except 1 case whose neurological symptoms aggravated. CONCLUSION: It is satisfactory that the minimally invasive surgical strategy was rational used in the treatment of thoracolumbar fractures.

Percutaneous pedicle screw fixation for neurologic intact thoracolumbar burst fractures.

STUDY DESIGN: Prospective consecutive series. OBJECTIVE: To evaluate the efficacy and safety of percutaneous pedicle screw fixation (PPSF) for thoracolumbar AO type A3 fractures with a specially designed surgical instrument system. SUMMARY OF BACKGROUND DATA: Minimally invasive surgery including PPSF is becoming increasingly widespread in the spine surgery. The technique of PPSF was mostly used as supplemental fixation combined with minimally invasive posterior or anterior lumbar interbody fusion in management of lumbar degenerative disorders. There are fewer studies available in literature regarding PPSF without additional kyphoplasty or vertebroplasty for management of thoracolumbar burst fractures. METHODS: Thirty-six adult patients, who had single thoracolumbar AO type A3 fractures and the load-sharing score of 6 or less, underwent application of percutaneous short-segment pedicle screw fixation. Radiologic parameters including kyphotic angle and vertebral height loss were assessed before and after surgery, and functional outcome was evaluated by Prolo questionnaire. RESULTS: All patients were successfully managed with percutaneous minimal invasive procedures. The average operative time was 78 minutes (range 62 to 117 min). The average intraoperative blood loss was 75 mL (range 50 to 220 mL). After a mean follow-up of 48.5 months (range 32 to 63 mo), 31 of 36 (86.1%) patients had a satisfactory result (19 excellent and 12 good) and 5 of them fair. CONCLUSIONS: Our clinical results suggest that PPSF can be an alternative for management of thoracolumbar AO type A3 fractures that have no neurologic deficits. With a specially designed percutaneous instrument and pedicle screw system, the procedure has been proved as relatively safe and a minimally invasive approach for the management of thoracolumbar burst fracture without neurologic deficit.

Microendoscopic anterior approach for irreducible atlantoaxial dislocation: surgical techniques and preliminary results.

STUDY DESIGN: Surgical techniques and preliminary results. OBJECTIVE: To describe and evaluate the safety and efficacy of a new minimal invasive technique for the irreducible atlantoaxial dislocation (IADD). SUMMARY OF BACKGROUND DATA: Endoscope has been widely used in minimal invasive spinal surgery. However, there are no clinical reports regarding anterior approach for IADD in the literature. METHODS: Ten consecutive patients with IADD were treated by anterior release with microendoscopic aide and subsequently reduction, anterior transarticular screw fixation and morselized autologous bone grafts. There were 3 cases of odontoid dysplasia, 4, chronic odontoid fracture, 1, odontoid absence, 1 fasilar impression, and 1 malunion of odontoid fracture. According to Symon and Lavender's classification of disability, 6 cases were moderate disability, 3 severe nonbedbound, and 1 severe bedridden. The procedure was performed by the same surgeon (Yong-Long Chi). RESULTS: The new technique was performed successfully in all cases. All the patients underwent transarticular screw fixation and anterior morselized autograft fusion. The average operation time was 120 min (range, 90 to 150 min) and the mean estimated blood loss was 150 mL (range, 100 to 250 mL). Postoperative radiographs demonstrated that 9 cases restored anatomic position and 1 had partial reduction. According to the postoperative computed tomography all the screws were appropriately placed. Follow-up after surgery, longest is 16 months and minimal 8 months with a mean of 12 months, neurologic status was improved in all patients. There was no loss of fixation and solid fusion was achieved in all cases. CONCLUSIONS: Surgical technique of microendoscopic anterior release, reduction, fixation, and fusion is safe and reliable minimally invasive for treating IADD.

[Comparative percutaneous with open pedicle screw fixation in the treatment of thoracolumbar burst fractures without neurological deficit].

OBJECTIVE: To compare clinical outcome of the percutaneous versus open pedicle screw fixation in the treatment of thoracolumbar burst fracture with neurological intact. METHODS: Sixty patients with thoracolumbar burst fracture without neurological deficit underwent either percutaneous (n = 30) or traditional open pedicle screw fixation (n = 30). Radiographs obtained before surgery, immediately after surgery, 4 months and 2 years after surgery were used to access the restoration of spinal anatomy. Also, operation time, blood loss, blood drainage, hospital stay and soft tissue dissection were evaluated. The level of pain was assessed by visual analog scale (VAS), function by the Oswestry questionnaire. RESULTS: The average followed up was 2 years. There were no significant differences between both groups concerning age, sex, cause of injury and the presence of other severe injuries. Significant differences were observed between the two groups in blood loss, blood drainage, hospital stay and soft tissue dissection (P < 0.01), whereas no significant differences in operation time (P > 0.05). The vertebral height, the kyphosis angle, and the occupation of spinal canal after surgery and at follow-up were not significantly (P > 0.05). The pain systems and functions were similar in both groups at final follow-up (P > 0.05), however, less pain was found in the percutaneous group than that in the open group at the first 3 months after surgery (P < 0.01). CONCLUSION: Percutaneous pedicle screw fixation for thoracolumbar fracture has the advantage of less trauma, quickly recovery and better esthetic outcome, however, it has the same results with the traditional open produce after 2 years of surgery.

[Comparison of the paraspinal muscle change of percutaneous and open pedicle screw fixation in the treatment for thoracolumbar fractures].

OBJECTIVES: To compare short-term and long-term change of paraspinal muscle between percutaneous and open pedicle screw fixation in the treatment of thoracolumbar fractures. METHODS: Thirty-three patients were divided into four groups: short-term percutaneous pedicle screw fixation group, short-term open pedicle screw fixation group, long-term percutaneous pedicle screw fixation group, and long-term open pedicle screw fixation group. Paraspinal muscle were studied by needle electromyography and CT. Cross-sectional area and color grade information of paraspinal muscle were measured using CT image. RESULTS: The area and color grade of paraspinal muscle changed significantly after surgery. The color grade of paraspinal muscle showed significant change while the muscle area observed no significant change in the two short-term groups; There was significant change in paraspinal muscle area, however no significant change was found in muscle color grade of the two long-term groups. In electromyography study the results showed that there was significant difference in the two short-term groups, however no significant difference existed in the long-term groups. There was no significant difference of patients treated by the two surgical technique in long-term function evaluation. CONCLUSION: Both percutaneous and open pedicle screw fixation damage paraspinal muscle, however the muscle showed less injury treated by percutaneous pedicle fixation.

[Percutaneous microendoscopic anterior release, fixation and fusion for irreducible atlanto-axial dislocation].

OBJECTIVE: To evaluate the safety and efficacy of one-stage percutaneous microendoscopic anterior release, trans-articular fixation and fusion to reduce and stabilize for irreducible atlanto-axial dislocation. METHODS: Eight consecutive patients were treated by percutaneous microendoscopic anterior release, trans-articular C(1-2) fixation and bone graft fusion. The mean age was 33 years (range, 28-52 years). The pathology included odontoid dysplasia in 3 patients, chronic odontoid fractures in 2, odontoid absence in 1, fasilar impression in 1 and malunion of odontoid fracture in 1. The classification of disability was that proposed by Symon and Lavender. There were moderate disability in 4, severe non-bedbound in 3, and severe bedridden in 1. RESULTS: The new technique was performed successfully in all cases. All patients underwent trans-articular C(1-2) screw fixation and anterior bone graft fusion. The average operation time was 120 min (90-150 min), and the average estimated blood loss was 150 ml (100-250 ml). Seven cases resulted in anatomic reduction, 1 had partial reduction. The follow-up period was 8-16 months. The effective rate was 100%, and the excellent rate was 51.25%; the average improvement rate for the spinal canal decompression was 76.5%. There was no instrument failure or pseudarthrosis, and solid fusion was achieved in the all cases. The loss of axial rotation of cervical spine was 30-40 degrees . CONCLUSION: Percutaneous microendoscopic anterior release, fixation and fusion is an effective, reliable, and safe procedure for the treatment of irreducible atlanto-axial dislocation.

Management of odontoid fractures with percutaneous anterior odontoid screw fixation.

Minimally invasive techniques have revolutionized the management of a variety of spinal disorders. The authors of this study describe a new instrument and a percutaneous technique for anterior odontoid screw fixation, and evaluate its safety and efficacy in the treatment of patients with odontoid fractures. Ten patients (6 males and 4 females) with odontoid fractures were treated by percutaneous anterior odontoid screw fixation under fluoroscopic guidance from March 2000 to May 2002. Their mean age at presentation was 37.2 years (with a range from 21 to 55 years). Six cases were Type II and four were Type III classified by the Anderson and D'Alonzo system. The operation was successfully completed without technical difficulties, and without any soft tissue complications such as esophageal injury. No neurological deterioration occurred. Satisfactory results were achieved in all patients and all of the screws were in good placement. After a mean follow-up of 15.7 months (range 10-25 months), radiographic fusion was documented for 9 of 10 patients (90%). Neither clinical symptoms nor screw loosening or breakage occurred. Our preliminary clinical results suggest that the percutaneous anterior odontoid screw fixation procedure using a new instrument and fluoroscopy is technically feasible, safe, useful, and minimally invasive.