Vitexin alleviates ER-stress-activated apoptosis and the related inflammation in chondrocytes and inhibits the degeneration of cartilage in rats.

Excessive extracellular matrix degradation and chondrocyte apoptosis are the pathological features of osteoarthritis (OA). The ability of flavonoid compounds isolated from Chinese hawthorn leaves to exert protective effects on several diseases, via inhibition of oxidative stress and inflammation, has been demonstrated in several studies. This study explored the effects of vitexin on chondrocytes, and the underlying mechanisms thereof. Vitexin, an active ingredient in hawthorn leaf extracts, was shown to exert protective effects on chondrocytes, by inhibiting the expression of GRP78 and PDI, and an apoptotic protein (CHOP) induced by interleukin-1ß. It also modulated thapsigargin-induced upregulation of GRP78 and PDI and subsequently an apoptotic protein (CHOP). Among rat chondrocytes, both the ER stress-activated nuclear factor kappa B (NF-κB) pathway and the induced expression of inflammatory cytokines (IL-6 and TNF-α) were significantly inhibited by vitexin. Finally, vitexin attenuated the progression of OA in vivo in rats. Taken together, all data demonstrate the relationship of ER stress and inflammation in the progression of OA, the ability of vitexin to protect chondrocytes and thus its therapeutic potential in patients with OA.

Risk Factor of Failed Reduction of Posterior Ligamentatoxis Reduction Instrumentation in Managing Thoracolumbar Burst Fractures: A Retrospective Study.

OBJECTIVE: To determine whether radiographic findings associated with thoracolumbar burst fractures could be predictors of failure of short-segment posterior instrumentation with insertion screw at the fracture level (SSPI-f). METHODS: Seventy-five patients with thoracolumbar burst fracture surgically treated by SSPI-f were enrolled in the study and divided into 2 groups: a reduction group (n = 46) and a failed-reduction group (n = 29). Radiographic data including local kyphosis, Cobb angle, anterior vertebral height, posterior vertebral height (PVH), anterior/posterior vertebral height ratio, interpedicle distance (IPD), bony compress area, bony fracture area, and compress-fracture area of the fractured vertebra and clinical data including age and neurologic function were also analyzed. t test, Pearson χ2 test, and binary logistic regression were performed to compare the values. RESULTS: The PVH in the failed-reduction group was smaller than that of the reduction group (83.5% ± 7.2% and 89.1% ± 5.4%, respectively) (P = 0.001). The IPD differed between the reduction and failed-reduction group (18.0% ± 4.1% and 25.8% ± 7.1%, respectively) (P < 0.001). There was a statistical difference between the 2 groups in delayed time before surgery (P = 0.008). There was a significant difference of bony fracture area and compress-fracture area of the fractured vertebra between the failed-reduction and reduction group (both P < 0.001). Binary logistic regression showed that IPD was a risk factor of reduction failure of SSPI-f (P = 0.001). CONCLUSIONS: These results showed that increased IPD was a risk factor of failed-reduction of SSPI-f in managing thoracolumbar burst fractures, particularly for patients with neurologic deficit, whereas local kyphosis, Cobb angle, anterior vertebral height, PVH, anterior/posterior vertebral height ratio, bony compress area, bony fracture area, and compress-fracture area of the fractured vertebra were not.

Comparison of minimally invasive and open transforaminal lumbar interbody fusion in the treatment of single segmental lumbar spondylolisthesis: minimum two-year follow up.

BACKGROUND: Compare the efficacy and safety of minimally invasive and open transforaminal lumbar interbody fusion (TLIF) in the treatment of single segmental lumbar spondylolisthesis. METHODS: From 2010-01 to 2015-10, in total, 167 patients with single segmental spondylolisthesis treated by TLIF were included, 79 cases in minimally invasive TLIF (MI-TLIF) group and 88 cases in open TLIF group. The peri-operative parameters of operative time, estimated blood loss and length of postoperative hospital stay was recorded, as well as complications. Visual Analogue Scale (VAS) of low back pain and leg pain, and Oswestry Disability Index (ODI) were used to assess the pain and functional outcomes at pre-operatively, 3 months/1 year/2 years/5 years after operation. The radiographic parameters of posterior height of the intervertebral space and segmental lordosis were measured too. RESULTS: No significantly difference was found at baseline characteristic data of age, gender ratio, the percentage of degenerative and isthmic spondylolisthesis, the percentage of slip, and segmental distribution between MI-TLIF and open TLIF groups. MI-TLIF group had less estimated intra-operative blood loss (163.7±49.6 mL) than open TLIF group (243.3±70.2 mL, P<0.001) and had shorter post-operative hospital stay (5.8±1.4 days) than open TLIF group (7.3±2.9 days, P<0.001). Both MI-TLIF and open TLIF can significantly reduce the VAS of low back pain, VAS of leg pain, ODI, and improve the posterior height of the intervertebral space and segmental lordosis, but no significantly difference was found of them between two groups. CONCLUSIONS: Our study suggests that MI-TLIF is a safe and effective choice in the treatment of lower grade lumbar spondylolisthesis (grade II or less), and it has advantages of less blood loss, postoperative hospital stay when compared to open TLIF.

The outcomes of percutaneous kyphoplasty in treatment of the secondary osteoporotic vertebral compression factures: a case-control study.

BACKGROUND: To investigate the outcomes of using percutaneous kyphoplasty in the treatment of the secondary osteoporotic vertebral compression fractures. METHODS: Eighty-one patients had the secondary single segmental osteoporotic vertebral compression fractures after the initial fractures and treated by percutaneous kyphoplasty were reviewed, 74 of them had minimum 2 years follow-up were included in this study. The 74 patients with primary osteoporotic vertebral compression fractures treated by percutaneous kyphoplasty at the same time period were matched as control group in 1:1 ratio. Visual Analogue Scales (VAS) and Oswestry Disability Index (ODI) were used to assess the back pain and functional outcomes. The kyphotic angulation (KA) and compression ratio (CR) of the fractured vertebra was measured too. RESULTS: Both the secondary fracture group and control group had significantly relieved back pain, improved functional outcomes, corrected KA and restored CR after operation, but no difference was found between two groups. CONCLUSIONS: Our findings suggest that percutaneous kyphoplasty is an effective and safe procedure for patients with secondary single segmental osteoporotic vertebral compression fractures; it can achieve similar clinical outcomes to the primary osteoporotic vertebral compression fractures.

Transmuscular Ultrasonography of the Placement of Thoracolumbar Pedicle Screws: A Cadaveric Study.

BACKGROUND: Transpedicular screw fixation has a biomechanical advantage of improving fusion rates. In posterior thoracolumbar immobilization, a large number of screws cause perforation to the pedicle or vertebral body. Radiography and computed tomography (CT) have been used to minimize this complication. The ability of ultrasound (US) to detect the pedicle breach during placement of the screw is unknown. The aim of this study was to evaluate the sensitivity of US for detecting breaches. METHODS: A B-type transducer was used to scan 216 titanium pins inserted into cadaveric pedicles. Of the pins, 180 were intentionally misplaced: 90 pins breached the lateral wall of the pedicle, and 90 pins pierced the anterior wall of the vertebral body. US images were reviewed by 3 examiners blinded to both the procedure and the corresponding CT findings. The perforation length of pins was measured by 3 radiologists on CT images. RESULTS: CT data were divided into 2 groups. In group 1 (perforation length 0-2 mm), sensitivity of US for detecting lateral wall and anterior wall perforation was 80.95% and 76.42%, respectively; in group 2 (perforation length 2-4 mm), sensitivity was 94.79% and 91.93%. Overall sensitivity of US to detect lateral wall and anterior wall perforation was 89.63% and 86.30%, respectively. The sensitivity of US for detecting perforation was greater in the lateral wall than in the anterior wall. Sensitivity of US was greater in group 2 than group 1 for both lateral and anterior perforation. CONCLUSIONS: US can be applied to detect perforation of ≤4 mm. Use of US may improve patient safety.

Comparison of the more than 5-year clinical outcomes of cervical disc arthroplasty versus anterior cervical discectomy and fusion: A protocol for a systematic review and meta-analysis of prospective randomized controlled trials.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) was almost the "golden standard" technique in treatment of symptomatic cervical degenerative disc disease, however, it cause motion loss of the indexed level, increase the intradiscal pressure and motion of the adjacent levels, and may accelerate the degeneration of adjacent level. Cervical disc arthroplasty (CDA) was designed to preserve the motion of index level, avoid the over-activity of adjacent levels and reduce the degeneration of adjacent disc levels, the process of degeneration of adjacent level is very slowly, long term follow up studies should be conducted, this study aim to compare the more than 5 years' long-term clinical outcomes and safety between CDA and ACDF. METHODS: A systematic review and meta-analysis that will be performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The electric database of Medline, Embase, and Cochrane library will be systematic search. A standard data form will be used to extract the data of included studies. We will assess the studies according to the Cochrane Handbook for Systematic Reviews of Interventions, and perform analysis in software STATA 12.0. Fixed-effects models will be used for homogeneity data, while random-effects will be used for heterogeneity data. The overall effect sizes will be determined as weighted mean difference (WMD) for continuous outcomes and Relative risk (RR) for dichotomous outcomes. RESULTS: The results of study will be disseminated via both international conference and peer-review journal. CONCLUSION: The conclusion of our study will provide the long-term and updated evidence of clinical outcomes and safety between CDA and ACDF, and help surgeon to change better surgical technique for patients.

The relationship between dietary protein consumption and risk of fracture: a subgroup and dose-response meta-analysis of prospective cohort studies.

It is still debate of the relationship between the dietary protein consumption and risk of fracture. We searched Medline and Embase to assess the effects of dietary protein consumption on risk of fracture. Twelve prospective cohort studies with 407,104 participants were included, higher total protein consumption may be decrease 11% risk of hip fractures, with adj. RR of 0.89 (0.82, 0.97), no significant difference was found for total protein and risk of all fractures and limb fracture; for animal protein consumption and risk of all fractures and hip fracture, with adj.RR of 0.79 (032, 1.96) and 1.04 (0.70, 1.54); for vegetable protein consumption and risk of all fractures, hip fracture and limb fractures with adj.RR of 0.77 (0.52, 1.12), 1.00 (0.53, 1.91), and 0.94 (0.40, 2.22), the subgroup of vegetable protein consumption and risk of all fractures of postmenopausal women with adj.RR of 0.78(0.52,1.16). Dose-response meta-analysis the relationship of total/animal/vegetable protein and hip fracture was consistent to the results of forest plot, the line of total protein and hip fracture was below the Y = 1.0 line. This meta-analysis showed that total dietary protein consumption may be decrease the risk of hip fracture, but not for animal or vegetable protein.

The existence of intravertebral cleft impact on outcomes of nonacute osteoporotic vertebral compression fractures patients treated by percutaneous kyphoplasty: a comparative study.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: The purpose of this study is to assess radiologic features of intravertebral cleft (IVC) in nonacute osteoporotic vertebral compression fractures (OVCFs) patients, and analyze the existence of IVC impact on outcomes of percutaneous kyphoplasty (PKP). SUMMARY OF BACKGROUND DATA: The IVC sign is regarded as vertebral instability and the cause of persisting pain. It is more likely to happen at nonacute OVCFs patients. Patients with IVC sign have different outcomes from these without IVC treated by percutaneous vertebroplasty. There were rare reports about the outcomes of patients with IVC sign treated by PKP. MATERIALS AND METHODS: We divided 92 nonacute OVCFs patients (total of 113 vertebrae) into 2 groups according to the existence of IVC. Preoperative and postoperative Visual Analogue Scales, Oswestry Disability Index, kyphotic angulation (KA), and anterior vertebral height were recorded; the incidence and radiologic features of IVC were analyzed. RESULTS: The diagnostic sensitivity of IVC on plain radiograph, computed tomography, and magnetic resonance imaging were 35.4%, 89.3%, and 83.3%, respectively. The IVC group had an average correction KA of 9.14 degrees and reduction of ratio of compression of 20.09%, and the non-IVC group was 8.76 degrees and 20.23%, respectively. Cleft pattern of cement accounted for 64.6% in IVC group and 27.7% in non-IVC group. Five/7 of cement leakage in IVC group was intradiscal leakage, whereas 7/9 of cement leakage in non-IVC group was perivertebral leakage. CONCLUSIONS: Computed tomography and magnetic resonance imaging were more sensitivity to diagnose IVC sign than X-ray. PKP could improve pain, functional activity, KA, and anterior height of both IVC and non-IVC groups, however, there was more cleft pattern of cement and higher intradiscal cement leakage in the IVC group.

[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.

[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.

[Application of anterior percutaneous screw fixation in treatment of odontoid process fractures in aged people].

OBJECTIVE: To explore the efficacy of anterior percutaneous screw fixation in the treatment of odontoid process fractures in aged people. METHODS: From February 2001 to April 2009, 15 elderly patients with odontoid fracture were treated with anterior percutaneous screw fixation,including 13 males and 2 females; the average age was 69.3 years (ranged, 60 to 86 years). According to Anderson classification, there were 10 patients with type II fractures (type II A in 7 cases, type II B in 3 cases, based on Eysel and Roosen classification), 4 patients with shallow type III fractures, 1 patient with deep type III fractures. Thirteen patients were fresh fractures, 2 patients were obsolete fractures. All patients had varying degrees of neck or shoulder pain, and limit activity of neck. There were 4 patients with neural symptoms including 2 grade D and 2 grade C according to Frankel classification. All the patients were followed up and were assessed by radiology. Clinical examination included neck activity, neurological function and the degree of neck pain. Radiology examinations including anteroposterior, lateral, open mouth position and flexion-extension radiographs of cervical vertebra were performed. RESULTS: After surgery, all patients were followed up,and the duration ranged from 6 to 60 months (averaged 31.3 months). Two patients died of other diseases during the follow-up period (18 and 22 months after surgery respectively). All patients got satisfactory results, and all screws were in good position. As the screw was too long, esophagus was compressed by screw tail in one case. One case showed fibrous union, 12 cases had achieved solid bony union, 2 cases showed nonunion without clinical symptoms. The rotation of neck in 3 cases was mildly limited,the neck function of the remaining patients were normal. Four patients with symptoms nerve injuries improved after operation (Frankel E in 3 cases, Frankel D in 1 case). The symptom of neck pain had a significant improvement after surgery (P < 0.001). The VAS score decreased from preoperative (6.07 +/- 1.44) (4 to 8 scores),to postoperative (1.13 +/- 0.92) (0 to 3 scores). And there were no severe postoperative complications. CONCLUSION: The anterior percutaneous screw fixation is less traumatic than conventional approaches for aged people in dealing with odontoid process fractures. Most patients will achieve satisfactory clinical results, as long as the general conditions of them are comprehensively assess. However, this procedure should not be used in patients with comminuted odontoid fractures or severe osteoporosis.

[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.

Pedicle screw insertion accuracy with different assisted methods: a systematic review and meta-analysis of comparative studies.

Studies revealed that navigation systems that provided intraoperative assistance might improve pedicle screw insertion accuracy, and also implied that different systems provided different pedicle screw insertion accuracy. A systematic review and meta-analysis was conducted to focus on the pedicle screw insertion accuracy with or without the assistance of image-guided system, and the variance among the different navigation systems. Comparative studies were searched on pedicle screw insertion accuracy between conventional and navigated method, and among different navigation systems. A total of 43 papers, including 28 clinical, 14 cadaveric and 1 model studies, were included in the current study. For clinical articles, there were 3 randomized clinical trials, 4 prospective comparative studies and 21 retrospective comparative studies. The incidence of pedicle violation among computer tomography-based navigation method group was statistically significantly less than that observed among the conventional group (OR 95% CI, in vivo: 0.32-0.60; in vitro: 0.24-0.75 P < 0.01). Two-dimensional fluoroscopy-based navigation system (OR 95% CI, in vivo: 0.27-0.48; in vitro: 0.43-0.88 P < 0.01) and three-dimension fluoroscopy-based navigation system (OR 95% CI, in vivo: 0.09-0.38; in vitro: 0.09-0.36 P < 0.01) also obtained significant reduced screw deviation rate over traditional methods. Between navigated approaches, statistically insignificant individual and pooled RR values were observed for all in vivo subgroups. Pooled estimate of in vitro studies show that computer tomography-based and three-dimension fluoroscopy-based navigation system provided more accurate pedicle screw insertion over two-dimension fluoroscopy-based navigation system. Our review showed that navigation provided a higher accuracy in the placement of pedicle screws compared with conventional methods. The superiority of navigation systems was obvious when they were applied to abnormal spinal structure. Although no strong in vivo evidence has detected significantly different pedicle screw placement accuracy among the three major navigation systems, meta-analysis revealed the variance in pedicle screw insertion accuracy with different navigation methods.

[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.

[Mid-term outcomes of minimally invasive transforaminal lumbar interbody fusion with unilateral pedicle screw fixation for lower lumbar degenerative diseases].

OBJECTIVE: To evaluate the mid-term clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (TLIF) with unilateral pedicle screw fixation for lower lumbar degenerative diseases. METHODS: From April 2004 to December 2005, minimally invasive TLIF through paramedian approach with unilateral pedicle screw fixation was performed in a consecutive series of 43 patients, including 24 male and 19 female, aging from 38 to 71 years, with an average age of 49 years. The length of surgical incision was 3 cm. The operation level at L(3-4) were 3 cases, L(4-5) 27 cases, L(5)-S(1) 13 cases and no case was at multilevel. Clinical outcomes were assessed by ODI scores and JOA questionnaires before and after operation. Operation time, intraoperative blood loss, incision status and complications were recorded. Radiological examination was obtained for each patient to assess the height of intervertebral space, postoperative intervertebral fusion conditions and the degeneration of adjacent segments. RESULTS: The mean operation time was 110 minutes, the mean blood loss was 150 ml and all the incisions were healed primarily. The follow-up time ranged from 36 to 58 months. The ODI scores decreased significantly from 60 ± 10 preoperatively to 12 ± 4 postoperatively (P < 0.01). The JOA scores were improved remarkably from 9.6 ± 2.2 preoperatively to 23.8 ± 2.0 postoperatively (P < 0.01) and the proportion with optimal effect was 86%. The ventral and dorsal heights of intervertebral disc were significantly higher than those before operation (P < 0.01). The fusion rate was 94%. The incidence of adjacent segment degeneration was 17%. There were no complications such as secondary scoliosis, screw loosening, internal fixation failure and cage slippage. CONCLUSIONS: The minimally invasive TLIF through paramedian approach with unilateral pedicle screw fixation is an effective and convenient method with little surgical trauma. The mid-term follow up results showed favorable outcomes in patients receiving this surgery.

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.