Is routine blood typing and screening necessary for degenerative cervical spine surgery patients in specialty surgical hospitals?

BACKGROUND: Blood loss warranting transfusion is a relatively rare requirement for degenerative cervical spine surgery. Despite this rarity, pretransfusion testing (blood typing, screening, and cross-matching) has become routine in most parts of the world. We sought to determine if such routine testing is necessary for patients who undergo degenerative cervical spine surgery patients in specialty surgical hospitals by (1) measuring the current rate of intraoperative transfusions in degenerative cervical spine surgery and (2) identifying risk factors for transfusions. STUDY METHODS: Retrospective review was performed on patients who underwent degenerative cervical spine surgery in two institutions. Demographic and baseline clinical and laboratory data were collected and analyzed to identify predictors of transfusion. Bivariate and multivariate logistic regression analysis was performed to identify perioperative transfusion risk factors. RESULTS: Overall transfusion rate was 1.9% (7/372), with no emergent transfusions. Decreases between preoperative and postoperative hemoglobin and hematocrit were 1.4 (SD 1.1) g/dL and 7.2 (SD 4.1) %, respectively. Multivariate logistic regression identified preoperative Hgb lower than 12 gr/dl (OR 27.62; 95% CI 4.31-176.96; p < 0.001) as significant independent transfusion risk factor. The receiver operating characteristic (ROC) curve for the model showed a very good discriminatory power with an area under the curve of 0.91. DISCUSSION: Our study suggests that pretransfusion testing for all patients undergoing degenerative cervical spine surgery is unnecessary. We recommend that only patients with preoperative Hgb lower than 12 gr/dl would routinely need pretransfusion testing.

Can IGF-1 serve as a reliable skeletal maturity indicator? A meta-analysis.

BACKGROUND: Many clinical studies have evaluated the role of biochemical mediators like insulin-like growth factor 1 (IGF-1) in assessment of skeletal maturity. But still the reliability of IGF­1 as an indicator of skeletal maturity remains controversial. OBJECTIVE: To assess the correlation between IGF­1 and different radiographic skeletal maturity indicators. SEARCH METHODS: Seven electronic databases (PubMed, Scopus, EMBASE, Medline, Cochrane CENTRAL, Web of Science and SciELO) were searched until January 2020 without any restriction based on language or date of publication. SELECTION CRITERIA: The study design included cross-sectional and longitudinal studies comparing IGF­1 and other skeletal maturity indicators (SMIs). DATA COLLECTION AND ANALYSIS: Data extraction was done by two reviewers independently; 15 studies were eligible to be included in the quantitative synthesis. RESULTS: There was significant positive correlation between IGF­1 and different SMIs until puberty which was 0.95 (confidence interval [CI] = 0.89, 1.02) for males and 0.87 (CI = 0.77, 0.97) for females. A negative correlation between IGF­1 and different SMIs was found after puberty which was -0.86 (CI = -0.97, -0.75) for males and -0.89 (CI = -0.98, -0.81) for females. The type of SMI compared and type of IGF­1 sample used accounted for the high heterogeneity found across the studies. Chronological age and number of months passed after puberty showed moderate negative correlation with mean IGF­1 levels which were -0.57 (CI = -0.67, -0.47) and -0.54 (CI = -0.66, -0.42). Annual increments in mandibular length showed significant positive correlation of 0.69 (CI = 0.48, 0.90). CONCLUSIONS: IGF­1 would serve as a promising alternative to conventional radiographic skeletal maturity indicators and in predicting the amount of residual mandibular growth.

Fluoroscopy-Guided Blockade of the Greater Occipital Nerve in Cadavers: A Comparison of Spread and Nerve Involvement for Different Injectate Volumes.

Background: Fluoroscopy-guided blockade of the greater occipital nerve (GON) is an accepted method for treating the symptoms of cervicogenic headaches (CGHs). However, the spread patterns among different injectate volumes of fluoroscopy-guided GON blocks are not well defined. Objective: A cadaveric study was established to determine the spread patterns of different volumes of dye injectate within a fluoroscopic GON block. Study Design. Cadaveric study. Setting. Xingtai Institute of Orthopaedics; Orthopaedic Hospital of Xingtai. Methods: 15 formalin-fixed cadavers with intact cervical spines were randomized in a 1 : 1 : 1 ratio to receive a fluoroscopy-guided GON injection of a 2, 3.5, or 5 ml volume of methylene blue. The suboccipital regions were dissected to investigate nerve involvement. Results: The suboccipital triangle regions, including the suboccipital nerves and GONs, were deeply stained in all cadavers. The third occipital nerve (TON) was stained in 7 of 10 administered 2 ml injections and in all the 3.5 ml and 5 ml injections. Compared to the 3 ml injectate group, the 5 mL cohort consistently saw injectate spreading to both superficial and distant muscles. Limitations. Given that cadavers were used in this study, cadaveric soft tissue composition and architecture can potentially become distorted and consequently affect injectate diffusion. Conclusions: A 3.5 or 5 mL fluoroscopy-guided GON injection of methylene blue successfully stains the GON, TON, and suboccipital nerves. This suggests that such an injection would generate blockade of all three nerve groups, which may contribute to the efficacy of the block for CGH. A volume of 3.5 ml may be enough for the performance of a fluoroscopy-guided GON block for therapeutic purposes.

Ingrowth of Nociceptive Receptors into Diseased Cervical Intervertebral Disc Is Associated with Discogenic Neck Pain.

OBJECTIVE: To investigate the distribution of nociceptive nerve fibers in the cervical intervertebral discs of patients with chronic neck pain and determine whether these nociceptive nerve fibers are related to discogenic neck pain. METHODS: We collected 43 samples of cervical intervertebral discs from 34 patients with severe chronic neck pain (visual analog scale [VAS] ≥ 70 mm), 42 samples from 36 patients who suffered cervical spondylotic radiculopathy or myelopathy without neck pain or with mild neck pain (VAS ≤ 30 mm) and 32 samples from eight donators to investigate their innervation immunohistochemically using an antibody against neuropeptide substance P. RESULTS: The immunohistochemical investigation revealed that substance P-positive nerve fibers were obviously increased in number and deeply ingrown into the inner anulus fibrosus and even into the nucleus pulposus in the degenerative cervical discs of patients with severe neck pain in comparison with the discs of patients with cervical spondylotic radiculopathy or myelopathy and normal control discs (P<0.01). CONCLUSIONS: The current study may indicate a key role of nociceptive nerve fibers in the pathogenesis of neck pain of cervical disc origin.

Vancomycin concentrations in the cervical spine after intravenous administration: results from an experimental pig study.

Background and purpose - Vancomycin may be an important drug for intravenous perioperative antimicrobial prophylaxis in spine surgery. We assessed single-dose vancomycin intervertebral disc, vertebral cancellous bone, and subcutaneous adipose tissue concentrations using microdialysis in a pig model. Material and methods - 8 female pigs received 1,000 mg of vancomycin intravenously as a single dose over 100 minutes. Microdialysis probes were placed in the C3-C4 intervertebral disc, C3 vertebral cancellous bone, and subcutaneous adipose tissue, and vancomycin concentrations were obtained over 8 hours. Venous blood samples were obtained as reference. Results - Ranging from 0.24 to 0.60, vancomycin tissue penetration, expressed as the ratio of tissue to plasma area under the concentration-time curve from 0 to the last measured value, was incomplete for all compartments. The lowest penetration was found in the intervertebral disc. The time to a mean clinically relevant minimal inhibitory concentration (MIC) of 4 µg/mL was 3, 17, 25, and 156 min for plasma, subcutaneous adipose tissue, vertebral cancellous bone, and the intervertebral disc, respectively. In contrast to the other compartments, a mean MIC of 8 µg/mL was not reached in the intervertebral disc. An approximately 3-times longer elimination rate was observed in the intervertebral disc in comparison with all the other compartments (p < 0.001), and the time to peak drug concentration was higher for all tissues compared with plasma Interpretation - Preoperative administration of 1,000 mg of vancomycin may provide adequate vancomycin tissue concentrations with a considerable delay, though tissue penetration was incomplete. However, in order also to achieve adequate intervertebral disc concentrations in all individuals and accommodating a potentially higher MIC target, supplemental application of vancomycin may be necessary.

Biochemical and biomechanical characterisation of equine cervical facet joint cartilage.

BACKGROUND: The equine cervical facet joint is a site of significant pathology. Located bilaterally on the dorsal spine, these diarthrodial joints work in conjunction with the intervertebral disc to facilitate appropriate spinal motion. Despite the high prevalence of pathology in this joint, the facet joint is understudied and thus lacking in viable treatment options. OBJECTIVE: The goal of this study was to characterise equine facet joint cartilage and provide a comprehensive database describing the morphological, histological, biochemical and biomechanical properties of this tissue. STUDY DESIGN: Descriptive cadaver studies. METHODS: A total of 132 facet joint surfaces were harvested from the cervical spines of six skeletally mature horses (11 surfaces per animal) for compiling biomechanical and biochemical properties of hyaline cartilage of the equine cervical facet joints. Gross morphometric measurements and histological staining were performed on facet joint cartilage. Creep indentation and uniaxial strain-to-failure testing were used to determine the biomechanical compressive and tensile properties. Biochemical assays included quantification of total collagen, sulfated glycosaminoglycan and DNA content. RESULTS: The facet joint surfaces were ovoid in shape with a flat articular surface. Histological analyses highlighted structures akin to articular cartilage of other synovial joints. In general, biomechanical and biochemical properties did not differ significantly between the inferior and superior joint surfaces as well as among spinal levels. Interestingly, compressive and tensile properties of cervical facet articular cartilage were lower than those of articular cartilage from other previously characterised equine joints. Removal of the superficial zone reduced the tissue's tensile strength, suggesting that this zone is important for the tensile integrity of the tissue. MAIN LIMITATIONS: Facet surfaces were sampled at a single, central location and do not capture the potential topographic variation in cartilage properties. CONCLUSIONS: This is the first study to report the properties of equine cervical facet joint cartilage and may serve as the foundation for the development of future tissue-engineered replacements as well as other treatment strategies.

Kinetic DTI of the cervical spine: diffusivity changes in healthy subjects.

INTRODUCTION: The study aims to assess the influence of neck extension on water diffusivity within the cervical spinal cord. METHODS: IRB approved the study in 22 healthy volunteers. All subjects underwent anatomical MR and diffusion tensor imaging (DTI) at 1.5 T. The cervical cord was imaged in neutral (standard) position and extension. Segmental vertebral rotations were analyzed on sagittal T2-weighted images using the SpineView® software. Spinal cord diffusivity was measured in cross-sectional regions of interests at multiple levels (C1-C5). RESULTS: As a result of non-adapted coil geometry for spinal extension, 10 subjects had to be excluded. Image quality of the remaining 12 subjects was good without any deteriorating artifacts. Quantitative measurements of vertebral rotation angles and diffusion parameters showed good intra-rater reliability (ICC = 0.84-0.99). DTI during neck extension revealed significantly decreased fractional anisotropy (FA) and increased radial diffusivity (RD) at the C3 level and increased apparent diffusion coefficients (ADC) at the C3 and C4 levels (p < 0.01 Bonferroni corrected). The C3/C4 level corresponded to the maximal absolute change in segmental vertebral rotation between the two positions. The increase in RD correlated positively with the degree of global extension, i.e., the summed vertebral rotation angle between C1 and C5 (R = 0.77, p = 0.006). CONCLUSION: Our preliminary results suggest that DTI can quantify changes in water diffusivity during cervical spine extension. The maximal differences in segmental vertebral rotation corresponded to the levels with significant changes in diffusivity (C3/C4). Consequently, kinetic DTI measurements may open new perspectives in the assessment of neural tissue under biomechanical constraints.

Pharmacokinetics of single-dose cefuroxime in porcine intervertebral disc and vertebral cancellous bone determined by microdialysis.

BACKGROUND: Pyogenic spondylodiscitis is associated with prolonged antimicrobial therapy and high relapse rates. Nevertheless, tissue pharmacokinetic studies of relevant antimicrobials in both prophylactic and therapeutic situations are still sparse. Previous approaches based on bone biopsy and discectomy exhibit important methodological limitations. PURPOSE: The objective of this study was to assess the C3-C4 intervertebral disc (IVD), C3 vertebral body cancellous bone, and subcutaneous adipose tissue (SCT) pharmacokinetics of cefuroxime by use of microdialysis in a large animal model. STUDY DESIGN: This was a single-dose, dense sampling large animal study of cefuroxime spine penetration. METHODS: Ten female pigs were assigned to receive 1,500 mg of cefuroxime intravenously over 15 minutes. Measurements of cefuroxime were obtained from plasma, SCT, vertebral cancellous bone, and IVD for 8 hours thereafter. Microdialysis was applied for sampling in solid tissues. RESULTS: For both IVD and vertebral cancellous bone, the area under the concentration curve from zero to the last measured value (AUC(0-last)) was significantly lower than that of free plasma. As estimated by the ratio of tissue AUC(0-last) to plasma AUC(0-last), tissue penetration (95% confidence interval) of cefuroxime was significantly incomplete for the IVD 0.78 (0.57; 0.99), whereas for vertebral cancellous bone 0.78 (0.51; 1.04) and SCT 0.94 (0.73; 1.15) it was not. The penetration of cefuroxime from plasma to the IVD was delayed, and the maximal concentration and the elimination of cefuroxime were also reduced compared with both SCT and vertebral cancellous bone. Because of this delay in elimination of cefuroxime, the time with concentrations above the minimal inhibitory concentration (T(>MIC)) was significantly longer in the IVD compared with the remaining compartments up to MICs of 6 µg/mL. CONCLUSIONS: Microdialysis was successfully applied for serial assessment of the concentration of cefuroxime in the IVD and the vertebral cancellous bone. Penetration of cefuroxime from plasma to IVD was found to be incomplete and delayed, but because of a prolonged elimination, superior T(>MIC) was found in the IVD up to MICs of 6 µg/mL.

Structural and Ultrastructural Analysis of the Cervical Discs of Young and Elderly Humans.

Several studies describing the ultrastructure and extracellular matrix (ECM) of intervertebral discs (IVDs) involve animal models and specimens obtained from symptomatic individuals during surgery for degenerative disease or scoliosis, which may not necessarily correlate to changes secondary to normal aging in humans. These changes may also be segment-specific based on different load patterns throughout life. Our objective was to describe the ECM and collagen profile of cervical IVDs in young (G1 - <35 years) and elderly (G2 - >65 years) presumably-asymptomatic individuals. Thirty cervical discs per group were obtained during autopsies of presumably-asymptomatic individuals. IVDs were analyzed with MRI, a morphological grading scale, light microscopy, scanning electron microscopy (SEM) and immunohistochemistry (IHC) for collagen types I, II, III, IV, V, VI, IX and X. Macroscopic degenerative features such as loss of annulus-nucleus distinction and fissures were found in both groups and significantly more severe in G2 as expected. MRI could not detect all morphological changes when compared even with simple morphological inspection. The loose fibrocartilaginous G1 matrix was replaced by a denser ECM in G2 with predominantly cartilaginous characteristics, chondrocyte clusters and absent elastic fibers. SEM demonstrated persistence of an identifiable nucleus and Sharpey-type insertion of cervical annulus fibers even in highly-degenerated G2 specimens. All collagen types were detected in every disc sector except for collagen X, with the largest area stained by collagens II and IV. Collagen detection was significantly decreased in G2: although significant intradiscal differences were rare, changes may occur faster or earlier in the posterior annulus. These results demonstrate an extensive modification of the ECM with maintenance of basic ultrastructural features despite severe macroscopic degeneration. Collagen analysis supports there is not a "pathologic" collagen type and changes are generally similar throughout the disc. Understanding the collagen and ultrastructural substrate of degenerative changes in the human disc is an essential step in planning restorative therapies.

Comparison of trace element concentration in bone and intervertebral disc tissue by atomic absorption spectrometry techniques.

BACKGROUND: Trace element (TE) analysis in human tissue has the dual purpose of assessing environmental pollution and metabolism. In literature, bone TE analysis is common, but studies in intervertebral disc (IVD) tissue are lacking. The aim of the study was evaluation of the difference of TE concentration in intervertebral disc and bone in patients with degenerative changes. The comparison of the tissues differing in metabolism, blood perfusion, or separateness from adjoining tissues but playing similar biomechanical role and presenting some common morphological traits may shed new light on metabolism nuances, degenerative process, as well as accumulation potential of IVD in respect to bone. METHODS: In the study, we analyzed two types of samples: intervertebral disc (n =30, from 22 patients operated due to degenerative disc disease) and femoral bone (n =26, separately femoral head and neck, from 26 patients, acquired in total hip arthroplasty procedure in course of idiopathic osteoarthritis of the hip joint). In the samples we analyzed, with atomic absorption spectrometry, the concentrations of Pb, Ni, Mo, Cu, Mg, and Zn. RESULTS: The element concentrations identified in bone are comparable to those presented in the literature. In the case of Pb, Ni, Mo, Mg, and Zn, the concentration in the bone was 2 to 25.8 times higher than that observed in the disc. Only the Cu concentration was higher in disc tissue than in bone. In disc tissue, fewer samples had TE concentrations below the detection threshold. We found significant differences in TE profiles in the compared tissues. CONCLUSIONS: The results show that the disc could serve as a more stable compartment for evaluating TE concentration, especially for TEs that are environmentally related.

Melanotic schwannoma of the cervical spine progressing with pulmonary metastasis: case report.

Melanotic schwannoma (MS) is an unusual variant of nerve sheath neoplasm. Only 10% of these tumors will undergo malignant degeneration, with exceedingly rare reported metastasis. We present a 32-year-old woman with a 6-month history of cervical pain and left arm progressive weakness. Neurological examination showed a left upper limb radicular pain, with pyramidal syndrome at C5 level. The magnetic resonance imaging (MRI) study highlighted an intradural extramedullary heterogeneous mass along the spinal cord at the C4-C5 level, slightly hyperintense with T1 and hypointense with T2-weighted sequences, invading the left neural foramen. The patient underwent C3-C5 laminectomy with total resection of a black tumor. In the postoperative period, a patent deficit of shoulder abduction ensued related to the nervous section. Microscopically, compactly fascicles of spindle-shaped cells with pleomorphic and hypercromatic nuclei, dark brown intracellular pigments, as well as some mitotic figures were seen. Immunohistochemical stains for S-100, Human Melanoma Black-45 (HMB-45), and vimentin were positive, with Ki-67 Labelling Index (LI) of 15% compatible with MS. Six months after radiotherapy she presents local recurrence and lung metastatic dissemination of the MS. She underwent left pulmonary segmentectomy, followed by chemotherapy and radiosurgery. The patient developed a febrile neutropenia and worsening of general status, and died after 3 months due to respiratory complications. MS are rare tumors with potential for local recurrence and distal metastasis. Complete surgical resection remains as the treatment of choice, once the uncommon cases with malignant progression shows low response to chemo and radiotherapy.

Immunohistochemical profile of NF-κB/p50, NF-κB/p65, MMP-9, MMP-2, and u-PA in experimental cervical spondylotic myelopathy.

STUDY DESIGN: The immunohistochemical profile of nuclear factor-κ B (NF-κB)/p50, NF-κB/p65, matrix metalloproteinase (MMP)-9, MMP-2, and urokinase-type plasminogen activator (u-PA) proteins was examined in spinal cord tissues coming from rabbits, which underwent chronic cervical spinal cord compression. OBJECTIVE: To study the potential role of NF-κB and extracellular matrix proteins under the chronic mechanical compression of the cervical spinal cord. SUMMARY OF BACKGROUND DATA: Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction among adults older than 55 years. Neuronal loss, myelin destruction, axonal degeneration, and glial scar formation are the principal neuropathological features of CSM. However, the biologic pathways that lead to these features remain unclear. METHODS: In this study, we used a new animal experimental model of CSM developed in our laboratory. Briefly, after posterior cervical laminectomy, gradual and progressive compression (during 20 weeks) was achieved by introducing a piece of aromatic polyether (0.07 mm thick) under the C6 lamina in 15 New Zealand rabbits. In control animals (n = 15), the aromatic polyether was implanted and then removed after 60 seconds (sham operation). The immunoreactivity of p50 and p65 subunits of NF-kB, as well as that of MMP-2, MMP-9, and u-PA, was evaluated in paraffin-embedded spinal cord sections coming from both groups. The evaluation was performed using immunohistochemistry technique and the results were analyzed using SPSS for Windows, release 12.0 (SPSS Inc., Chicago, IL). RESULTS: Increased immunoreactivity of both NF-κB subunits, p50 and p65, as well as MMP-2, MMP-9, and u-PA was demonstrated in animals with CSM in comparison with controls. Statistical analysis of the results revealed strong positive correlation between NF-κB subunits immunoreactivity and that of MMP-9, MMP-2, and u-PA. CONCLUSION: There is a strong correlation between the immunoexpression of NF-κB/p50, NF-κB/p65, MMP-2, MMP-9, u-PA, and CSM.

[Biomechanical application of finite element method in upper cervical spine].

Biomechanics plays an important role in the pathogenesis of upper cervical spine disease. Traditional biomechanical test, such as animal experiment, physical experiment and vitro experiment exists many problems. Finite element method, a new biomechanical method, can repeat in sustainability study, change quality and quantity, provide the manifestation of local and internal region and make up the deficiency of current methods. The paper summaries the biomechanical application of finite element method in upper cervical spine, including the finite element modeling, pathophysiological mechanism of upper cervical spine and biomechanical analysis of internal fixation devices.

Mechanical testing of an absorbable hybrid fusion cage for the cervical spine.

Conventional fusion devices ("cages") are often used to join two vertebrae of the human spine and generally remain in the body for a lifetime and can theoretically lead to any complications. Therefore, an absorbable hybrid fusion cage consisting of a magnesium skeleton infiltrated with an absorbable polymer [poly-ε-caprolactone (PCL)] has been developed. The primary objective of the cage is to ensure an adequate stiffness of the disc space directly after the operation and to encourage the ingrowth of the new bone tissue to secure long life stability. Once a sufficiently rigid bone connection is formed, the implant should be absorbed. The purpose of this first study on the new absorbable fusion cage was to investigate the mechanical properties in vitro. Tensile tests were performed with tensile specimens type 1BA according to DIN EN ISO 527 made of PCL foamed using controlled expansion of saturated polymers (CESP). Furthermore, cyclic compression tests and compression tests with steady movement were performed with different designs of the new cage. Compression tests were also performed with vertebral endplates of ovine cadaveric spines. Foaming of PCL resulted in a modulus of elasticity of 135 MPa, which is approximately one third of unfoamed PCL. The results indicate that the initial compression strength of the implants should be adequate for the implantation in the cervical spine.

Is the fibronectin-aggrecan complex present in cervical disk disease?

OBJECTIVE: To investigate the presence of inflammatory cytokines and the fibronectin-aggrecan complex (FAC) in persons undergoing surgical treatment for cervical radiculopathy caused by disk herniation. DESIGN: Single-center, prospective, consecutive case series. SETTING: A single large academic institution. PATIENTS: A total of 11 patients with radiculopathic pain and magnetic resonance imaging findings positive for disk herniation elected to undergo single-level cervical diskectomy. METHODS OR INTERVENTIONS: Lavage was performed by needle injection and aspiration upon entering the disk space for fluoroscopic localization before diskectomy. MAIN OUTCOME MEASUREMENTS: The lavage fluid was assayed for pH and the FAC, as well as for the cytokines interleukin-6 (IL-6), interferon-γ, monocyte chemotactic protein (MCP), and macrophage inhibitory protein-1ß. RESULTS: The subjects were 7 women and 4 men with a mean age of 50.6 years (SE 9.7; range, 36-70 years). The mean concentrations (SE; range) in picograms per milliliter were 7.9 (4.4; 0-44) for IL-6, 25.3 (15.5; 0-159) for interferon-γ, 16.1 (11.9; 0-121) for MCP, and 6.1 (2.8; 0-29) for macrophage inhibitory protein-1ß. The optical density of the FAC at 450 nm was 0.151 (0.036; 0.1-0.32), and the pH was 6.68 (0.1; 6.10-7.15). Statistically significant correlations were found between MCP and FAC (P = .036) and between FAC and pH (P = .008). CONCLUSIONS: Biochemical analysis of injured cervical intervertebral disks reveals the presence of inflammatory markers such as MCP, fragments of structural matrix proteins such as FAC, and a correlation with pH. Further evaluation of the FAC as a potential diagnostic biomarker or therapeutic target is warranted in the cervical spine.

Zinc deficiency reduces bone mineral density in the spine of young adult rats: a pilot study.

The objective of this study was to investigate the effects of zinc deficiency initiated during adolescence on skeletal densitometry, serum markers of bone metabolism, femur minerals and morphometry in young adult rats. Ten-week-old male rats were fed a <1-mg Zn/kg diet (9ZD), a 5-mg Zn/kg diet (9MZD) or a 30-mg Zn/kg diet (9CTL) for up to 9 weeks. Analyses included bone mineral density, serum osteocalcin and C-terminal peptides of type I collagen, serum zinc, femur zinc, calcium and phosphorus, and femur morphometry. Bone mineral density was 14% lower in the spine of 9ZD, but was not altered in the whole body, tibia or femur, or in any of the aforementioned sites in 9MZD, compared to 9CTL. When adjusted for size, spine bone mineral apparent density was still 8% lower in 9ZD than 9CTL. Serum osteocalcin, a marker for bone formation, was approximately 33% lower in 9ZD compared to both 9MZD and 9CTL. The 9ZD and 9MZD had 57% lower femur zinc and 56-88% lower serum zinc concentrations compared to 9CTL. These findings indicate that severe zinc deficiency initiated during adolescence may have important implications for future bone health, especially with regards to bone consolidation in the spine.

[An imaging study on location of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine].

OBJECTIVE: To explore the location of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine,and to provide a quantitative data to evaluate the correct length of transarticual screws in lower cervical spine during procedure. METHODS: One hundred standard lateral X-ray films and fifty CT films on cervical spine were used to measure the distance of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine. HS, HM and HI were defined as parameters, which means the distance between the anterior border of the superior (HS), median (HM) and inferior (HI) part of facets and the posterior border of corresponding vertebral bodies. The value will be negative if the anterior border of the facet located before the vertebral body. RESULTS: 'HS > HM > HI' was found in all facets in lower cervical spine. The anterior border of the facet in C(3,4) located before the posterior border of the vertebral body of C3. The anterior border of C(4,5) and C(5,6) was inclined to posterior. The anterior border of C(6,7) located after the posterior border of the vertebral body of C6. The pattern of HS increased from C(3,4) to C(6,7), the minimal (0 +/- 0.25) mm and the maximal (2.91 +/- 1.05) mm. The tendency of HM raised from C(3,4) to C(6,7), the minimal (-1.57 +/- 0.53) mm and the maximal (1.54 +/- 0.39) mm. The pattern HI added from C(3,4) to C(6,7), the minimal (-2.03 +/- 0.40) mm and the maximal (1.08 +/- 0.70) mm. CONCLUSION: During the implantation of the transarticular screws, the tip of the screws should be 0-2 mm before the posterior border of the vertebral body of C3 at C(3,4), 0-2 mm after that of C4 at C(4,5), 0.5-2.5 mm at C(5,6) and 1-3 mm at C(6,7). The quantitative location between the anterior border of facets and the posterior border of the corresponding vertebral bodies can offer an indirect method to evaluate the correct length of transarticual screws in lower cervical spine during procedure.

Relationship of mandibular and cervical vertebral bone density using computed tomography.

OBJECTIVES: The purpose of this study is to compare mandibular and cervical vertebral bone density (BD) using CT. METHODS: Cervical CT images from 114 patients (46 women, 68 men; mean age 49 years) with various clinical symptoms (e.g. headache, vertigo and imbalance) were included in this study. The mandibular and cervical vertebral BD measurements, expressed in Hounsfield units, were performed by the same investigator on these sections. RESULTS: The relationship between cervical vertebral and mandibular BD was revealed by regression and with correlation analysis. The correlation coefficient was r = 0.269, r(2) = 0.07, P = 0.004, which is statistically significant because of the high number of patients. However, the r(2) was very small, indicating that the power of the relationship is low. The distribution diagrams of the cervical vertebrae and mandible BD between female and male patients were similar. The relationship between age and mandibular BD was very weak (r = 0.033, r(2) = 0.009, P = 0.726); the relationship between age and cervical vertebrae BD was also negatively correlated (r = -0.354, r(2) = 0.13, P = 0.0001). This finding indicates that there is a statistical significance, but that the strength of the relationship is weak (r(2) = 0.13). CONCLUSIONS: There was a correlation between skeletal and mandibular BD, but the strength of the relationship is low. Mandibular BD for both men and women did not correlate with age; cervical vertebral BD did correlate with age.

[A rabbit model of cervical spondylosis established by stimulation of wind, cold and dampness].

OBJECTIVE: To make an animal model of cervical spondylosis (arthralgia syndrome type) with stimulation of wind, cold, and dampness. METHODS: Twenty-four 8 months old male New Zealand white rabbits were randomly allocated into four groups: normal control group, light stimulation group, moderate stimulation group and severe stimulation group. The wind speed was 10.8-13.8 m/s, the temperature was (5+/-0.5)degrees centigrade, and the humidity was 100%. The rabbits of light, moderate, and severe stimulation groups were kept in the above-mentioned environments for 4 hours everyday, and for a total of 32, 64, and 128 hours, respectively. The intervertebral discs were stained with HE method, and observed with a light microscope. Prostaglandin E(2) (PGE(2)), 6-ketone-prostaglandin F1alpha (6-K-PGF(1alpha)) and thromboxane B(2) (TXB(2)) contents were measured by ELISA. Fas and Bcl-2 expressions were examined by immunohistochemical avidin-biotin peroxidose complex technique. Interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and transforming growth factor beta (TGF-beta) mRNA expressions were examined by reverse transcription-polymerase chain reaction. RESULTS: The nucleus pulposus of rabbits in the light and moderate stimulation groups shrunken, and in the severe stimulation group, the anulus fibrosus loosed or ruptured, and the cartilage end-plate became proliferated. Compared with rabbits in the normal control group, the PGE(2) content rose in the light stimulation group, the contents of PGE(2), 6-K-PGF(1alpha), and TXB(2) increased, the expressions of IL-1beta and TNF-alpha mRNAs and Fas were up-regulated, and the expressions of TGF-beta mRNA and Bcl-2 were down-regulated in the moderate and severe stimulation groups. The expression of Fas was up-regulated mostly and Bcl-2 was down-regulated mostly in the severe group. CONCLUSION: Moderate and severe stimulations of wind, cold and dampness can lead to degeneration of cervical intervertebral discs of rabbits. The model corresponds to the theory of traditional Chinese medicine about arthralgia syndrome caused by wind, cold and dampness.

Correlation of postmortem 9.4 tesla magnetic resonance imaging and immunohistopathology of the human thoracic spinal cord 7 months after traumatic cervical spine injury.

OBJECTIVE: To correlate high-resolution magnetic resonance imaging (MRI) with immunohistopathology in the injured human spinal cord. METHODS: Postmortem MRI scans at a field strength of 9.4 T, as well as standard histology and immunohistochemistry, were performed on an excised specimen of human high thoracic spinal cord, obtained 7 months after the initial trauma, several segments below a severe spinal cord lesion (C5). RESULTS: A precise correlation is described between MRI and immunohistochemistry of the long white matter tracts undergoing Wallerian degeneration and of an extension of the cervical lesion into the high thoracic cord. CONCLUSION: MRI, the only imaging technique that currently provides useful information on the spinal cord parenchyma after trauma, is rapidly evolving. High-field scanners of up to 9.4 T are being clinically tested. The present postmortem investigation of an isolated spinal cord specimen demonstrates the precise correlation that can be achieved between imaging and pathology. In future investigations, this type of technique can lead to a more precise description of spinal cord injuries and their consequences in remote tissue. Translation into the clinical setting will improve diagnosis and follow-up of spinal cord injured patients.