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Background Diabetes mellitus (DM) causes bone dysfunction due to poor bone quality and leads to severe deterioration of quality of life. The mechanisms of bone metabolism in DM remain unclear, although chemical and/or mechanical factors are known to disrupt the homeostasis of osteoblasts and osteoclasts. The purpose of this study was to identify the biochemical characteristics of osteoblasts and osteoclasts, using a mouse fracture model of long-term hyperglycemia (LT-HG).Methods C57BL/6J mice and green fluorescent protein (GFP)-positive bone marrow transplanted C57BL/6J mice with LT-HG in which hyperglycemia was maintained for 2 months were used in this study. After the experimental fracture, we examined the immunohistochemical expression of proinsulin and tumor necrosis factor (TNF) -α at the fracture site. C57BL/6J fracture model mice without hyperglycemia were used as the control sample.Results In the LT-HG mice, osteoblasts showed an irregular arrangement at the fracture site. The osteoclasts were scattered with a decrement in the number of nuclei. The positive expression of proinsulin was seen in mesenchymal stem cells (MSCs) with neovascularization 2 and 3 weeks after fracture. Immunopositivity for TNF-α was seen in immature chondrocytes or MSCs with neovascularization at 2 weeks, and the number of positive cells was not decreased at 3 weeks. Examination of GFP-grafted hyperglycemic mice showed that the majority of cells at the fracture site were GFP-positive. Immunohistochemistry showed that the rate of double positives was 15% for GFP and proinsulin and 47% for GFP and TNF-α.Conclusion LT-HG induced an increase in the number of proinsulin and TNF-α positive cells derived from systemic bone marrow cells. The proinsulin and TNF-α positive cells cause both bone formation and bone resorption, and they suppress inflammatory cytokines and impair glucose metabolism.

Background The beta angle (β-angle)—although used to assess femoroacetabular impingement (FAI)—has not been well evaluated. This study aimed to measure the β-angle on multiradial computed tomography (CT) slice images of both hips with symptomatic FAI and asymptomatic normal hips to determine its optimal cutoff value for detecting FAI in a Japanese population. Methods CT was performed with each subject supine. The β-angle was measured on seven radial slices (designated R0, R15, R30, R45, R60, R75, R90) that were generated at 15° intervals from the oblique axial slice through the center of the femoral neck. An a priori power analysis was performed. The measurements were made in 20 FAI hips (FAI group) and 23 asymptomatic normal hips (ANH group). Cutoff values were evaluated using receiver operating characteristic curves. Results The mean β-angles of the FAI and ANH groups at R0, R15, R30, R45, R60, R75, and R90° were, respectively, 73.6° and 84.2°, 66.0° and 79.3°, 57.2° and 69.2°, 48.1° and 63.1°, 46.7° and 62.5°, 50.0° and 63.7°, and 53.7° and 65.9°. For all slices, the β-angle was significantly smaller in the FAI group than the ANH group. The optimal β-angle cutoff values for diagnosing FAI at R0, R15, R30, R45, R60, R75, and R90 were 73.9°, 70.2°, 61.4°, 55.7°, 53.6°, 59.4°, and 60.9°, respectively. The respective specificities and sensitivities of the cutoff values at R0, R15, R30, R45, R60, R75, and R90 were 78.3% and 65.0%, 82.6% and 70.0%, 73.9% and 60.0%, 73.9% and 75.0%, 95.7% and 75.0%, 69.6% and 95.0%, and 78.3% and 80.0%. Conclusions In all radial slices, the β-angle was significantly smaller in the hips with symptomatic FAI than in the asymptomatic normal hips. The most useful cutoff value for diagnosing FAI was a β-angle of 53.6° at R60.

Histological, immunohistochemical, and suspension array analyses of cytokine expression in human cervical ossification of the posterior longitudinal ligament (OPLL).The aim of this study was to determine whether changes in the cytokine profile reflect the maturation of chondrocytes and osteoblasts are associated with OPLL development.OPLL progresses gradually over a prolonged period and may lead to serious spinal cord complications. However, treatment methods only include conservative therapy for neurological symptoms or surgical decompression, whereas preventive therapy for OPLL remains nonexistent.Ligamentous samples were harvested from 24 patients with OPLL who underwent spinal surgery, and five control samples from cervical spondylotic myelo/radiculopathy patients without OPLL. Tissue sections were used for immunohistochemical studies and primary cells were cultured from the ligamentous samples for cytokine profiling. Using a suspension array system, concentrations of 27 inflammatory cytokines or growth factors were measured to generate the cytokine profiles.Suspension array and immunoblot analysis revealed significant increments in the levels of interleukin (IL)-6, IL-1α, basic fibroblast growth factor, and RANTES in patients with OPLL. Immunohistochemical analysis further revealed that these factors were present in mesenchymal cells within the degenerative portion of the ligamentous matrix.Our findings suggest that specific changes in the cytokine profile during ossification promote osteoblast differentiation, thereby providing new insights into OPLL pathogenesis. Moreover, this work supports the development of a new therapeutic method for preventing OPLL progression by regulating the cytokine profiles.Level of Evidence: 3.

Ischiofemoral space (IFS) is a radiological parameter employed for diagnosing ischiofemoral impingement (IFI). The mean IFS value measured with the leg in natural resting position has been reported as 23.0 mm in males and 18.6 mm in females in a patients-based Western population. The normal value of IFS for an Asian population is unknown. This study therefore aimed to investigate whether the IFS value in Japanese hip joints equals that of the Western population. We retrospectively examined 89 consecutive Japanese individuals (178 hips) (46 male subjects with 92 hips, 43 female subjects with 86 hips; mean age 58.7 ± 15.7 years, range 17–84 years) who had undergone computed tomography (CT) for conditions unrelated to hip disorders and ordered by other departments at our institution. All CT scans were performed in a standardized fashion: patient in a flat spine position, hips and knees in extension, and the leg in its natural resting position. IFS was evaluated on axial images as the shortest distance between the ischium and the lesser trochanter. The mean IFSs of this Japanese patient-based population were 20.5 ± 7.3 mm [95% confidence interval (CI) 19.0–22.0] in the male cohort and 13.9 ± 6.5 mm (95% CI 12.6–15.3) in the female cohort. The IFS value was significantly smaller in female subjects than in male subjects. Taking the lower limit of 95% CI into consideration, the IFSs measured in natural leg-resting position in the Japanese male and female groups were significantly smaller than those of the Western populations.

Background The development and etiology of diffuse idiopathic skeletal hyperostosis (DISH) were far from complete understanding. Even the precise mechanism of the development of its typical right-sided ossification of the anterior longitudinal ligament (OALL) frequently compared to ‘flowing candle wax’, a hallmark of DISH, remains unknown. Methods The participants of this study were 261 individuals (31 females and 230 males) diagnosed as DISH according to the criteria established by Resnick and Niwayama extracted from a consecutive 3013 patients who have undergone chest CT for the examination of pulmonary diseases in our institute. The patients with previous thoracic spine surgery and younger than 15 years old were excluded. Chest CT data were converted to the condition suitable for bone evaluation by the software application. The positional relationship between thoracic aorta and OALL, the morphology of the OALL adjacent to the aorta and the presence of calcification of the aortic wall adjacent to the OALL were studied. Results Of 261 individuals with DISH, we found that thoracic aorta was localized adjacent to the OALL (AD-group) in 123 cases (47%), whereas 138 cases (53%) were not (NAD-group). All OALL in AD-group was localized between T6 and T12. The shape of the OALL adjacent to the aorta was either flat or concave except for one. No case showed obvious calcification of the aortic wall adjacent to the OALL in AD-group. Conclusions The aortic pulsation might play an important role in inhibit the development of the OALL toward the aorta in DISH. It is likely that establishment of the optimal condition of the pulsation stress simulating aortic pulsation and its delivery system can achieve arresting, slowing the progression and/or changing the morphology of the ossified lesions.

Objectives:Elderly-onset rheumatoid arthritis (EORA) is reported to differ from young-onset rheumatoid arthritis (YORA) with regard to patient background and drug treatment. We examined the amount of drug administered to patients who achieved low disease activity (LDA) for rheumatoid arthritis at our hospital., Methods:Demographics, clinical history, and treatments were compared between patients with EORA (n = 70) and YORA (n = 190)., Results:There was a significant difference in the average age (73.8 vs. 57.8 years), disease duration (6.66 vs. 14.7 years), and sex (62.9% males vs. 83.7% females), but no difference in rheumatoid factor positivity (85.3% vs. 80.7%), anti-citrullinated peptide antibody positivity (86.5% vs. 87.7%), simplified disease activity index (4.28 vs. 4.59), or disease activity score 28-CRP (1.99 vs. 2.04) in the EORA and YORA groups, respectively. There were also no significant differences in prednisolone use (37.1% vs. 36.3%), amount of methotrexate administered (MTX) (1.45 vs. 1.41 mg), and MTX use (55.7% vs. 65.3%). However, the MTX dose (2.89 vs. 4.09 mg/week, p = .011) and overall biologics use (32.9% vs. 56.3%, p = .0012) were significantly lower in patients with EORA than in those with YORA., Conclusion:Patients with EORA may be able to achieve LDA with lower drug dosage than those with YORA.

Introduction:Posterior lumbar interbody fusion (PLIF) is a widely used effective, safe, and established treatment for degenerative spinal disorders. Adjacent segment disease (ASD) is one of the serious concerns governing the clinical results following spinal fusion surgery. Cortical bone trajectory (CBT) is an alternative and less-invasive technique for lumbar pedicle screw placement. Its unique medial and caudal entry point has the potential to prevent an iatrogenic facet joint violence leading to the ASD; however, the incidence of ASD following PLIF using the CBT technique (CBT-PLIF) remains unknown., Methods:Among patients surgically treated with CBT-PLIF in our institute, 52 consecutive patients (13 males, 39 females) with single-level degenerative lumbar spondylolisthesis (DLS) who were followed up for at least 24 months were exclusively enrolled. Their clinical and radiological features, including the incidence of radiographical and symptomatic ASD and significantly associated factor for the developing radiographical ASD, were retrospectively measured., Results:In the present study, we could confirm significant neurological improvement and reduction of the spondylolisthesis with mean follow-up period of 43 months. Radiographical and symptomatic ASD was observed in 14 (27%) and 2 (3.8%) cases, respectively. We compared these two groups and found that the latest lumbar lordosis was significantly different between the two groups, but not in age, body mass index, and Japan Orthopaedic Association score. Two patients with symptomatic ASD required additional surgical treatment around 1 year following the initial surgery., Conclusions:The present study, even though it is preliminary, revealed that CBT-PLIF can achieve a neurological improvement and an effective reduction of spondylolisthesis for the treatment of single-level DLS. The CBT technique is capable of reducing the incidence of ASD compared with the traditional technique; however, we must keep in mind that appropriate postoperative lumbar lordosis should be achieved. Larger, longer-term follow-up studies are required to elucidate the clinical output of CBT-PLIF.

The pathomechanisms of initiation and progression of ossification of the posterior longitudinal ligament (OPLL) are unclear. Indian hedgehog (Ihh) and related signaling molecules are key factors in normal enchondral ossification. The purpose of this study is to investigate the contribution of mechanical strain to OPLL and the relationship of Ihh with OPLL. Sections of the posterior longitudinal ligament (PLL) were obtained from 49 patients with OPLL and from 7 patients without OPLL. Cultured PLL cells were subjected to 24 hours of cyclic tensile strain. To identify differentially expressed genes associated with cyclic tensile strain, microarray analysis was performed. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified upregulation of various genes, particularly of the Hedgehog signaling pathway; Ihh and related genes had increased expression compared with controls after 24-hour cyclic tensile strain. In immunoblotting analysis, Ihh, Runx2, Sox9, Gli2, Gli3, and smoothened (SMO) had significantly increased expression after 6- or 12-hour cyclic tensile strain. OPLL samples were strongly immunopositive for Ihh, Sox9, Runx2, Gli2, Gli3, and SMO in the ossification front of OPLL. These results suggest that cyclic tensile strain induces abnormal activation of Ihh and related signaling molecules, and this might be important in the ossification process in OPLL.

Background: Recent advancements in treatment of rheumatoid arthritis (RA) with disease-modifying anti-rheumatic drugs (DMARDs) have been remarkable, with disease symptoms nearly disappearing due to their strong anti-inflammatory action and many patients achieving remission. As a result, the need for RA-related surgery has shown a yearly decreasing trend, especially knee surgery and synovectomy procedures [1]. On the other hand, cases of secondary osteoarthritis (OA) in knee joints as a symptom associated with RA following a total knee arthroplasty (TKA) are increasing. Objectives: We investigated the morphology of osteophytes by quantitatively evaluating their size using images obtained prior to performing a TKA. Additionally, the relationships of osteophyte size with patient background, disease activity, and degree of inflammation were examined. Methods: Radiographs of 35 consecutive knees in 30 RA patients (26 females, 4 males; mean age 63.0 years; median disease duration 15 years) who underwent TKA, including preoperative standing AP view radiographs of the knee joint, were retrospectively analyzed. Using the Image-J software package, osteophyte size in the medial femur (MF), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions was determined. Written informed consent for data collection was obtained from all patients in accordance with the Declaration of Helsinki. Results: Preoperative Larsen grade was 2, 3, 4, and 5 in 1, 12, 18, and 2 patients, respectively, while the mean range of motion of the knee joint was 118° for flexion and -10° for extension. The mean femorotibial angle (FTA) was 178±13.6°, with varus (FTA >180°, n=14) more frequently observed as compared to valgus (FTA Conclusion: Our results suggest that secondary OA is a more prominent symptom in RA patients in whom inflammation is controlled, while disease activity has effects on osteophyte size. Reference: [1] Momohara S, Ikari K, Mochizuki T, et al: Declining use of synovectomy surgery for patients with rheumatoid arthritis in Japan. Ann Rheum Dis 2009;68:291-2. Disclosure of Interests: None declared

PURPOSE:Rheumatoid arthritis (RA) patients with secondary osteoarthritis (OA) in a knee joint following a total knee arthroplasty (TKA) procedure have been increasing. Here, we investigated osteophyte formation in knee joints of RA patients and associated factors., METHODS:We retrospectively examined findings of 35 knees in 30 RA patients (26 females, 4 males; mean age: 63.0 years; median disease duration: 15 years) who underwent TKA, including preoperative anteroposterior view radiographs of the knee joint. Using the ImageJ software package, osteophyte size in the medial femur (MF), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions was also determined., RESULTS:The mean femorotibial angle was 179°, while Larsen grade was 2 in 1, 3 in 12, 4 in 18, and 5 in 2 patients. Osteophyte sizes in the MF, MT, LF, and LT regions were 37.2, 17.0, 27.2, and 4.57 mm2, respectively, and significantly greater in the medial compartment (MC; MF+MT) than the lateral compartment (LC; LF+LT) (p < 0.001). In varus cases, osteophyte size in the MC was significantly larger than normal and valgus cases (p = 0.0016). Furthermore, osteophyte size in the MC was negatively correlated with the inflammatory markers C-reactive protein (r = -0.492, p = 0.0027) and erythrocyte sedimentation rate (r = -0.529, p = 0.0016), whereas that in the LC was negatively correlated with disease activity (r = -0.589, p = 0.0023)., CONCLUSION:Our results suggest that alignment and disease activity influence osteophyte formation in RA patients, with secondary OA a more prominent symptom in RA patients with controlled inflammation.

Ossification of the posterior longitudinal ligament or the ligamentum flavum parallels endochondral ossification. Cell differentiation at the ossification front is known to be important during this process, although the factors regulating its initiation and progression are still unclear. The purpose of this study was to identify factors important for the regulation of chondrocyte/osteoblast differentiation during spinal ossification.Ligamentum flavum tissue was isolated from 25 patients who underwent decompressive surgery for cervical ossification of the posterior longitudinal ligament. Tissue sections were used for in vitro culture to obtain primary cells through migration methods. To identify microRNAs associated with ossification of the posterior longitudinal ligament, cultured cells were prepared from the ligamentous tissue (n = 4; continuous type) or from control ligamentous samples harvested from patients with cervical spondylosis without spinal ossification, and analyzed using a microRNA array. The ligamentous sections were also examined by immunohistochemistry for the expression of candidate microRNA target genes.The microRNA array identified 177 factors; 12 of which were expressed at significantly different levels in patients with ossification of the posterior longitudinal ligament compared to those in control patients. The hsa-miR-487b-3p was down-regulated in patients with ossification of the posterior longitudinal ligament, which met the false discovery rate of0.05. This microRNA was predicted to regulate the expression of genes involved in Wnt signaling. Furthermore, immunohistochemistry of Wnt signaling proteins, including Wnt 3a, LRP5/6, and beta-catenin, revealed positive expression in mesenchymal cells and/or premature chondrocytes at the ossification front.Our results suggested that down-regulation of miR-487b-3p plays an important role in the initiation of Wnt signaling during the ossification process. Wnt signaling may regulate both chondrocyte and osteoblast differentiation and the specification of endochondral ossification in the pathogenesis of ossification of the posterior longitudinal ligament or the ligamentum flavum.

Study Design. Histological, immunohistochemical, and immunoblot analyses of the expression of Indian hedgehog (Ihh) signaling in human cervical ossification of the posterior longitudinal ligament (OPLL). Objective. To examine the hypothesis that Ihh signaling in correlation with Sox9 and parathyroid-related peptide hormone (PTHrP) facilitates chondrocyte differentiation in enchondral ossification process in human cervical OPLL. Summary of Background Data. In enchondral ossification, certain transcriptional factors regulate cell differentiation. OPLL is characterized by overexpression of these factors and disturbance of the normal cell differentiation process. Ihh signaling is essential for enchondral ossification, especially in chondrocyte hypertrophy. Methods. Samples of ossified ligaments were harvested from 45 patients who underwent anterior cervical decompressive surgery for symptomatic OPLL, and 6 control samples from patients with cervical spondylotic myelopathy/radiculopathy without OPLL. The harvested sections were stained with hematoxylin-eosin and toluidine blue, examined by transmission electron microscopy, and immunohistochemically stained for Ihh, PTHrP, Sox9, type X, XI collagen, and alkaline phosphatase. Immunoblot analysis was performed in cultured cells derived from the posterior longitudinal ligaments in the vicinity of the ossified plaque and examined for the expression of these factors. Results. The ossification front in OPLL contained chondrocytes at various differentiation stages, including proliferating chondrocytes in fibrocartilaginous area, hypertrophic chondrocytes around the calcification front, and apoptotic chondrocytes near the ossified area. Immunoreactivity for Ihh and Sox9 was evident in proliferating chondrocytes and was strongly positive for PTHrP in hypertrophic chondrocytes. Mesenchymal cells with blood vessel formation were positive for Ihh, PTHrP, and Sox9. Cultured cells from OPLL tissues expressed significantly higher levels of Ihh, PTHrP, and Sox9 than those in non-OPLL cells. Conclusion. Our results indicated that overexpression of Ihh signaling promotes abnormal chondrocyte differentiation in enchondral ossification and enhances bone formation in OPLL.

We have designed a proximal-fitting, anterolaterally flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; KYOCERA Medical, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis, using a nonlinear three-dimensional finite element analysis simulating loading conditions. The Anatomic Fit stem was modified in the region of the arc-sprayed surface, to allow more proximal appearance of spot welds. The aim of the present study was to analyze the clinical and radiographic outcomes of patients who underwent THA using this stem. We reviewed 73 consecutive patients (79 hips; 13 men 16 hips; 60 women 63 hips; age at surgery, 57.6 years, range, 35-78) who underwent cementless THA using the Anatomic Fit stem, at a follow-up period of 7.1 years (range, 5.1-9.4). Harris Hip score improved from 40.7 ± 17.1 before surgery to 91.0 ± 5.2 points at follow-up. The 7.1-year stem survival rate was 100%. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0°. The Anatomic Fit stem provided excellent results. The nonlinear three-dimensional finite element analysis demonstrated that the stem-bone relative motion was 10 µm at the proximal end of the stem and proximal load transfer. Our analysis confirmed reduced radiolucency around the stem, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal.

This report describes case series of the femoral head fractures associated with fracture-dislocation of the hip joint to evaluate the mid- and long-term outcomes and to highlight the surgical technique of fixation of the femoral head from the posterior trochanteric flip osteotomy approach. Twelve patients (6 men and 6 women) with dislocated femoral head fractures (mean age at the time of injury, 56 years; range, 23-80) were followed up for mean period of 9.7 years (range, 5-20). All dislocations were reduced within less than 6 h after the injury. The type of femoral head fracture was classified according to the Pipkin classification on radiographs and CT. Five patients were classified as type I, 2 as type II, 2 as type III, and 3 as type IV. The clinical and radiological outcomes were assessed by Thompson and Epstein's regimen. Excluding 2 patients with Pipkin type III, the outcome of 9 patients was excellent/good, and poor in 1. The latter patient sustained Pipkin type IV and developed osteoarthritis 1 year after surgery and consequently required total hip arthroplasty. We conclude that small fragment of the femoral head less than 1 cm can be removed, while larger fragments should be fixed by bioabsorbable screws or pins in all types of femoral head fractures. In Pipkin type IV fractures, surgeons should always take anatomical reduction in the acetabulum into consideration during surgery.

Study design To examine the localization and expression of high-mobility group box-1 (HMGB-1) protein and its receptors after rat spinal cord injury. Objective To elucidate the contribution of HMGB-1 and its receptors as potential candidates in a specific upstream pathway to the proinflammatory response leading to a cascade of secondary tissue damage after spinal cord injury. Summary of background data HMGB-1 was recently characterized as a key cytokine with a potential role in nucleosome formation and regulation of gene transcription. No studies have investigated the role of HMGB-1 in spinal cord injury. Methods Injured thoracic spinal cord from 62 rats aged 8 to 12 weeks and spinal cord from 20 control rats were examined. HMGB-1 was localized by immunofluorescence staining, costaining with cell markers, and by immunoelectron microscopy. The expression of HMGB-1 and its receptors, receptor for advanced glycation end products (RAGE), toll-like receptor (TLR)2, and TLR4 were also examined by immunohistochemistry. Results HMGB-1 expression appeared earlier than that of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in the spinal cord injury rats, with the HMGB-1 produced by both macrophages and neurons. HMGB-1 translocated from nucleus to cytoplasm in some neurons at an early stage after neural injury. Increased expression of HMGB-1, RAGE, and TLRs was observed after injury, and interaction of HMGB-1 with RAGE or TLRs, particularly in macrophage, was confirmed at 3 days after injury. Conclusion Our results demonstrated an earlier onset in the expression of HMGB-1 than in tumor necrosis factor-α, IL-1β, and IL-6 after spinal cord injury. The release of HMGB-1 from neurons and macrophages is mediated through the HMGB-1/RAGE or TLR pathways. HMGB-1 seems to play at least some roles in the proinflammatory cascade originating the secondary damage after the initial spinal cord injury.

Study Design. To examine the effects of a tumor necrosis factor (TNF)-α antagonist (etanercept) on rat spinal cord injury and identify a possible mechanism for its action. Objective. To elucidate the contribution of etanercept to the pathologic cascade in spinal cord injury and its possible suppression of neuronal and oligodendroglial apoptosis. Summary of Background Data. Etanercept has been recently used successfully for treatment of inflammatory disorders. However, only a few studies have examined its role in suppressing neuronal and oligodendroglial apoptosis in spinal cord injury. Methods. Etanercept or saline (control) was administered by intraperitoneal injection 1 hour after thoracic spinal cord injury in rats. The expressions and localizations of TNF-α, TNF receptor 1 (TNFR1), and TNF receptor 2 (TNFR2) were examined by immunoblot and immunohistochemical analyses. Spinal cord tissue damage between saline- and etanercept-treated groups was also compared after hematoxylin-eosin and luxol fast blue (LFB) staining. The Basso-Beattie-Bresnahan (BBB) scale was used to evaluate rat locomotor function after etanercept administration. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells were counted and the immunoreactivity to active caspase-3 and caspase-8 was examined after etanercept administration. Results. Immunoblot and double immunofluorescence staining revealed suppression of TNF-α, TNFR1, and TNFR2 expression after administration of etanercept in the acute phase of spinal cord injury. LFB staining demonstrated potential myelination in the etanercept-treated group from 2 week after spinal cord injury, together with an increased BBB locomotor score. Double immunofluorescence staining showed a significant decrease in TUNEL-positive neurons and oligodendroglia from 12 hour to 1 week in the gray and white matters after etanercept administration. Immunoblot analysis demonstrated overexpression of activated caspase-3 and caspase-8 after spinal cord injury, which was markedly inhibited by etanercept. Conclusion. Our results indicated that etanercept reduces the associated tissue damage of spinal cord injury, improves hindlimb locomotor function, and facilitates myelin regeneration. This positive effect of etanercept on spinal cord injury is probably attributable to the suppression of TNF-α, TNFR1, TNFR2, and activated caspase-3 and caspase-8 overexpressions, and the inhibition of neuronal and oligodendroglial apoptosis.

A lot of studies on the effect of intra-articular injections are clinical, but many questions on the effect of lidocaine to articular chondrocytes remain unanswered. This study was performed to determine the effects of varying concentrations and exposure times of lidocaine on the viability and proteoglycan metabolism of chondrocytes in vitro. Cartilage was obtained from metatarsal joints of adult bovines. Chondrocytes in alginate beads were cultured in medium containing 6% fetal calf serum at 370 mOsmol at cell densities of 4 million cells/ml. They were then cultured for 24 h under 21% oxygen with 0.125, 0.25, 0.5, and 1% lidocaine and without lidocaine as control. The cell viability profile across intact beads was determined by manual counting using fluorescent probes and transmission electron microscopy. Lactate production was measured enzymatically as a marker of energy metabolism. Glycosaminoglycan (GAG) accumulation was measured using a modified dimethylmethylene blue assay. Cell viability decreased in a time- and dose-dependent manner in the concentration range of 0.125–1.0% lidocaine under the confocal microscope. Under the electron microscope, apoptosis increased as the concentration of lidocaine increased. GAG accumulation/tissue volume decreases as the concentration of lidocaine increased. However, GAG produced per million cells and the rate of lactate production per live cell were significantly higher for cells cultured at 0.5 and 1% lidocaine than the control group. Bovine chondrocytes cultured in alginate beads under high oxygen pressure are negatively influenced by increasing concentrations of lidocaine. Cell viability and proteoglycan production (GAG accumulation/tissue volume) decreased as the concentration of lidocaine increased. These data suggest caution in prolonged exposure of cartilage to high concentration lidocaine. Repeated joint injection of lidocaine potentially worsens osteoarthrosis by accelerating cartilage degradation. Therapeutic studies—investigating the results of treatment, Level III.

Study design This study is aimed to investigate the changes of nerve root functions during the straight leg raising (SLR) test in vivo. Objective To investigate the relationship between nerve root movement and the electrophysiological values during an intraoperative SLR test. Summary of background data The SLR test is one of the most significant signs for making a clinical diagnosis of lumbar disc herniation. A recent study showed that intraradicular blood flow apparently decreased during the SLR test in patients with disc herniation. Methods The study included 32 patients who underwent microdiscectomy. During the surgery, the nerve root motion affected by the hernia was observed during the SLR test. The patients' legs were allowed to hang down to the angle at which sciatica had occurred and the change of nerve root action potentials was measured. After removal of the hernia, a similar procedure was repeated. The periradicular specimens collected during surgery were examined by light and electron microscope. Results In all patients intraoperative microscopy revealed that the hernia was adherent to the dura mater of the nerve roots. During the SLR test, the limitation of nerve root movement occurred by periradicular adhesive tissue and amplitude of action potential showed a sharp decrease at the angle that produced sciatica. After removal of the hernia, all the patients showed smooth gliding of the nerve roots during the test, and there was no marked decrease of amplitude. Our data suggest that temporary ischemic changes in the nerve root cause transient conduction disturbances. Pathologic examination showed that the periradicular tissue consisted of the granulation with vascularization and many inflammatory cell infiltrations. Conclusion The presence of periradicular fibrosis will compound the nerve root pain by fixing the nerve in one position, thereby increasing the susceptibility of the nerve root to tension or compression.

Pelvic ring fracture presents with a wide spectrum of clinical status and fracture type that requires multimodal treatment strategy. We report our experience in the treatment of 224 pelvic ring fractures in terms of clinical and radiological findings, mode of treatment, surgical data, and functional outcome at final follow-up. The study subjects were 140 men and 84 women (mean age 58 years, range 8–94). Surgery was conducted in 63 patients, while 161 were treated conservatively. The average follow-up period was 7.1 years (range 1–15). AO-Orthopaedic Trauma Association classification of fracture type, Injury Severity score rating, Rommens and Hessmann’s ambulatory and pain assessment, and radiographic studies were conducted. Conservative treatment was provided in 161 (73%) patients, including simple bed rest with definitive external fixation, skeletal traction, and/or pelvic sling. Of these, 148 patients achieved excellent/good results, but the remaining 13 cases complained of severe pain at the sacroiliac joints caused by malunion or fibrous union of the joint. All 63 (27%) patients who were treated surgically, using most frequently a combination of anterior extraperitoneal and Pfannenstiel approaches, showed excellent/good clinical and radiographic results. Treatment of unstable pelvic ring fracture should be urgent and based on biomechanical and anatomic reconstructive strategy, paying utmost care to associated injuries. A combination of open stabilization of posterior sacroiliac area and anterior fixation of pubic rami and symphysis pubis is recommended for unstable anteroposterior compression, lateral compression, vertical instability, and unilateral or bilateral posterior injuries to the pelvic ring.

Hematoma of the lumbar ligamentum flavum is a very rare cause of sciatica. A 72-year-old man presented with left-sided sciatica and paresthesia of the lateral aspect of his left foot. From CT and MRI findings, he was diagnosed as having a hematoma embedded in the ligamentum flavum, which compressed the dura mater at the L5/S1 disc level. After an adequate surgical field was obtained with a microscope and a Casper retractor, the hematoma of the ligamentum flavum could be excised via a unilateral approach and satisfactory decompression of the cauda equina and nerve roots were obtained.

Resume L’hematome lombaire du ligament jaune est une cause tres rare de sciatique. Un homme de 72 ans a consulte pour une sciatique gauche et des paresthesies touchant le bord lateral du pied gauche. Le scanner et l’IRM ont montre un hematome du ligament jaune a l’origine d’une compression de la dure-mere a hauteur du disque L5-S1. Apres avoir prepare un champ operatoire adapte au moyen d’un microscope et d’un ecarteur Casper, l’hematome du ligament jaune a ete excise par une approche unilaterale et une decompression satisfaisante de la queue de cheval et des racines nerveuses a ete obtenue.

Using a nonlinear three-dimensional finite element analysis simulating loading conditions, we designed a new type of proximal-fitting, anterolaterally-flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; Japan Medical Materials, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis. The aim of the present study was to analyze the clinical and radiographic outcomes of the new stem. We reviewed 143 consecutive patients (164 hips; 13 men, 14 hips; 130 women, 150 hips; age at surgery, 56.6 +/- 7.6 years, mean +/- SD, range, 30-74) who underwent cementless THA using the FMS-anatomic stem at a single institution, with a follow-up period of 7.6 +/- 1.6 years (range, 5.3-11.0). Harris Hip score improved from 46.1 +/- 12.6 before surgery to 90.0 +/- 8.9 points post-THA. The 7.6-year survival rate of the stem was 99.0% after revision for aseptic loosening. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0 degrees . The FMS-anatomic stem provided excellent results in patients with dysplastic hip osteoarthritis. Our analysis confirmed reduced radiolucency around the stem in Gruen zones, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal in our patients.

Entrapment neuropathy is a frequent clinical problem that can be caused by, among other factors, mechanical compression; however, exactly how a compressive force affects the peripheral nerves remains poorly understood. In this study, using a rabbit model of sciatic nerve injury (n=12), we evaluated the time-course of changes in intraneural blood flow, compound nerve action potentials, and functioning of the blood-nerve barrier during graded mechanical compression. Nerve injury was applied using a compressor equipped with a custom-made pressure transducer. Cessation of intraneural blood flow was noted at a mean compressive force of 0.457+/-0.022 N (+/-SEM), and the compound action potential became zero at 0.486+/-0.031 N. Marked extravasation of Evans blue albumin was noted after 20 min of intraneural ischemia. The functional changes induced by compression are likely due to intraneural edema, which could subsequently result in impairment of nerve function. These changes may be critical factors in the development of symptoms associated with nerve compression.

ObjectThe dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG.MethodsTen Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromaticl-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene–related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope.ResultsIn the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E–positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation.ConclusionsThe presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

Phalen's test has been one of the most significant of clinical signs when making a clinical diagnosis of idiopathic carpal tunnel syndrome (CTS). However, it is unknown whether intraneural blood flow changes during Phalen's test in patients with CTS. In this study, an intraoperative Phalen's test was conducted in patients with CTS to observe the changes in intraneural blood flow using a laser Doppler flow meter. During Phalen's test, intraneural blood flow showed a sharp decrease, which lasted for 1 min. Intraneural blood flow decreased by 56.7%-100% (average, 78.0%) in the median nerve relative to the blood flow before the test. At 1 min after completing the test, intraneural blood flow returned to the baseline value. After carpal tunnel release, there was no marked decrease in intraneural blood flow. This study demonstrated that the blood flow in the median nerve is reduced when Phalen's test is performed in vivo.

Object The effects of sagittal kyphotic deformities or mechanical stress on the development of cervical spondylotic myelopathy, or the reduction and fusion of kyphotic sagittal alignment have not been consistently documented. The aim in this study was to determine the effects of kyphotic sagittal alignment of the cervical spine in terms of neurological morbidity and outcome after 2 types of surgical intervention. Methods The authors retrospectively reviewed the records of 476 patients who underwent cervical spine surgeries for spondylotic myelopathy between 1993 and 2006 at their university medical center. Among these were identified 43 patients—30 men and 13 women, with a mean age of 58.8 years—who had cervical kyphosis exceeding 10° on preoperative sagittal lateral radiographs obtained in the neutral position, and their cases were analyzed in this study. Anterior decompression with interbody fusion was conducted in 28 patients, and en bloc open-door C3–7 laminoplasty in 15 patients. Both pre- and postoperative neurological, radiographic, and MR imaging findings were assessed in both surgical groups. Results The mean preoperative kyphotic angle in all 43 patients was 15.9 ± 5.9° in the neutral position. Segmental instability was noted in 26 patients (61%) and reversed dynamic spinal canal stenosis at the level above the local kyphosis in 22 (51%). Preoperative T2-weighted MR images showed high-intensity signal within the cord at and around the level of maximal compression or segmental instability in 28 patients (65%). The mean kyphotic angle in both the neutral and flexion positions was significantly smaller at 4–6 weeks after surgery in the anterior spondylectomy group than in the laminoplasty group (p < 0.001). Furthermore, the angle in the neutral position was significantly smaller on follow-up in the anterior spondylectomy group than in the laminoplasty group (p = 0.034). The transverse area of the spinal cord was significantly larger in the anterior spondylectomy group than in the laminoplasty group on follow-up (p = 0.037). Preoperative neurological scores (assessed using the Japanese Orthopaedic Association scale) and improvement on follow-up ≥ 2 years after treatment (average 3.3 years) were not significantly different between the 2 groups; however, there was a significant difference in Japanese Orthopaedic Association score at 4–6 weeks postoperatively (p = 0.047). Conclusions Kyphotic deformity and mechanical stress in the cervical spine may play an important role in neurological dysfunction. In a select group of patients with kyphotic deformity ≥ 10°, adequate correction of local sagittal alignment may help to maximize the chance of neurological improvement.

Dumb-bell tumours often require extended resection of osseous structures of the spine and subsequent anterior and/or posterior stabilization. Minimally addressed microsurgical intraneural extracapsular resection of a neurinoma originating from around the neuroforamen often provides immediate benefits. We describe our experience with microsurgical intraneural extracapsular resection of four cervical dumb-bell neurinomas in four patients. After a 4- to 7-cm skin incision, a small resection of the laminae and neuroforamen allowed visualisation of the tumour. The procedure was followed by microsurgical intraneural extracapsular complete "enucleation" resection of the tumour, without sacrificing motor funiculi or causing damage to surrounding arteries and radicular veins. One patient had a giant neurinoma at the C5-C6 and C6-C7 foraminal levels that required simultaneous anterior fusion at C5-C6 level only. The average blood loss during surgery was 35 mL (range: 11-59) and all showed neurological improvement immediately after surgery. Minimally addressed microsurgical intraneural extracapsular "enucleating" resection of tumours around the neuroforamen may be beneficial for patients, is not associated with vascular morbidity, and avoids the subsequent need for extensive spinal instrumentation.

Object The aims of this study were to review the clinicoradiological findings in patients who underwent decompressive surgery for proximal and distal types of muscle atrophy caused by cervical spondylosis and to discuss the outcome and techniques of surgical intervention. Methods Fifty-one patients (43 men and 8 women) with proximal (37, with arm drop) and distal muscle atrophy (14, with wrist drop) underwent cervical decompression (39 anterior decompressions and 12 open-door C3–7 laminoplasties with microsurgical foraminotomy) for muscle weakness in the upper extremities. The clinical course, type of spinal cord compression, abnormal signal intensity on high-resolution MR imaging, and postdecompression improvement in muscle power were reviewed at a mean follow-up of 2.6 years (range 0.8–9.4 years). Results The most commonly affected vertebrae were C4–5 and C5–6, and C5–6 and C6–7 in patients with proximal or distal muscle atrophy, respectively; the respective numbers of affected vertebrae were 1.5 and 2.2. Transaxial MR imaging showed medial compression of the spinal cord in 20 patients (in 12 with proximal and 8 with distal muscle atrophy), paramedial compression in 22 (17 and 5 patients, respectively), and foraminal compression in 9 (8 and 1 patient, respectively). Increased signal intensity on MR imaging was observed in 85.0, 22.7, and 11.1% of cases of medial, paramedial, and foraminal compression, respectively. Increased signal intensity at the affected muscle segment level was observed in 52.9, 40.0, and 0% of cases, respectively. Sixty-two percent of patients with proximal muscle atrophy gained 1 or more grades of muscle power on manual muscle testing (MMT), whereas 64.3% with distal muscle atrophy failed to gain even 1 grade of improvement. The recovery of muscle power correlated with disease duration and the percent voltage of Erb point or wrist-stimulated muscle evoked potentials but not with preoperative MMT, longitudinal range of spinal cord compression, signal change on T2-weighted MR imaging, or surgical procedure. Conclusions Surgical outcome in patients with distal muscle atrophy was inferior to that in patients with proximal atrophy. The distal type was characterized by a long preoperative period, a greater number of cervical spine misalignments, a narrow spinal canal, and increased signal intensity on T2-weighted MR imaging. It is essential to perform a careful neurological evaluation, including sensory examination of the lower limbs, as well as neuroradiological and neurophysiological assessments to avoid confusion with motor neuron disease and to detect the coexistence of amyotrophic lateral sclerosis, especially when surgical treatment of cervical spondylosis is planned. The results of careful physical examination, MR imaging studies, and electromyography studies should be comprehensively evaluated to ascertain the pathophysiology of the muscle atrophy. It is very important to distinguish the pathophysiology caused by nerve root impingements from anterior horn dysfunction when making decisions about treatment strategy. Surgical treatment—with or without foraminotomy—for amyotrophy in cervical spondylosis requires urgent action with regard to human neuroanatomy and neural innervation of the paralyzed muscles.

Molecular biological techniques such as the polymerase chain reaction (PCR) and DNA microarray are used for the detection/identification of microorganisms; however, few reports have discussed the clinical utility of microarray analysis for identification of causative organisms of osteoarticular infections. It is important to examine the utility of PCR amplification followed by analysis of DNA microarray carrying specific oligonucleotides.This study included 101 biological samples obtained from 96 patients who underwent conservative and/or surgical treatment for osteoarticular infections. In this double-blind comparative study, routine conventional testing and the research groups were unaware of each other's interpretation until identical specimens were identified by culture and microarray analysis.Results of PCR microarray analysis were positive for 25 samples and negative for the remaining 76 samples within 24 h, and the results of the cultures (available after a mean of 3.54 days) were positive in 26 samples and negative for the remaining 75 samples. The sensitivity of microarray analysis was 84.6% (22/26) and specificity was 88.0% (22/25). Discrepant results were identified in seven samples, including a negative culture and a positive microarray in three cases and a positive culture and a negative microarray in four other cases.The PCR microarray analysis is complementary to routine cultures in identifying causative microorganisms and should be used in patients with highly suspected infections and negative bacterial culture and in patients who require prompt diagnosis and early initiation of antibiotic therapy.

A 58-year-old woman with an insignificant stage of diabetes mellitus presented with rapidly progressive osteoarthritis of her right knee exhibiting painless but significant antero-posterior and lateral instability. In association, she had a huge extruded left-sided cervical intervertebral disc at the C4-5 level. Neurological examination of the upper limbs was normal but, she had diminished pinprick sensation on the right leg. Radiographic findings were consistent with neuropathic arthropathy of the knee. Anterior decompression with fusion of C4-5 and total knee arthroplasty using a semi-constrained-type artificial implant were performed in one stage. The patient regained nearly normal living activity following surgical intervention. We stress the possibility of rapid progression of knee joint arthropathy, as neuropathic knee, even in a patient with less significant symptoms and signs of cervical myelopathy caused by a huge extruded intervertebral disc.

Study Design. Evaluation of cervical spinal cord (CSC) of patients with compressive myelopathy by magnetic resonance imaging (MRI) and high-resolution ( 18 F)fluoro-deoxyglucose ( 18 FDG) positron emission tomography (PET). Objective. To determine changes in morphology, intramedullary signal intensity, and glucose metabolic rate in CSC after decompression, and to assess the utility of 18 FDG-PET in evaluation of patients with cervical myelopathy. Summary of Background Data. The significance of CSC enlargement after decompression and signal intensity changes within the cord remain elusive. No data are available on metabolic activity of the compressed CSC. Only a few studies have examined correlation between high-resolution MRI and 18 FDG-PET neuroimaging in cervical myelopathy. Methods. We studied 24 patients who underwent cervical decompressive surgery in terms of postoperative neurologic improvement and changes in MRI and 18 FDG-PET. Neurologic status was assessed by the Japanese Orthopedic Association scoring system (17-point scale). Signal intensity change in the cord was qualitatively assessed on both T1- and T2-weighted images. The transverse area of the CSC on MRIs and glucose metabolic rate (standardized uptake value [SUV]) from 18 FDG-PET were measured digitally. Results. Neurologic improvement correlated with preoperative CSC transverse area at maximal compression (P < 0.01) and at follow-up (P < 0.001) and with mean SUV before surgery (P< 0.01) and at follow-up (P< 0.05). Preoperative signal intensity change on MRIs (low intramedullary signal intensity abnormality on T1-weighted image and high intramedullary on T2-weighted image) correlated negatively with neurologic improvement rate (P < 0.05). The transverse area of the CSC was significantly smaller after surgery in patients with preoperative MRI signal intensity changes (P < 0.05). The SUV at follow-up tended to normalize in association with neurologic improvement. Conclusion. Our results showed that postoperative neurologic improvement in patients with cervical compressive myelopathy correlated with increased transverse area of the spinal cord, signal intensity change on both T1- and T2-weighted image, and the mean SUV.

STUDY DESIGN: An experimental study to investigate the in vitro gene expression of neurotrophic factors and receptors in cultured rat spinal cord cells subjected to cyclic mechanical stretch forces. OBJECTIVE: We evaluated in vitro expression of neurotrophic factors and receptors in cultured rat spinal cord cells under cyclic tensile stress. SUMMARY OF BACKGROUND DATA: Application of compressive mechanical stress to the spinal cord results in multiple changes making it difficult to examine the expression of neurotrophic factors and their receptors. There are no in vitro studies that investigated the biologic responses of cultured spinal cord cells to tensile stress. METHODS: Spinal cord cells were isolated for culture from 15-day Sprague-Dawley rat embryos. We used the FX3000 Flexercell Strain Unit to induce mechanical stress. We analyzed the effects of mechanical stress on cell morphology, mRNA expression levels of various neurotrophic factors, and their immunoreactivities at 0, 2, 6, 12, 24, and 36 hours. RESULTS: Tensile stress for 6 hours resulted in reduction of spinal cord cells and loss of neurites. Cells that survived 24-hours stress showed swollen irregular-shaped soma, bleb formation, and fragmented neurites. The cell survival rate decreased, whereas lactate dehydrogenase release increased significantly at 6 hours. There were significant increases in mRNA expression levels of nerve growth factor, brain-derived neurotrophic factor, trkB, p75 neurotrophin receptor (p75), glial cell line-derived neurotrophic factor, and caspase-9 during the early period after application of tensile stress. CONCLUSION: Our results suggest survival of spinal cord neuronal cells under injurious tensile stress with increased synthesis and utilization of several neurotrophic factors, receptors, and expression of proteins related to cell apoptosis.

The development of radiculopathy in patients with lumbar canal stenosis is thought to be closely related to intraradicular edema resulting from compression. However, there is little agreement as to question which is more essential for intermittent claudication: ischemia or congestion. The aim of the present experimental investigation was to examine the effect of ischemia and congestion on the nerve root using dogs. The aorta was clamped as an ischemia model of the nerve root and the inferior vena cava was clamped as a congestion model at the sixth costal level for 30 min using forceps transpleurally. Measurements of blood flow, partial oxygen pressure, and conduction velocity in the nerve root were repeated over a period of 1 h after release of clamping. Finally, we examined the status of intraradicular blood-nerve barrier under fluorescence and transmission electron microscope. Immediately after clamping of the inferior vena cava, the central venous pressure increased by about four times and marked extravasation of protein tracers was induced in the lumbar nerve root. Blood flow, partial oxygen pressure, and conduction velocity of the nerve root were more severely affected by aorta clamp, but this ischemia model did not show any intraradicular edema. The blood-nerve barrier in the nerve root was more easily broken by venous congestion than by arterial ishemia. In conclusion, venous congestion may be an essential factor precipitating circulatory disturbance in compressed nerve roots and inducing neurogenic intermittent claudication.

Study design This study was aimed at investigating changes in the dorsal horn of the lumbar cord induced by mechanical compression using an in vivo model. Objective To determine the effect of axonal flow disturbance in the dorsal horns induced by nerve root compression. Summary of background data Few studies have looked at changes of synapses within the dorsal horn caused by disturbance of axonal flow and the axon reaction as a result of mechanical compression of the dorsal root. Methods In mongrel dogs, the 7th lumbar nerve root was compressed for 1 week, or 3 weeks using a clip. After intravenous injection of Evans blue albumin, they were observed under a fluorescence microscope for the purpose of clarifying the function of the blood-spinal cord barrier. Morphologic changes of the synapses in the dorsal horns secondary to the nerve fiber degeneration were examined by light and electron microscope. Changes on immuno-staining for substance P, calcitonin gene-related peptide, and somatostatin in the dorsal horn were also examined. Results Light microscope observation conducted 1 week after compression of the nerve roots revealed Wallerian degeneration of the myelinated nerve in the dorsal horn, and fluorescence microscope observation of these areas demonstrated edema formation resulting from damage of the blood-spinal cord barrier. Three weeks after the compression, electron microscope observation revealed shrinkage of the axon terminals, ubiquitous presence of high electron density degeneration and presence of synapses whose contact with synapses was disrupted. Immuno-histochemical studies showed a marked decrease of substance P, calcitonin gene-related peptide, and somatostatin staining in substance gelatinosa with Wallerian degeneration after compression of nerve root. Conclusion It is important to recognize that compressive disturbance of the nerve roots caused Wallerian degeneration not only at the site of compression of nerve roots but also at the synapses of spinal cord dorsal horns.

Targeted retrograde gene delivery into the injured spinal cord is less invasive for the damaged tissue. One of the advantages of this approach is the possible selection of target organs according to the level of spinal cord injury. We evaluated nine candidate target organs for retrograde delivery of an adenovirus vector carrying β-galactosidase (AdV-LacZ) gene to cervical, thoracic and lumbar spinal cord segments. One week after vector injection into each muscle, we assessed the LacZ gene expression in the spinal cord by X-gal staining. The most appropriate target organs with high transduction efficacy were the sternomastoid and clavotrapezius muscles for cervical spinal cord, tibialis anterior and the gastrocnemius muscles for the lumbar spinal cord. Retrograde gene delivery to the thoracic spinal cord was inefficient probably due to the small number of anterior horn neurons in the region. Gene expression was mainly identified over the anatomical area of innervation and not into other body organs. Our results suggested that retrograde delivery of adenovirus genome to the cervical and lumbar spinal cord segments seems feasible by injection of an adenoviral vector into the appropriate target organ. Adenovirus vector is an efficient retrograde tracer since it can deliver the carried gene to a wide area of the spinal cord and not to other body organs.

Object In this study, the authors examined how physiological levels of extracellular osmolality influence proteoglycan accumulation in nucleus pulposus cells in a 3D culture system. Methods Cells were isolated from the nucleus pulposus of caudal discs obtained from 18- to 24-month-old bovines. They were cultured for 6 days in alginate beads at 4 million cells/ml in Dulbecco modified Eagle medium containing 6% fetal bovine serum under 21% O2. Medium osmolality was altered by NaCl addition between 270 and 570 mOsm and monitored using a freezing point osmometer. The cell viability profile was determined by manual counting after trypan blue staining. Profiles across intact beads were determined by manual counting by using fluorescent probes and a transmission electron microscope. Lactate production was measured enzymatically, and glycosaminoglycan (GAG) accumulation was measured using a dimethylmethylene blue assay. Rate of sulfate GAG synthesis was measured using a standard [35S]sulfate radioactive method. Results The cell viability was similar for the high- and low-osmolality cultures. However, confocal microscopy showed that the cells were the largest at 270 mOsm and became smaller with increasing osmotic pressure. The GAG production was largest at 370 mOsm, the capacity for GAG production and cell metabolism (lactate production) was low under hypoosmolality and hyperosmolality, and cell death was observed on electron microscopy. Conclusions In the authors' model, the prevailing osmolality was a powerful regulator of GAG accumulation by cultured nucleus cells. Thus, these results indicate that GAG synthesis rates are regulated by GAG concentration, with implications both for the cause of degeneration and for tissue engineering.

We investigated the histological and immunohistochemical features of degenerative changes in the ligamentum flavum of the lumbar spine with calcium crystal deposition. We investigated degenerative changes in 270 ligamentum flavum specimens harvested from 198 patients who underwent decompressive surgeries for lumbar spinal canal stenosis. En bloc sections of the ligamentum flavum were examined histologically. We also examined immunoreactivity for transforming growth factor (TGF)-beta, vascular endothelial growth factor (VEGF), CD34, and CD68; immunoblot analysis for VEGF; and terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling (TUNEL) method. The ligamentum flavum showed fragmented and disorganized elastic fiber bundles with increased collagen fibrils in the matrix. Calcium deposition, which was identified as calcium pyrophosphate dihydrate crystals, was evident in 72 of 198 patients and in 99 of 270 samples, and was associated with appearance of hypertrophic chondrocytes and new blood vessel formation. Areas of calcium deposits were surrounded by abundant hypertrophic chondrocytes (with marked immunoreactivity to TGF-beta and VEGF) and a significant number of TUNEL-positive chondrocytes. Calcium crystal deposition in the lumbar ligamentum flavum progresses with reduction in elastic fibers and accumulation of collagen fibrils in the matrix as well as expansion of chondrometaplastic areas.

Purpose. To describe a technique involving posterior 360-degree stabilisation of the upper thoracic spine: spinal cord decompression, posterior vertebral body replacement, and then posterior instrumentation and intercostal posterolateral vertebral stabilisation. Methods. Three men and 4 women aged 41 to 77 (mean, 58) years underwent posterior 360-degree stabilisation of the upper thoracic spine. Their indications for surgery were bone metastasis (n=5), burst fracture (n=1), and osteoporotic collapse with cord compression (n=1). Their clinical and radiological findings and treatment outcomes were retrospectively reviewed. Results. Pain status of all patients improved after surgery: 4 had severe and 3 had mild pain preoperatively; in 3 pain became minimal and 4 had none postoperatively. All patients except one had Frankel/American Spinal Injury Association scores of E after surgery indicating complete recovery of sensory and motor function. There were no complications related to surgery or instrumentation construct. At the time of review, one patient had died of old age 8.6 years after surgery and another from local recurrence and lung metastasis 5.7 years after surgery. All other patients were living. Conclusion. One-stage posterior 360-degree stabilisation and vertebral body replacement is a useful technique for upper thoracic spine surgery.

Object. The object of this study was to histopathologically and immunohistochemically characterize ossification of the ligamentum flavum (OLF) in samples of the thoracic spine harvested en bloc during surgery and to enhance the understanding of the ossifying process, particularly calcification and ossification. Methods. Samples of OLF plaque were obtained en bloc from 43 patients who underwent posterior decompression. The histopathological findings were correlated with radiological subtypes using computed tomography. The expression of type I and type II collagens, vascular endothelial growth factor (VEGF), transforming growth factor (TGF)β, and bone morphogenetic protein (BMP)–2 was investigated. Results. Surgical decompression using the posterior floating and en bloc resection technique resulted in neurological improvement in 40 of 43 patients. Progression of the OLF lesion longitudinally and medially was associated with significant degeneration of elastic fibers, fiber bundle derangement, decrements in fiber diameter, and fragmentation. Calcification and ossification paralleled the degeneration of the elastic fibers, extended more medially, and fused in the central area. Expression of BMP-2, TGFβ, and VEGF was significant in chondrocytes in the calcified cartilage and fibrocartilage layers, especially around the calcified front. Conclusions. Histopathologically, the progress of calcification and ossification was closely associated with the degeneration of elastic fibers and with significant expression of BMP-2, TGFβ, and VEGF in the ossification front.