Wright's Technique with the Addition of Visualized Axial Cortical Windows in Odontoid Fractures

This study sought to investigate and evaluate a modified axial translaminar screw fixation for treating odontoid fractures. We performed a retrospective study at Wenzhou Medical University Affiliated Second Hospital between March 2016 and June 2018. We retrospectively collected and analyzed the medical records of 23 cases with odontoid fractures. All patients were identified as type II odontoid fractures without neurological deficiency and serious diseases following the classification of Anderson. The average age, gender ratio, and body mass index (BMI) were 54.3 ± 11.1 years, 12 men to 11 women, and 22.6 ± 2.4 kg/m² , respectively. Patients in this study accepted screw fixation using our modified axial translaminar screw fixation combined with atlas pedicle or lateral mass screw fixation. Within the technique, a small cortical "window" was dug in the middle of the axial contralateral lamina, such that the screws in the lamina were visualized to prevent incorrectly implanting the posterior spinal canal through the visualized "window." A total of 46 bone screws were accurately inserted into the axial lamina without using fluoroscopy. The length of all translaminar screws ranged between 26 and 30 mm, while the diameter was 3.5 mm. During the follow-up survey, the visual analog scale (VAS) and neck disability index (NDI) were measured. We provide a simple modification of Wright's elegant technique with the addition of "visualized windows" at the middle of the axial lamina. In all patients, screws were inserted accurately without bony breach and the screw angle was 56.1 ± 3.0°. Mean operative time was 102 ± 28 min with an average blood loss of 50 ± 25 mL. Postoperative hemoglobin and mean length of hospital stay were 12.0 ± 1.4 g/dL and 10.4 ± 3.4 days, respectively. The average follow-up time of all cases was 14.7 months and no internal fixation displacement, loosening, or breakage was found. All patients with odontoid fractures reported being satisfied with the treatment during the recheck period and good clinical outcomes were observed. At 1, 6, and 12 months, NDI and VAS showed that the symptoms of neck pain and limitations of functional disability improved significantly during follow-up. Our results suggest that the modified translaminar screw fixation technique can efficiently treat Anderson type II odontoid fracture, followed by the benefits of less soft tissue dissection, simple operation, no fluoroscopy, and accurate placement of screws.

Alcohol intake and the risk of chronic kidney disease: results from a systematic review and dose-response meta-analysis

Many prospective cohort studies have investigated the association between the consumption of alcohol and CKD risk and have revealed inconsistent results. In the present study, we aimed to perform a meta-analysis of these studies to assess this association.We searched the PubMed and Embase databases up to 2020 and reviewed the reference lists of relevant articles to identify appropriate studies. We calculated the pooled relative risks with 95% CIs using random effects models, and then performed subgroup and meta-regression analyses. Dose-response meta-analyses were performed by sex separately. We identified 25 eligible prospective cohort studies, including 514,148 participants and 35,585 incident CKD cases. Compared with the category of minimal alcohol intake, light (RR = 0.90, I2 = 49%), moderate (RR = 0.86, I2 = 40%), and heavy (RR = 0.85, I2 = 51%) alcohol intake were associated with a lower risk of CKD. Subgroup meta-analysis by sex indicated that light (RR = 0.92, I2 = 0%), moderate (RR = 0.83, I2 = 39%) and heavy (RR = 0.76, I2 = 40%), alcohol consumption were inversely associated with CKD risk in male. Dose-response meta-analyses detected a nonlinear inverse association between alcohol consumption and the risk of CKD in all participants and linear inverse association in female participants. This meta-analysis shows that light (<12 g/day), moderate (12-24 g/day), and heavy (>24 g/day) alcohol consumption are protective against chronic kidney disease in adult participants especially in males.

[Screening of phenylketonuria and analysis of phenylalanine hydroxylase gene in 380 996 newborns from Hainan province]

Objective: To investigate the incidence of phenylketonuria and distribution characteristics of phenylalanine hydroxylase (PAH) gene in newborns from Hainan province. Methods: Dry blood spot specimens of heels from 380 996 newborns in Hainan province from January 2017 to December 2019 were collected. Phenylalanine (Phe) concentrations in these dry blood spots were measured by the fluorescence method to screen phenylketonuria (PKU). A second dry blood spot sample will be collected if suspicious samples were detected after initial screening. Tandem mass spectrometry were used to detect the concentrations of Phe and tyrosine. Urine samples of the suspected newborns were sent out for urotrexate spectrum analysis and tetrahydrobiopterin loading test. PCR and flow-through rapid hybridization method were employed to detect PAH gene mutations. Meanwhile, peripheral blood samples of suspicious newborns of PKU and their parents were collected to perform gene sequencing. Results: Among the 380 996 newborns, 39 were suspected and 14 were diagnosed with PKU, including 11 cases of PAH deficiency and 3 cases of tetrahydrobiopterin deficiency. Of 14 confirmed cases, there were 8 male cases and 6 female cases. In the newborn population of Hainan province, the annual incidence of PKU was 1.22/100 000. Thirteen PAH gene mutations were detected in confirmed cases: c.728G>A, c.158G>A, c.1238G>C, c.611A>G, c.1068C>A, c.706+5G>A, c.740G>T, c.1081A>T, c.793T>G, c.1223G>A, c.721C>T, c.331C>T and c.1174T>A. Conclusions: PKU has a high incidence in newborn population of Hainan province in the past three years. The PAH gene has a wide spectrum of mutations. Two rare mutations were also found: c.793T>G and c.706+5G>A.

Association of osteoarthritis and circulating adiponectin levels: a systematic review and meta-analysis

BACKGROUND

The objective of this study was to perform a meta-analysis to investigate the specific relationship between the expression level of circulating adiponectin and osteoarthritis (OA).

METHOD

Multiple databases were searched to estimate the high quality of studies relevant to adiponectin and OA. We extracted the data from the eligible studies and included them in the meta-analysis using a random effects model. Subgroup analysis and meta-regression were further performed to explore the potential sources of heterogeneity.

RESULTS

Ten articles consisting of thirteen case-control studies that contained a combined total of 1255 subjects. Our results revealed that the OA patients displayed higher adiponectin levels than the healthy controls (SMD = 0.327, 95% CI: 0.11-0.55, P = 0.003). The ethnicity-stratified subgroup analysis indicated that the adiponectin was a sensitive biomarker in both Caucasians (P = 0.021) and Asians (P = 0.037). Moreover, the meta-regression analysis suggested that the sample size (P = 0.03) and nationality (p = 0.01) could account for a part of heterogeneity in our study.

CONCLUSION

Taken together, the current study indicated that the adiponectin expression levels were higher in the OA patients than in the healthy controls and might be associated with OA prevalence.

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.

Cervical digit in a child: A case report

BACKGROUND

A "digit-like" bone is a rare developmental anomaly that is usually seen in the pelvic or thoracic regions. Such an anomaly in the cervical spine is extremely rare and few cases have been reported. We present a patient with an anomalous bone posterior to a cervical vertebra. The patient was admitted to our hospital with a gradually growing hard neck mass and esthetic complaints. Physical examination, radiographs, reconstructed computed tomography, and magnetic resonance imaging revealed a digit-like bone posterior to the cervical spine. The patient was diagnosed with a "cervical digit." Through a posterior midline approach, the anomalous bone was excised because of its gradually increasing size and esthetic complaints.

RESULTS

Intraoperatively, the bony mass was found to have a pseudoarticulation with the spinous process of C5 (the fifth cervical vertebra). The specimen consisted of normal bone and cartilage. The child returned to a normal life postoperatively with no symptoms. There was no recurrence at the 2-year follow-up.

CONCLUSION

A congenital cervical digit is a rare deformity. A detailed clinical workup and advanced imaging examinations are useful for diagnosing such conditions. Esthetic complaints contribute to surgical indications. This is the first cervical digit managed with surgical excision of the anomalous bone and had a favorable outcome.

Selective medial soft tissue release combined with tibial reduction osteotomy in total knee arthroplasty

BACKGROUND

To obtain the correct coronal alignment and balancing in flexion and extension, we established a selective medial release technique and investigated the effectiveness and safety of the technique during primary total knee arthroplasty (TKA).

METHODS

Four hundred sixty-six primary TKAs with varus deformity were prospectively evaluated between June 2013 and June 2015. A knee joint position similar to Patrick's sign was used to release the medial structure. The medial release technique consisted of release of the capsule and the deep medial collateral ligament (dMCL) (step1), selective release of superficial medial collateral ligament (sMCL) or posterior oblique ligament (POL) (step 2), and selective tibial reduction osteotomy (step 3). Improvement of medial joint gap at each step and other clinical outcomes were evaluated.

RESULTS

Among the 466 knees, symmetrical gaps could be achieved by the limited release of the capsule and the dMCcL in 276 (59%) knees. One hundred fifty-two (33%) required additional sMCL release with 2-5 cm from the joint line distally or POL release. Thirty-eight (8%) necessitated an additional tibial reduction osteotomy. Anterior-medial release and 4-mm medial osteotomy contributed to more improvement of medial gap in flexion than in extension (each p < 0.01). Posteromedial release and posteromedial osteotomy contributed to more improvement in extension than in flexion (each p < 0.01). No specific complication related to our technique was identified.

CONCLUSION

The technique of the tibial reduction osteotomy combined with medial soft structure release using Patrick's sign is effective, safe, and minimally invasive to obtain balanced mediolateral and extension-flexion gaps in primary TKA.

[Clinical efficacy of unilateral percutaneous transfacet screws combined with contralateral pedicle screw versus bilateral pedicle screws fixation in the treatment of the degenerative lumbar disease]

OBJECTIVE

To investigate the surgical outcome of unilateral pedicle screw(UPS) after TLIF technique combined with contralateral percutaneous transfacet screw(PTS) fixation vs bilateral pedicle screws(BPS) fixation in treatment of degenerative lumbar disease.

METHODS

From January 2009 to June 2012, 46 patients with degenerative lumbar diseases, including 30 males and 16 females with an average age of 51.5 years old, who were divided into two groups according to different fixation methods. Twenty-two cases underwent UPS after TLIF technique combined with contralateral PTS fixation (group A), while the others underwent BPS fixation(group B). The relative data were analyzed, such as blood loss volume, operative time, fusion rate, ODI score, JOA score and so on.

RESULTS

All the patients were followed up for 1 to 3 years with an average of 22 months. Except one case of each group was uncertainty fusion, the rest have obtained bony fusion, and the fusion rates in group A and B were 95.5% and 95.8%, respectively. No displacement and breakage of screw were found during follow-up. Operative time and blood loss volume in group A were better than of group B(P<0.05). ODI and JOA scores had improved obviously than preoperation(P<0.05), but the differences had no statistical significance between two groups(P>0.05).

CONCLUSIONS

Two approaches had similar clinical outcomes for degenerative lumbar disease with no severe instability. Compared with BPS fixation, the UPS after TLIF technique and contralateral PTS fixation has the advantages of less trauma, shorter operative time and less blood loss, and it is a safe and feasible surgical technique.

Dl-3-n-butylphthalide attenuates acute inflammatory activation in rats with spinal cord injury by inhibiting microglial TLR4/NF-κB signalling

In this study, we examined the neuroprotective effects and anti-inflammatory properties of Dl-3-n-butylphthalide (NBP) in Sprague-Dawley (SD) rats following traumatic spinal cord injury (SCI) as well as microglia activation and inflammatory response both in vivo and in vitro. Our results showed that NBP improved the locomotor recovery of SD rats after SCI an significantly diminished the lesion cavity area of the spinal cord, apoptotic activity in neurons, and the number of TUNEL-positive cells at 7 days post-injury. NBP inhibited activation of microglia, diminished the release of inflammatory mediators, and reduced the upregulation of microglial TLR4/NF-κB expression at 1 day post-injury. In a co-culture system with BV-2 cells and PC12 cells, NBP significantly reduced the cytotoxicity of BV-2 cells following lipopolysaccharide (LPS) stimulation. In addition, NBP reduced the activation of BV-2 cells, diminished the release of inflammatory mediators, and inhibited microglial TLR4/NF-κB expression in BV-2 cells. Our findings demonstrate that NBP may have neuroprotective and anti-inflammatory properties in the treatment of SCI by inhibiting the activation of microglia via TLR4/NF-κB signalling.

Extramedullary versus intramedullary femoral alignment technique in total knee arthroplasty: a meta-analysis of randomized controlled trials

BACKGROUND

There is no consensus whether the use of the extramedullary femoral cutting guide takes advantage over the intramedullary one in total knee arthroplasty. The aim of this study was to compare the extramedullary femoral alignment guide system with the conventional intramedullary alignment guide system for lower limb alignment, blood loss, and operative time during total knee arthroplasty.

METHODS

The Medline, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang Chinese Periodical, Google, and reference lists of all the included studies were searched for randomized controlled trials. The following parameters were compared between the extramedullary technique and the intramedullary technique: (1) lower limb coronal alignment, (2) coronal alignment of femoral component, (3) sagittal alignment of femoral component, (4) blood loss, (5) and operation time.

RESULTS

Four randomized controlled trials consisting of 358 knees were included in our study. There was no significant difference between the extramedullary and intramedullary groups for the lower limb coronal alignment (RR = 1.20, 95%CI 0.28~5.21, n.s.), coronal alignment of femoral component (RR = 0.65, 95%CI 0.19~2.22, n.s.), and sagittal alignment of femoral component (RR = 0.73, 95%CI 0.38~1.41, n.s.). A reduced blood loss was associated with the use of the extramedullary guide (MD = -120.34, 95%CI -210.08~-30.59, P = 0.009). No significant difference in operation time was noted between the two groups (MD = 1.41, 95%CI -1.82~4.64, n.s.).

CONCLUSIONS

Neither extramedullary nor intramedullary femoral alignment is more accurate than the other in facilitating the femoral cut in total knee arthroplasty. Use of the extramedullary guide results in less blood loss and exhibits a similar operation time as compared with the intramedullary guide.

The Spinal Cord Line Can Predict Postoperative Recovery for Multilevel Cervical Spondylotic Myelopathy

OBJECTIVE

To report a new index, the spinal cord (SC) line, and a new classification to predict postoperative recovery effect in patients with multilevel cervical spondylotic myelopathy (CSM).

METHODS

On T2-weighted magnetic resonance imaging (MRI) of the cervical spine, point A is the posteroinferior point of the spinal cord at C2, and point B is the posterosuperior point of the spinal cord at C7. The SC line is defined as a line connecting A and B. The posterior surface of the compressor at the compression level does not exceed the line in SC line type I, touches the line in type II, and exceeds the line in type III. Between January 2010 and January 2015, 121 patients with multilevel CSM who underwent surgery through an anterior approach (anterior cervical corpectomy with fusion or anterior cervical discectomy and fusion) or a posterior approach (laminoplasty or laminectomy) in our hospital were studied retrospectively. The patients were classified into 3 groups according to SC line type (I, II, or III).

RESULTS

In the anterior surgical approach group, the Japanese Orthopaedic Association (JOA) recovery rate at the last follow-up was 84.88 ± 3.06% for SC line type I, 78.05 ± 2.89% for type II, and 68.69 ± 3.21% for type III. In the posterior surgical approach group, the JOA recovery rate at last follow-up was 69.35 ± 8.73% for type I, 58.05 ± 5.88% for type II, and 47.98 ± 4.31% for type III. The anterior surgery approach was associated with a higher postoperative recovery rate than the posterior surgery approach in type II and type III groups (type II anterior vs. type II posterior: 78.05 ± 2.89% vs. 58.05 ± 5.88%, P = 0.003; type III anterior vs. type III posterior: 68.69 ± 3.21% vs. 47.98 ± 4.31%, P = 0.001). In contrast, the anterior and posterior surgery were associated with similar postoperative recovery rates in the type I group (84.88 ± 3.06% vs. 69.35 ± 8.73%; P = 0.820).

CONCLUSIONS

The SC line and its classifications can predict postoperative recovery in patients with multilevel CSM.

An ultrastructural study of chondroptosis: programmed cell death in degenerative intervertebral discs in vivo

Apoptosis has been regarded to mediate intervertebral disc degeneration (IDD); however, the basic question of how the apoptotic bodies are cleared in the avascular intervertebral disc without phagocytes, which are essential to apoptosis, remains to be elucidated. Our goals were to investigate the ultrastructure of nucleus pulposus (NP) cells undergoing chondroptosis, a variant of apoptotic cell death, in a rabbit annular needle-puncture model of IDD. Experimental IDD was induced by puncturing discs with a 16-G needle in New Zealand rabbits. At 4 and 12 weeks after puncture, progressive degeneration was demonstrated by X-ray, magnetic resonance imaging and histological staining. TUNEL staining suggested a significant increase in the apoptosis index in the degenerated NP. However, the percentage of apoptotic cells with the classic ultrastructure morphology was much less than that with chondroptotic ultrastructure morphology under transmission electron microscopy (TEM). The chondroptotic cells from the early to late stage were visualized under TEM. In addition, the percentage of chondroptotic cells was significantly enhanced in the degenerated NP. Furthermore, 'paralyzed' cells were found in the herniated tissue. Western blotting revealed an increase in caspase3 expression in the degenerated NP. The expression of the Golgi protein (58K) was increased by the fourth week after puncture but decreased later. These findings indicate that chondroptosis is a major type of programmed cell death in the degenerated rabbit NP that may be related to the progressive development of IDD.

Long fusion correction of degenerative adult spinal deformity and the selection of the upper or lower thoracic region as the site of proximal instrumentation: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to compare outcomes when the upper and lower thoracic regions were used as the site of proximal instrumentation to treat adult spinal deformity.

METHODS

MEDLINE, Embase and Cochrane library searches were performed to identify studies that compared outcome measures when the upper and lower thoracic vertebrae (UTV and LTV, respectively) were used as the site of proximal instrumentation. The weighted mean difference (WMD) was calculated for continuous outcomes, and the relative risk (RR) was calculated for dichotomous outcomes.

RESULTS

Seven articles (n=554 patients) met the final inclusion criteria, and we compared the outcome measures of a long fusion extending to the upper and lower thoracic regions. The pooled analysis revealed that extending fixation into the upper thoracic region decreased the risk of proximal junctional kyphosis (PJK) revision surgery (RR: 0.36, 95% CI 0.14 to 0.90, p<0.05). The operation time (WMD: 0.93, 95% CI 0.48 to 1.39, p<0.05) and estimated blood loss (WMD: 0.59, 95% CI 0.33 to 0.85, p<0.05) were significantly greater in the UTV group than in the LTV group. No significant differences were found in the Scoliosis Research Society pain, self-image, function, mental health, subtotal, satisfaction or total scores; the total number of complications or the total number of revision surgeries.

CONCLUSIONS

Long posterior fixation extending into the upper thoracic region reduces the incidence of revision surgery related to PJK; however, it increased the operative level resulting in a longer operative time and greater estimated blood loss. This initial analysis indicates that extending fixation to the upper thoracic region is appropriate for patients who are likely to develop PJK following initial scoliosis correction.

Regulation of Caveolin-1 and Junction Proteins by bFGF Contributes to the Integrity of Blood-Spinal Cord Barrier and Functional Recovery

The blood-spinal cord barrier (BSCB) plays important roles in the recovery of spinal cord injury (SCI), and caveolin-1 is essential for the integrity and permeability of barriers. Basic fibroblast growth factor (bFGF) is an important neuroprotective protein and contributes to the survival of neuronal cells. This study was designed to investigate whether bFGF is beneficial for the maintenance of junction proteins and the integrity of the BSCB to identify the relations with caveolin-1 regulation. We examined the integrity of the BSCB with Evans blue dye and fluorescein isothiocyanate-dextran extravasation, measured the junction proteins and matrix metalloproteinases, and evaluated the locomotor function recovery. Our data indicated that bFGF treatment improved the recovery of BSCB and functional locomotion in contusive SCI model rats, reduced the expression and activation of matrix metalloproteinase-9, and increased the expressions of caveolin-1 and junction proteins, including occludin, claudin-5, p120-catenin, and β-catenin. In the brain, in microvascular endothelial cells, bFGF treatment increased the levels of junction proteins, caveolin-1 small interfering RNA abolished the protective effect of bFGF under oxygen-glucose deprivation conditions, and the expression of fibroblast growth factor receptor 1 and co-localization with caveolin-1 decreased significantly, which could not be reversed by bFGF treatment. These findings provide a novel mechanism underlying the beneficial effects of bFGF on the BSCB and recovery of SCI, especially the regulation of caveolin-1.

Correlative study between the JAK2V617F mutation and thrombosis in patients with myeloproliferative neoplasm

In this study, we investigated the correlation between the JAK2V617F mutation and thrombosis in patients with myeloproliferative neoplasm (MPN) using real-time fluorescence quantitative PCR. The incidence of thrombus was monitored and blood and coagulation were routinely assayed in patients with MPN. The JAK2V617F mutation was found in 8/68 individuals in the control group (11.8%); it was expressed in 44/68 patients with MPN (64.7%), suggesting that the rate of this mutation was significantly higher in patients with MPN than that in the control group. Twenty-six MPN patients (38.2%) showed symptoms of thrombosis; MPN patients with thrombosis showed a significantly higher rate of the JAK2V617F mutation, were of a greater age, and had higher blood pressure than MPN patients without thrombosis. In addition, the white blood cells (WBC) (21.98 ± 1.95) and platelets (364.68 ± 97.72) were significantly higher in patients, expressing the mutated gene, with polycythemia vera than in the patients without the mutation. The WBC (32.89 ± 4.25) and hemoglobin (161.92 ± 16.19) were significantly increased in the essential thrombocythemia patients with gene mutation compared with the patients without mutation. MPN patients showed higher blood clotting ability than the control subjects; moreover, MPN patients with the JAK2V617F mutation showed higher blood clotting ability than those without the mutation. The findings of this study indicate that the JAK2V617F mutation is correlated with the incidence of thrombosis, and analysis of this mutation has important clinical significance in the diagnosis and treatment of MPN.

Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw and Contralateral Percutaneous Transfacet Screw Fixation for the Treatment of Lumbar Degenerative Disorders

AIM

To assess the feasibility and efficacy of TLIF with unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation for the treatment of lumbar degenerative disorders.

MATERIAL AND METHODS

A series of computed tomography (CT) digital images from 60 patients (30 males and 30 females) with L3-S1 segments, were reconstructed in three dimensions using a software named Xelis 3D. Linear and angular measurements of the facets were recorded. Fifty-six patients were divided to either bilateral pedicle screw fixation (BPS) (n=30) or unilateral pedicle screw and contralateral percutaneous transfacet screw fixation (UPFS) (n=26) groups. The operating time, blood loss, length of hospital stay, clinical outcomes, fusion and complication rates were compared between the two groups.

RESULTS

The parameters of the facets we recorded were no significant differences between the left and right sides (p > 0.05). No statistically significant differences between males and females were observed, except the maximum width of superior facet at L4 and S1, and length of screw at all levels. Intraoperative parameters, such as operating time, blood loss and postoperative hospital stay had significantly larger in the BPS group than UPFS group (p < 0.05). No significant differences were found between the two groups in clinical results, fusion and complication rates (p > 0.05).

CONCLUSION

Because of the similar clinical outcomes but less operative time, blood loss and length of postoperatively hospital stay, unilateral pedicle screw and contralateral percutaneous lumbar transfacet screw fixation might be an attractive technique compared to bilateral pedicle screw fixation for treating lumbar degenerative disorders with TLIF. Nevertheless differences of the anatomical parameters for the lumbosacral facets fixation between Chinese and Westerners should be noted.

A novel computed method to reconstruct the bilateral digital interarticular channel of atlas and its use on the anterior upper cervical screw fixation

Purpose. To investigate a novel computed method to reconstruct the bilateral digital interarticular channel of atlas and its potential use on the anterior upper cervical screw fixation.

Methods. We have used the reverse engineering software (image-processing software and computer-aided design software) to create the approximate and optimal digital interarticular channel of atlas for 60 participants. Angles of channels, diameters of inscribed circles, long and short axes of ellipses were measured and recorded, and gender-specific analysis was also performed.

Results. The channels provided sufficient space for one or two screws, and the parameters of channels are described. While the channels of females were smaller than that of males, no significant difference of angles between males and females were observed.

Conclusion. Our study demonstrates the radiological features of approximate digital interarticular channels, optimal digital interarticular channels of atlas, and provides the reference trajectory of anterior transarticular screws and anterior occiput-to-axis screws. Additionally, we provide a protocol that can help make a pre-operative plan for accurate placement of anterior transarticular screws and anterior occiput-to-axis screws.

Percutaneous atlantoaxial anterior transarticular screw fixation combined with mini-open posterior C1/2 wire fusion for patients with a high-riding vertebral artery

CONTEXT/OBJECTIVE

To describe the technique and clinical results of percutaneous atlantoaxial anterior transarticular fixation combined with limited exposure posterior C1/2 arthrodesis in patients with a high-riding vertebral artery.

DESIGN SETTING

Zhejiang Spine Center, China.

PARTICIPANTS

Five patients with a high-riding vertebral artery and an upper cervical fracture.

INTERVENTIONS

Percutaneous atlantoaxial anterior transarticular screw fixation combined with limited exposure posterior C1/2 wire fusion.

OUTCOME MEASURES

Computed tomography scans were used to assess the high-riding vertebral artery and feasibility of anterior transarticular screw fixation preoperatively. A Philadelphia collar was used to immobilize the neck postoperatively. Anteroposterior (open-mouth) and lateral views were obtained at pre/postoperation and at the follow-up.

RESULTS

The operation was performed successfully on all of the patients, and no intraoperative operation-related complications such as nerve injury, vertebral artery, and soft tissue complications occurred. The mean follow-up period was 33.8 months (range: 24 to 58 months). No screw breakage, loosening, pullout, or cutout was observed. Bone union was achieved in all patients at the last follow-up.

CONCLUSIONS

Our small case series results suggested that percutaneous anterior transarticular screw fixation combined with mini-open posterior C1/2 wire fusion is a technically minimally invasive, safe, feasible, and useful method to treat patients with a high-riding vertebral artery.

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.

Retinoic Acid Induced-Autophagic Flux Inhibits ER-Stress Dependent Apoptosis and Prevents Disruption of Blood-Spinal Cord Barrier after Spinal Cord Injury

Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB) which leads to infiltration of blood cells, an inflammatory response, and neuronal cell death, resulting spinal cord secondary damage. Retinoic acid (RA) has a neuroprotective effect in both ischemic brain injury and SCI, however the relationship between BSCB disruption and RA in SCI is still unclear. In this study, we demonstrated that autophagy and ER stress are involved in the protective effect of RA on the BSCB. RA attenuated BSCB permeability and decreased the loss of tight junction (TJ) molecules such as P120, β-catenin, Occludin and Claudin5 after injury in vivo as well as in Brain Microvascular Endothelial Cells (BMECs). Moreover, RA administration improved functional recovery in the rat model of SCI. RA inhibited the expression of CHOP and caspase-12 by induction of autophagic flux. However, RA had no significant effect on protein expression of GRP78 and PDI. Furthermore, combining RA with the autophagy inhibitor chloroquine (CQ) partially abolished its protective effect on the BSCB via exacerbated ER stress and subsequent loss of tight junctions. Taken together, the neuroprotective role of RA in recovery from SCI is related to prevention of of BSCB disruption via the activation of autophagic flux and the inhibition of ER stress-induced cell apoptosis. These findings lay the groundwork for future translational studies of RA for CNS diseases, especially those related to BSCB disruption.

Bafilomycin A1 Attenuates Osteoclast Acidification and Formation, Accompanied by Increased Levels of SQSTM1/p62 Protein

Vacuolar proton pump H(+)-adenosine triphosphatases (V-ATPases) play an important role in osteoclast function. Further understanding of the cellular and molecular mechanisms of V-ATPase inhibition is vital for the development of anti-resorptive drugs specifically targeting osteoclast V-ATPases. In this study, we observed that bafilomycin A1, a naturally-occurring inhibitor of V-ATPases, increased the protein level of SQSTM1/p62, a known negative regulator of osteoclast formation. Consistently, we found that bafilomycin A1 diminishes the intracellular accumulation of the acidotropic probe lysotracker in osteoclast-like cells; indicative of reduced acidification. Further, bafilomycin A1 inhibits osteoclast formation with attenuation of cell fusion and multi-nucleation of osteoclast-like cells during osteoclast differentiation. Taken together, these data indicate that bafilomycin A1 attenuates osteoclast differentiation in part via increased levels of SQSTM1/p62 protein, providing further mechanistic insight into the effect of V-ATPase inhibition in osteoclasts.

The relationship between weight change and risk of hip fracture: meta-analysis of prospective studies

The relationship between weight change and risk of hip fracture is still controversial. We searched PubMed and Embase for studies on weight change and risk of hip fracture. Eight prospective studies were included. The weight loss studies included 85592 participants with 1374 hip fractures, and the weight gain studies included 80768 participants with 732 hip fractures. Weight loss is more likely a risk factor of hip fracture, with an adjusted RR (Relative Risk) (95% CI) of 1.84 (1.45, 2.33). In contrast, weight gain can decrease the risk of hip fracture, with an adjusted RR (95% CI) of 0.73 (0.61, 0.89). Dose-response meta-analysis shows that the risk of hip fracture is an ascending curve, with an increase of weight loss above the line of RR = 1; this trend is consistent with the results of forest plots that examine weight loss and hip fracture. For weight gain and risk of hip fracture, the descending curve below the line of RR = 1; this trend is consistent with the results of forest plots that examine weight gain and hip fracture. Our meta-analysis suggests that weight loss may be a risk factor for hip fracture and that weight gain may be a protective factor for hip fracture.

Gelatin Nanostructured Lipid Carriers Incorporating Nerve Growth Factor Inhibit Endoplasmic Reticulum Stress-Induced Apoptosis and Improve Recovery in Spinal Cord Injury

Clinical translation of growth factor therapies faces multiple challenges; the most significant one is the short half-life of the naked protein. Gelatin nanostructured lipid carriers (GNLs) had previously been used to encapsulate the basic fibroblast growth factor to enhance the functional recovery in hemiparkinsonian rats. In this research, we comparatively study the enhanced therapy between nerve growth factor (NGF) loaded GNLs (NGF-GNLs) and NGF only in spinal cord injury (SCI). The effects of NGF-GNLs and NGF only were tested by the Basso-Beattie-Bresnahan (BBB) locomotion scale, inclined plane test, and footprint analysis. Western blot analysis and immunofluorescent staining were further performed to identify the expression of ER stress-related proteins, neuron-specific marker neuronal nuclei (NeuN), and growth-associated protein 43 (GAP43). Correlated downstream signals Akt/GSK-3β and ERK1/2 were also analyzed with or without inhibitors. Results showed that NGF-GNLs, compared to NGF only, enhanced the neuroprotection effect in SCI rats. The ER stress-induced apoptosis response proteins CHOP, GRP78 and caspase-12 inhibited by NGF-GNL treatment were more obvious. Meanwhile, NGF-GNLs in the recovery of SCI are related to the inhibition of ER stress-induced cell death via the activation of downstream signals PI3K/Akt/GSK-3β and ERK1/2.

Long-term effects of the Chêneau brace on coronal and sagittal alignment in adolescent idiopathic scoliosis

OBJECT

The aim of the present study was to retrospectively evaluate progressive correction of coronal and sagittal alignment and pelvic parameters in patients treated with a Chêneau brace.

METHODS

Thirty-two patients with adolescent idiopathic scoliosis (AIS) were assessed before initiation of bracing treatment and at the final follow-up. Each patient underwent radiological examinations, and coronal, sagittal, and pelvic parameters were measured.

RESULTS

No statistically significant modification of the Cobb angle was noted. The pelvic incidence remained unchanged in 59% of the cases and increased in 28% of the cases. The sacral slope decreased in 34% of the cases but remained unchanged in 50%. Thoracic kyphosis and lumbar lordosis were significantly decreased, whereas the sagittal vertical axis was significantly increased from a mean of -44.0 to -30.2 mm (p = 0.02). The mean pelvic tilt increased significantly from 4.5° to 8.3° (p = 0.002).

CONCLUSIONS

The Chêneau brace can be useful for preventing curvature progression in patients with AIS. However, the results of this study reveal high variability in the effect of brace treatment on sagittal and pelvic alignment. Treatment with the Chêneau brace may also influence sagittal global balance.

Computed tomography morphometric analysis for C-1 posterior arch crossing screw placement in the pediatric cervical spine

OBJECT

The goal of this study was to evaluate the feasibility of the C-1 posterior arch crossing screw fixation technique in the pediatric age group.

METHODS

One hundred twenty-three pediatric patients were divided into 6 age groups. Computed tomography morphometric analysis of the C-1 posterior arch was performed. Measurements included height, width, and length. Statistical analysis was performed using the Student t-test and linear regression analysis.

RESULTS

The mean measurement of the posterior arch was height (6.35 ± 1.80 mm), width (Width 1: 4.48 ± 1.25 mm; Width 2: 4.42 ± 0.68 mm; Width 3: 4.42 ± 0.50 mm), and length (14.48 ± 1.67 mm). Seven (6.93%) of the 101 children in Groups 1-4 and 13 (59.1%) of the 22 children in Groups 5 and 6 could safely accommodate placement of C-1 posterior arch crossing screws.

CONCLUSIONS

This investigation found that a C-1 posterior arch crossing screw was feasible in this group of Chinese pediatric patients, particularly in those 13 years and older. Preoperative thin-cut CT is essential for identifying children in whom this technique is applicable and for planning screw placement.

A novel technique of two-hole guide tube for percutaneous anterior odontoid screw fixation

BACKGROUND CONTEXT

Surgical stabilization is recommended for odontoid fractures with mechanical instability. Compared with C1-C2 fusion, percutaneous anterior odontoid screw fixation has the advantages of preserving C1/C2 motion and being a minimally invasive procedure. However, determining the optimal screw trajectory is often difficult. When an initial suboptimal K-wire hole is drilled, it is especially difficult to drill a second optimal K-wire trajectory because the initial hole will be entered inadvertently.

PURPOSE

To design a novel device, two-hole guide tube, to make drilling a second optimal K-wire trajectory easier, and thus, avoid unnecessary additional surgical time and reduce the likelihood of needing to change the procedure to traditional open surgery.

STUDY DESIGN

A technical report.

METHODS

Fifty-three patients with odontoid fractures were treated by percutaneous anterior odontoid screw fixation in our hospital, and the initial K-wire trajectories of 16 cases (12 men and 4 women) among the 53 patients were imperfect. The two-hole guide tube was applied for drilling the second trajectory in each of these 16 cases.

RESULTS

No complications associated with this technique occurred. Satisfactory results and good screw placement was achieved in all patients. Radiographic fusion was confirmed for 15 of 16 patients. None of the patients experienced clinical symptoms or screw loosening or breakage in this study.

CONCLUSIONS

Our novel device, two-hole guide tube, can be used to reduce the difficulty associated with redrilling an optimal K-wire trajectory if the initial trajectory is imperfect during percutaneous anterior odontoid screw fixation. Moreover, by referring to the initial misplaced K-wire, a more accurate trajectory for the second K-wire can be achieved.

The accuracy of a method for printing three-dimensional spinal models

Background

To study the morphology of the human spine and new spinal fixation methods, scientists require cadaveric specimens, which are dependent on donation. However, in most countries, the number of people willing to donate their body is low. A 3D printed model could be an alternative method for morphology research, but the accuracy of the morphology of a 3D printed model has not been determined.

Methods

Forty-five computed tomography (CT) scans of cervical, thoracic and lumbar spines were obtained, and 44 parameters of the cervical spine, 120 parameters of the thoracic spine, and 50 parameters of the lumbar spine were measured. The CT scan data in DICOM format were imported into Mimics software v10.01 for 3D reconstruction, and the data were saved in .STL format and imported to Cura software. After a 3D digital model was formed, it was saved in Gcode format and exported to a 3D printer for printing. After the 3D printed models were obtained, the above-referenced parameters were measured again.

Results

Paired t-tests were used to determine the significance, set to P<0.05, of all parameter data from the radiographic images and 3D printed models. Furthermore, 88.6% of all parameters of the cervical spine, 90% of all parameters of the thoracic spine, and 94% of all parameters of the lumbar spine had Intraclass Correlation Coefficient (ICC) values >0.800. The other ICC values were <0.800 and >0.600; none were <0.600.

Conclusion

In this study, we provide a protocol for printing accurate 3D spinal models for surgeons and researchers. The resulting 3D printed model is inexpensive and easily obtained for spinal fixation research.

Autologous Olfactory Lamina Propria Transplantation for Chronic Spinal Cord Injury: Three-Year Follow-Up Outcomes From a Prospective Double-Blinded Clinical Trial

We did a clinical trial to determine whether olfactory mucosa lamina propria (OLP) transplants promote regeneration and functional recovery in chronic human spinal cord injury (SCI). The trial randomized 12 subjects to OLP transplants (n = 8) or control sham surgery (n = 4). The subjects received magnetic resonance imaging (MRI), electromyography (EMG), urodynamic study (UDS), American Spinal Injury Association impairment scale (AIS), and other functional assessments. OLP-transplanted subjects recovered more motor, sensory, and bladder function compared to sham-operated subjects. At 3 years after OLP transplant, one patient improved from AIS A to C and another recovered from AIS A to B, two recovered more than three segmental sensory levels, two had less spasticity, two had altered H-reflexes and SSEP, two regained bladder and anorectal sensation and had improved bladder compliance on UDS. OLP-treated patients had partial or complete tissue bridges at the injury site compared to cavitary gaps in sham-operated patients. The limited recovery suggests that OLP transplants alone do not have significant benefits but may provide a rationale for larger randomized trials or combination therapies.

[Treatment of low lumbar degenerative disease with unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation]

OBJECTIVE

To explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease.

METHODS

From January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI).

RESULTS

All patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P < 0.05).

CONCLUSION

Unilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.

Minimum 4-year outcomes of cervical total disc arthroplasty versus fusion: a meta-analysis based on prospective randomized controlled trials

The prevalence of cervical disc disease is high, and the traditional surgical method of anterior cervical discectomy and fusion (ACDF) carries with it the disadvantages of motion loss at the operated level, and accelerated adjacent level disc degeneration. Preliminary results of the efficacy and reoperative rate comparing TDA versus ACDF have been reported; however, the long-term outcomes of TDA versus ACDF still remain a topic of debate. This review was prepared following the standard procedures set forth by the Cochrane Collaboration organization, and preferred reporting items for systematic reviews and meta-analyses (PRISMA). The only studies included were randomized controlled trials with a minimum of 4 years of follow-up data. The meta-analysis included the neck disability index (NDI), visual analog scale (VAS) of neck and arm pain, SF-36 physical component scores (SF-36 PCS), over success, neurological success, work status, implant-related complications, and secondary surgery events. Four randomized controlled trials meet the inclusion criteria. The long-term improvement of NDI, VAS of neck and arm pain, SF-36 PCS, over success, and neurological success favored the TDA group. The TDA group also had a lower incidence of secondary surgery for both the index level (RR: 0.45 [0.28, 0.72]) and adjacent level (RR: 0.53 [0.33, 0.88]). In this meta-analysis of 4 included RCTs with a minimum 4 years of follow-ups, total disc arthroplasty showed improvements over ACDF as measured by the NDI, VAS of neck and arm pain, and SF-36 PCS.

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.

Analysis of differentially expressed lncRNAs in differentiation of bone marrow stem cells into neural cells

Many studies have reported micro RNAs involved in the differentiation of bone marrow mesenchymal stem cells (BMSCs) into neural cells; however, the roles of long non-coding RNAs (lncRNAs) in the differentiation of BMSCs into neural cells remain poorly understood. We used microarray assays to compare the lncRNA and messenger RNA (mRNA) expression profiles in BMSCs and neural-induced BMSCs. We found a total of 24 lncRNAs and 738 mRNAs that were upregulated and 32 lncRNAs and 682 mRNAs that were downregulated in samples induced for 3h; 27 lncRNAs and 864 mRNAs that were upregulated and 37 lncRNAs and 968 mRNAs that were downregulated in 6h samples; and 23 lncRNAs and 1159 mRNAs that were upregulated or downregulated in both the 3h and 6h samples. For 23 differentially lncRNAs and 83 differentially mRNAs, 256 matched lncRNA-mRNA pairs were found. GO (Gene ontology) analysis showed that these lncRNAs were associated with biological processes, cellular components, and molecular functions. Twenty-five pathways were identified by pathway analysis. Then, RT-qPCR validation of the differentially expressed H19, Esco2, Pcdhb18, and RGD1560277 genes confirmed the microarray data. Our study revealed the expression patterns of lncRNAs in the differentiation of BMSCs into neural cells, and many lncRNAs were differentially expressed in induced BMSCs, suggesting that they may play key roles in processes of differentiation. Our findings may promote the use of BMSCs to treat neurodegenerative diseases and trauma.

Chronic unilateral locked facet joint with spinal cord injury in a 26-month-old child: A case report

OBJECTIVES

This study presents the successful posterior surgical reduction and fusion on a 26-month-old child with chronic unilateral locked facet joint and spinal cord injury (SCI).

METHODS

A 26-month-old child with chronic unilateral locked facet joint and SCI treated by posterior surgical reduction and fusion. Plaster external fixation was applied and rehabilitation exercise was trained post-operatively.

RESULTS

Chronic unilateral locked facet joint was reduced successfully and bone fusion of C4/5 was achieved 3 months after surgery. The function of both lower limbs was improved 1 year after surgery, aided with physical rehabilitation.

CONCLUSION

Unilateral locked facet joint in pediatric population is rare. Few clinical experiences were found in the literature. Non-surgical treatment has advantages of not being invasive and is preferred for acute patients; however, it may not be suitable for chronic unilateral locked facet joint with SCI, in which surgical intervention is needed.

The radiological feature of anterior occiput-to-axis screw fixation as it guides the screw trajectory on 3D printed models: a feasibility study on 3D images and 3D printed models

Anterior occiput-to-axis screw fixation is more suitable than a posterior approach for some patients with a history of posterior surgery. The complex osseous anatomy between the occiput and the axis causes a high risk of injury to neurological and vascular structures, and it is important to have an accurate screw trajectory to guide anterior occiput-to-axis screw fixation. Thirty computed tomography (CT) scans of upper cervical spines were obtained for three-dimensional (3D) reconstruction. Cylinders (1.75 mm radius) were drawn to simulate the trajectory of an anterior occiput-to-axis screw. The imitation screw was adjusted to 4 different angles and measured, as were the values of the maximized anteroposterior width and the left-right width of the occiput (C0) to the C1 and C1 to C2 joints. Then, the 3D models were printed, and an angle guide device was used to introduce the screws into the 3D models referring to the angles calculated from the 3D images. We found the screw angle ranged from α1 (left: 4.99±4.59°; right: 4.28±5.45°) to α2 (left: 20.22±3.61°; right: 19.63±4.94°); on the lateral view, the screw angle ranged from β1 (left: 13.13±4.93°; right: 11.82±5.64°) to β2 (left: 34.86±6.00°; right: 35.01±5.77°). No statistically significant difference was found between the data of the left and right sides. On the 3D printed models, all of the anterior occiput-to-axis screws were successfully introduced, and none of them penetrated outside of the cortex; the mean α4 was 12.00±4.11 (left) and 12.25±4.05 (right), and the mean β4 was 23.44±4.21 (left) and 22.75±4.41 (right). No significant difference was found between α4 and β4 on the 3D printed models and α3 and β3 calculated from the 3D digital images of the left and right sides. Aided with the angle guide device, we could achieve an optimal screw trajectory for anterior occiput-to-axis screw fixation on 3D printed C0 to C2 models.

Percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion: a radiological and cadaveric study

PURPOSE

To design and investigate a novel technique of percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion.

METHODS

CT scans of 45 patients were collected and imported into Mimics software for three-dimensional (3D) reconstruction. Cylinders were drawn to simulate the trajectory of the oblique screw. Six measurements were obtained for each unit to design a right size cage: a the distance between the intersection of the simulated trajectory of the screw with the inferior border of the upper vertebra and its anteroinferior corner; b the distance between the intersection of the simulated trajectory of the screw with the superior border of the inferior vertebra and its anterosuperior corner; h the height of the intervertebral space; θ the angle between simulated trajectory of screw and the upper endplate of inferior vertebra; uw: the width of the inferior endplate of upper vertebra; iw: the width of upper endplate of inferior vertebra. Three intact adult fresh-frozen cadaveric specimens were obtained, percutaneous posterior transdiscal oblique screw fixation was performed under X-ray apparatus, and interbody cage was implanted by assistance with special self-retaining retractor system and endoscope.

RESULTS

According to the results of data measured from 3D images, trapezoid shape interbody cages with suitable size were designed. Percutaneous posterior oblique screw fixation with lateral interbody fusion was performed on three cadaveric specimens successfully.

CONCLUSION

Using specially designed trapezoid shape interbody cages, assisted by intra-operative image intensification and endoscope, it is feasible to perform percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion technique.

The relationship between vitamin A and risk of fracture: meta-analysis of prospective studies

Osteoporotic fracture is a significant cause of morbidity and mortality and is a challenging global health problem. Previous reports of the relation between vitamin A intake or blood retinol and risk of fracture were inconsistent. We searched Medline and Embase to assess the effects of vitamin A (or retinol or beta-carotene but not vitamin A metabolites) on risk of hip and total fracture. Only prospective studies were included. We pooled data with a random effects meta-analysis with adjusted relative risk (adj.RR) and 95% confidence interval (CI). We used Q statistic and I(2) statistic to assess heterogeneity and Egger's test to assess publication bias. Eight vitamin A (or retinol or beta-carotene) intake studies (283,930 participants) and four blood retinol level prospective studies (8725 participants) were included. High intake of vitamin A and retinol were shown to increase risk of hip fracture (adj.RR [95% CI] = 1.29 [1.07, 1.57] and 1.40 [1.03, 1.91], respectively), whereas beta-carotene intake was not found to increase the risk of hip fracture (adj.RR [95% CI] = 0.82 [0.59, 1.14]). Both high or low level of blood retinol was shown to increase the risk of hip fracture (adj.RR [95% CI] = 1.87 [1.31, 2.65] and 1.56 [1.09, 2.22], respectively). The risk of total fracture does not differ significantly by level of vitamin A (or retinol) intake or by blood retinol level. Dose-response meta-analysis shows a U-shaped relationship between serum retinol level and hip fracture risk. Our meta-analysis suggests that blood retinol level is a double-edged sword for risk of hip fracture. To avoid the risk of hip fracture caused by too low or too high a level of retinol concentration, we suggest that intake of beta-carotene (a provitamin A), which should be converted to retinol in blood, may be better than intake of retinol from meat, which is directly absorbed into blood after intake.

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.

Comparison of two anterior fusion methods in two-level cervical spondylosis myelopathy: a meta-analysis

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of anterior cervical corpectomy and fusion (ACCF) and anterior cervical discectomy and fusion (ACDF) for treating two-adjacent-level cervical spondylosis myelopathy (CSM).

DESIGN

A meta-analysis of the two anterior fusion methods was conducted. The electronic databases of PubMed, the Cochrane Central Register of Controlled Trials, ScienceDirect, CNKI, WANFANG DATA and CQVIP were searched. Quality assessment of the included studies was evaluated using the Cochrane Risk of Bias Tool and the Methodological Index for Non-Randomised Studies criteria. Pooled risk ratios of dichotomous outcomes and standardised mean differences (SMDs) of continuous outcomes were generated. Using the χ(2) and I(2) tests, the statistical heterogeneity was assessed. Subgroup and sensitivity analyses were also performed.

PARTICIPANTS

Nine eligible trials with a total of 631 patients and a male-to-female ratio of 1.38:1 were included in this meta-analysis.

INCLUSION CRITERIA

Randomised controlled trials (RCTs) and non-randomised controlled trials that adopted ACCF and ACDF to treat two-adjacent-level CSM were included.

RESULTS

No significant differences were identified between the two groups regarding hospital stay, the Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) scores for neck and arm pain, total cervical range of motion (ROM), fusion ROM, fusion rate, adjacent-level ossification and complications, while ACDF had significantly less bleeding (SMD=1.14, 95% CI (0.74 to 1.53)); a shorter operation time (SMD=1.13, 95% CI (0.82 to 1.45)); greater cervical lordosis, total cervical (SMD=-2.95, 95% CI (-4.79 to -1.12)) and fused segment (SMD=-2.24, 95% CI (-3.31 to -1.17)); higher segmental height (SMD=-0.68, 95% CI (-1.03 to -0.34)) and less graft subsidence (SMD=0.40, 95% CI (0.06 to 0.75)) compared to ACCF.

CONCLUSIONS

The results suggested that ACDF has more advantages compared to ACCF. However, additional high-quality RCTs and a longer follow-up duration are needed.

The effect of postural correction and subsequent balloon inflation in deformity correction of acute osteoporotic vertebral fractures

OBJECTIVE

To determine deformity correction by postural correction and subsequent balloon inflation in acute vertebral compression fractures (OVCFs) and to examine the effect of bone mineral density on deformity correction.

METHODS

A totol of 50 acute OVCFs received balloon kyphoplasty. Lateral radiographs were taken and analyzed at five different time points : 1) preoperative, 2) after placing the patient in prone hyperextended position, 3) after balloon inflation, 4) after deposition of the cement, and 5) postoperative. All fractures were analyzed for height restoration of anterior (Ha), middle (Hm) and posterior (Hp) vertebra as well as Cobb angle and Kyphotic angle. The bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry. According to the T-score, the patients were divided into two groups which were osteoporosis group and osteopenia group.

RESULTS

Postoperative measurements of Ha, Hm and the Cobb angle demonstrated significant reduction of 4.62 mm, 3.66 mm and 5.34° compared with the preoperative measurements, respectively (each p<0.05). Postural correction significantly increased Ha by 5.51 mm, Hm by 4.35 mm and improved the Cobb angle by 8.32° (each p<0.05). Balloon inflation did not demonstrate a significant improvement of Ha, Hm or the Cobb angle compared with baseline prone hyperextended. Postural correction led to greater improvements of Ha, Hm and Cobb angle in osteoporosis group than osteopenia group (each p<0.05).

CONCLUSION

In acute OVCFs, the height restoration was mainly attributed to postural correction rather than deformity correction by balloon inflation. BMD affected deformity correction in the process of postural correction.

Incidence of heterotopic ossification after implantation of interspinous process devices

OBJECT

This study aimed to investigate the incidence rate of heterotopic ossification (HO) after implantation of Coflex interspinous devices. Possible risk factors associated with HO were evaluated.

METHODS

The authors retrospectively analyzed patients who had undergone single-level (L4-5) implantation of a Coflex device for the treatment of lumbar spinal stenosis. Patient data recorded were age, sex, height, weight, body mass index, smoking habits, and surgical time. Heterotopic ossification was identified through lumbar anteroposterior and lateral view radiographs. The authors developed a simple classification for defining HO and compared HO-positive and HO-negative cases to identify possible risk factors.

RESULTS

Among 32 patients with follow-up times of 24-57 months, HO was detectable in 26 (81.2%). Among these 26 patients, HO was in the lateral space of the spinous process but not in the interspinous space in 8, HO was in the interspinous space but did not bridge the adjacent spinous process in 16, and interspinous fusion occurred at the level of the device in 2. Occurrence of HO was not associated with patient age, sex, height, weight, body mass index, smoking habits, or surgical time.

CONCLUSIONS

A high incidence of HO has been detected after implantation of Coflex devices. Clinicians should be aware of this possible outcome, and more studies should be conducted to clarify the clinical effects of HO.

Complications in degenerative lumbar disease treated with a dynamic interspinous spacer (Coflex)

PURPOSE

The purpose of this study was to quantify the intra- and postoperative complications of an interspinous process device (Coflex) in managing degenerative lumbar diseases and to investigate corresponding therapeutic strategies.

METHODS

Between January 2008 and December 2012, we retrospectively analysed a total of 131 patients who underwent decompressive surgery along with the Coflex system for the treatment of degenerative lumbar diseases. The related complications were reported, and appropriate measures were taken. Clinical outcomes and radiological data were collected and analysed, and clinical outcomes were evaluated with paired-samples T test.

RESULTS

Related complications occurred in 11 patients. Among them, six cases were found with surgical technique-related complications, including device-related complications in three cases: spinal process fracture (n = 1), Coflex loosening (n = 1), fixed-wing breakage (n = 1), dura mater tear in two cases and superficial wound infection in one case. All of them received corresponding conservative treatment and obtained a good result. The other five cases had non-device-related complications and required additional spinal surgery. The conservative therapy group had apparent improvement of VAS score and ODI, and remained well to final follow-up (P < 0.05). The second operation group also improved postoperatively (each P < 0.05).

CONCLUSION

The Coflex dynamic interspinous process device shows a low complication and re-operation rate. Standard operation and strict follow-up observation can effectively avoid surgical technique-related complications. The key points to ensure surgical effect and to reduce non-device-related complications are mastering surgical indications and thorough intra-operative decompression.

Regulation of autophagy and ubiquitinated protein accumulation by bFGF promotes functional recovery and neural protection in a rat model of spinal cord injury

The role of autophagy in the recovery of spinal cord injury remains controversial; in particular, the mechanism of autophagy regulated degradation of ubiquitinated proteins has not been discussed to date. In this study, we investigated the protective role of basic fibroblast growth factor (bFGF) both in vivo and in vitro and demonstrated that excessive autophagy and ubiquitinated protein accumulation is involved in the rat model of trauma. bFGF administration improved recovery and increased the survival of neurons in spinal cord lesions in the rat model. The protective effect of bFGF is related to the inhibition of autophagic protein LC3II levels; bFGF treatment also enhances clearance of ubiquitinated proteins by p62, which also increases the survival of neuronal PC-12 cells. The activation of the downstream signals of the PI3K/Akt/mTOR pathway by bFGF treatment was detected both in vivo and in vitro. Combination therapy including the autophagy activator rapamycin partially abolished the protective effect of bFGF. The present study illustrates that the role of bFGF in SCI recovery is related to the inhibition of excessive autophagy and enhancement of ubiquitinated protein clearance via the activation of PI3K/Akt/mTOR signaling. Overall, our study suggests a new trend for bFGF drug development for central nervous system injuries and sheds light on protein signaling involved in bFGF action.

The anatomic study of clival screw fixation for the craniovertebral region

PURPOSE

To study the anatomic parameters related to clival screw and establish reference data concerning the craniovertebral fixation technique.

METHODS

Morphometric measurement of the clivus and the surrounding anatomic structures were obtained on 41 dry bone specimens. Then, 2-D CT reconstruction of the craniovertebral region of 30 patients (19 men and 11 women, ranging in age from 20-64 years with an average age of 38.8 years) were performed to measure the safety range for a 3.5-mm screw placement. Nine entry points were evaluated. Finally, one male fresh cadaver specimen (age 46 years) was dissected to observe the craniovertebral region.

RESULTS

The clivus faces the basilar artery, the V ~ XII cranial nerves, the pons, and ventral medulla oblongata at its intracranial surface. The longitudinal diameter of extracranial clivus was 25.87 ± 2.64 mm. The narrowest diameter of the clivus was 12.84 ± 1.08 mm, the distance between the left and right hypoglossal canal was 32.70 ± 2.09 mm at its widest part. The distance between the left and right structures, the maximum value was 49.31 ± 4.16 mm at carotid canal, the minimum value was 16.54 ± 2.04 mm at the occipital condyle. The measurement of clival screws placement simulation via 2-D CT reconstruction images shows the maximum upper insertion angle of three components the optimal entry points, the candidate points, the limit entry points was 130.19°, 125.23° and 85.72°, and the total mean screw length was 7.57, 10.13 and 15.6 mm at the vertical entry angle, respectively.

CONCLUSIONS

Clival screw placement is a viable option for craniovertebral fixation. There is a safe scope for the screw length and angle of the screw placement. And, these parameters obtained in the present study will be helpful for anyone contemplating the use of clival screw fixation.

Management of acute combination atlas-axis fractures with percutaneous triple anterior screw fixation in elderly patients

INTRODUCTION

Patients with combined C1-2 fractures were often treated by posterior arthrodesis. However, elderly patients with multiple injuries (such as brain injury), the large surgical trauma of posterior arthrodesis will increase the risk of perioperative mortality. A minimally invasive technique may be better for them, and decrease the risk of perioperative mortality.

MATERIALS AND METHODS

Seven patients with combined C1-2 fractures underwent percutaneous anterior odontoid screw and anterior C1-2 transarticular screws (percutaneous triple anterior screws fixation). The surgical technique of percutaneous triple anterior screws fixation is described.

RESULTS

The operation performed on all patients successfully without technical difficulties, and no intra-operative surgery-related complications such as vertebral artery, nerve injury and soft tissue complications occurred. No pullout, loosening, or breakage of internal screws was observed. C1/2 stable was found in all cases and radiographic union achieved in all odontoid fractures.

CONCLUSION

Using the appropriate instruments allied to intra-operative image-intensification, we suggest that percutaneous triple anterior screw fixation is reliable, effective and minimally invasive procedure for elderly and brain injured patients suffering of combined atlas-axis fractures.

LEVEL OF EVIDENCE

Level IV. Retrospective study.