古矢 丈雄

Study Design: Retrospective case series. Purpose: To examine the efficacy of platelet-rich plasma (PRP) for bone fusion in transforaminal lumbar interbody fusion (TLIF) using local bone grafting. Overview of Literature: Several authors have reported the efficacy of PRP for bone union in animal models. However, the use of PRP for bone fusion in TLIF surgery has not been fully explored. Methods: Twenty patients underwent single-level TLIF surgery because of L4 spondylolisthesis. An interbody fusion cage and local bone were used in nine patients (control group) and an interbody fusion cage, local bone, and PRP were used in 11 patients (PRP group). PRP was prepared from the patients' blood samples (400 mL) immediately before surgery. The duration of bone union and postoperative bone fusion rate were assessed using plain radiography at every 3 months postoperatively and computed tomography at 12 or 24 months postoperatively, respectively. Lower back pain, leg pain, and leg numbness were evaluated using the visual analog scale preoperatively and at 3, 6, 12, and 24 months postoperatively. Results: The platelet count was 8.7 times higher in PRP than in blood. The bone union rate was significantly superior in the PRP group than in the control group (91% and 77%, respectively; p=0.035), whereas the average duration of bone union was not significantly different between the groups (7.7±0.74 and 10.0±2.00 months, respectively; p=0.131). There was no significant difference in lower back pain, leg pain, and leg numbness in both groups during follow-up (p>0.05). Conclusions: Our study suggests that the use of PRP in TLIF surgery increases bone fusion rate.

© 2017 Wolters Kluwer Health, Inc. All rights reserved. Study Design. A cross-sectional study. Objective. The aim of this study was to quantify spinal cord dysfunction at the tract level in patients with cervical compressive myelopathy (CCM) using reduced field-of-view (rFOV) diffusion tensor imaging (DTI). Summary of Background Data. Although magnetic resonance imaging (MRI) is the standard used for radiological evaluation of CCM, information acquired by MRI does not necessarily reflect the severity of spinal cord disorder. There is a growing interest in developing imaging methods to quantify spinal cord dysfunction. To acquire high-resolution DTI, a new scheme using rFOV has been proposed. Methods. We enrolled 10 healthy volunteers and 20 patients with CCM in this study. The participants were studied using a 3.0-T MRI system. For DTI acquisitions, diffusion-weighted spin-echo rFOV single-shot echo-planar imaging was used. Regions-of-interest (ROI) for the lateral column (LC) and posterior column (PC) tracts were determined on the basis of a map of fractional anisotropy (FA) of the spinal cord and FA values were measured. The FA of patients with CCM was compared with that of healthy controls and correlated with Japanese Orthopaedic Association (JOA) score. Results. In LC and PC tracts, FA values in patients with CCM were significantly lower than in healthy volunteers. Total JOA scores correlated moderately with FA in LC and PC tracts. JOA subscores for motor dysfunction of the lower extremities correlated strongly with FA in LC and PC tracts. Conclusion. It is feasible to evaluate the cervical spinal cord at the tract level using rFOV DTI. Although FA values at the maximum compression level were not well correlated with total JOA scores, they were strongly correlated with JOA subscores for motor dysfunction of the lower extremities. Our findings suggest that FA reflects white matter dysfunction below the maximum compression level and FA can be used as an imaging biomarker of spinal cord dysfunction.

INTRODUCTION: Discogenic back pain remains poorly understood with respect to etiopathogenesis, despite being a considerable burden. We sought to examine the expression of vascular endothelial growth factor in injured intervertebral discs in rat caudal vertebrae. METHODS: Forty-eight male Sprague Dawley rats were assigned to 2 groups according to disc puncture injury: puncture (n = 32) or non-puncture (n = 16). Disc puncture was performed percutaneously such that the incision would be in the primary plane of motion for the coccygeal discs 5-6, 6-7, and 7-8. A 26-gauge needle was used to puncture each disc 10 times. Punctured discs were examined histologically by hematoxylin and eosin staining at 1, 7, 14, and 28 days post-injury. RESULTS: Vascular endothelial growth factor was localized immunohistochemically, and determined quantitatively using an enzyme-linked immunosorbent assay. Peak inflammation occurred on the 7th day post-injury, but tissue degeneration continued until day 28. Local expression of vascular endothelial growth factor tended to be highest in the annulus fibrosus on the 7th and 14th days after puncture injury. The level of vascular endothelial growth factor was highest 1-day post-injury, and then gradually decreased thereafter. Furthermore, vascular endothelial growth factor levels in the puncture group were significantly higher than those in the non-puncture control group (p < 0.05). CONCLUSIONS: We found increased expression of the inflammatory cytokine vascular endothelial growth factor in injured intervertebral discs, suggesting that vascular endothelial growth factor may be clinically important in discogenic back pain.

INTRODUCTION: Osteoporosis and sarcopenia are said to be similar disorders. However, few reports have described the effects of anti-osteoporosis drugs on muscle mass in clinical practice. METHODS: We selected 150 postmenopausal women with osteoporosis treated by minodronate (osteoporosis medication [OM] group) and 50 postmenopausal women without osteoporosis who did not receive treatment (no osteoporosis [NO] group). The OM group was further divided into two treatment subgroups: a combination of monthly minodronate and daily activated vitamin D vs. monthly minodronate alone. We measured lumbar spine and femoral neck bone mineral density (BMD) with dual-energy X-ray absorptiometry and muscle mass of the upper limbs, lower limbs, and trunk with bioelectrical impedance analysis at baseline and after 6 months. RESULTS: The OM and NO groups contained 130 and 37 patients, respectively (mean age: 73.9 ± 8.3 and 74.1 ± 10.0 years, respectively). In the OM group, lumbar spine BMD significantly increased after 6 months, while lower limb muscle mass significantly decreased. In the NO group, lumbar spine BMD and lower limb muscle mass did not significantly change after 6 months. In the OM group, BMD of the lumbar spine significantly increased but the lower limb muscle mass significantly decreased after 6 months relative to the NO group. In the combination therapy subgroup of the OM group muscle mass decreased significantly less than in the minodronate-alone subgroup. CONCLUSIONS: In postmenopausal women with osteoporosis, minodronate can increase BMD but cannot increase muscle mass. However, simultaneous use of activated vitamin D can suppress muscle mass decrease. The combination of activated vitamin D and minodronate may be useful for treating osteoporosis in postmenopausal women.

INTRODUCTION: Osteoporosis can produce a persistent state of pain known as osteoporotic pain. One proposed mechanism of this pathology is increased calcitonin gene-related peptide (CGRP; a marker related to inflammatory pain) expression in the dorsal root ganglia (DRG) innervating osteoporotic vertebrae. Alternatively, a previous study revealed that axial loading caused osteoporotic pain in a rodent model of coccygeal vertebrae compression. Because this compression model is associated with trauma, additional mechanistic studies of osteoporotic pain in the absence of trauma are required. The current study aimedto evaluate the expression and relative distribution of transient receptor potential vanilloid 4 (TRPV4), a pain-related mechanoreceptor, in ovariectomized (OVX) osteoporotic rats. METHODS: CGRP-immunoreactive (-ir) and TRPV4-ir DRG neurons innervating the L3 vertebrae of Sprague-Dawley rats were labeled with a neurotracer, FluoroGold. Intravertebral pH was also measured during the neurotracer procedure. TRPV4-ir/CGRP-ir FluoroGold-positive DRG neurons were quantified in sham control and OVX rats (n = 10, ea). The threshold for statistical significance was set at P < 0.05. RESULTS: There was no statistical difference in the number of FluoroGold-positive DRG neurons between groups; however, there were significantly more CGRP-ir/TRPV4-ir FluoroGold-positive DRG neurons in the OVX group compared with the sham control group (P < 0.05) as well as the significantly increased molecular production of each peptide. Intravertebral pH was also lower in the OVX group compared with the sham control group (P < 0.05). CONCLUSION: Sensory neurons innervating osteoporotic vertebrae exhibited increased expression of co-localized CGRP and TRPV4 in OVX osteoporotic rats. Additionally, intravertebral pH was low in the vicinity osteoporotic vertebrae. Considering that TRPV4 is a mechanosensitive nociceptor that is activated in acidic environments, its upregulation may be associated with the pathology of osteoporotic pain derived from microinflammation involved in osteoporosis.

Background Fall-induced injuries represent a major public health concern for older individuals. The relationship between risk of falling and the severity of locomotive syndrome (LS) remains largely unknown. Methods We conducted a retrospective analysis of patients who had undergone surgery from January 2012 to December 2013 and completed at least 1 year of follow-up at 12 participating institutes. Patients completed a questionnaire survey regarding their fall experience during a routine postoperative follow-up. Questionnaire items included the number of falls during the prior postoperative year and the 25-question Geriatric Locomotive Function Scale (GLFS-25). The severity of cervical myelopathy was assessed using the Japanese Orthopaedic Association (JOA) score. We analyzed the association between the incidence of falling and the severity of LS measured by the GLFS-25. Results Of 360 patients, 61 (16.9%) experienced 1 fall 31 (8.6%), 2–3 falls 4 (1.1%), 4–5 falls and 6 (1.7%), ≥6 falls during the first postoperative year. Thus, 102 (28%) patients experienced at least 1 fall, and 41 (11%) experienced recurrent falls (2 or more falls) during the time period. The mean GLFS-25 score was 30.2 ± 22.7, and 242 (62%) patients had GLFS-25 scores of 16 or higher, which fulfilled the diagnostic criteria for LS. When subjects were categorized into recurrent fallers and non-recurrent fallers, recurrent fallers had a significantly higher GLFS-25 score and a significantly lower extremity motor function score of the JOA score than non-recurrent fallers. The GLFS-25 and lower extremity motor function score of the JOA score yielded the areas under the receiver operating characteristic curves of 0.674 and 0.607, respectively, to differentiate recurrent fallers from non-recurrent fallers. Conclusion Postoperative patients with cervical myelopathy had a 62% prevalence of LS. The GLFS-25 may be useful to predict the risk of recurrent falls in patients with cervical myelopathy.

イバンドロネー卜錠剤を投与した閉経後骨粗鬆症患者60例(平均75.0±7.1歳)を対象に、薬剤継続率、骨粗鬆症改善効果(骨吸収抑制および骨密度上昇)を検討した。薬剤継続率は投与後6ヵ月時点で76.7%(46例)であった。また、副作用発生頻度は11.7%(7例)で、インフルエンザ様症状3例、歯の違和感2例、内服後胃部不快感2例であった。副作用が発生した症例における薬剤継続率は57.1%であった。骨粗鬆症改善効果は、投与前に比べ投与後6ヵ月で骨吸収マーカーTRACP-5b値は有意に低下し、平均腰椎YAM値は有意に増加した。投与6ヵ月による骨密度レスポンス率(骨密度が増加した患者の割合)は95.7%であった。以上、イバンドロネート錠剤の高い薬剤継続率、骨粗鬆症改善効果(骨吸収抑制効果、骨密度上昇効果、骨密度レスポンス率)が示された。

Previously, a rat model of chronic compressive myelopathy that uses a water-absorbing polymer inserted under a spinal lamina was reported. However, the best size and coefficient of expansion of the polymer sheet have not yet been established. The aim of the present study was to optimize these properties in an ideal rat model of cervical compressive myelopathy. Thirty rats were used in this study. A sheet of water-absorbing polymer was inserted under the cervical laminae. Rats were divided randomly into five experimental groups by the expansion rate (350 or 200%) and thickness (0.5 or 0.7mm) and the control. After the surgery, the severity of paralysis was evaluated for 12 weeks. At 12 weeks after the surgery, cresyl violet staining was performed to assess the number of motor neurons in the anterior horn at the C4/C5 segment and Luxol Fast Blue staining was performed to assess demyelination in the corticospinal tract at the C7 segment. Slow-progressive' paralysis appeared at 4-8 weeks postoperatively in rat models using sheets with 200% expansion. By contrast, only temporary paralysis was observed in rat models using sheets with 350% expansion. A loss of motor neurons in the anterior horn was observed in all groups, except for the control. Demyelination in the corticospinal tract was observed in rat models using sheets with 200% expansion, but not rat models using sheets with 350% expansion. A polymer sheet that expands its volume by 200% is an ideal material for rat models of cervical compressive myelopathy.

Recently, lateral interbody fusion (LIF) has become more prevalent, and evaluation of lumbar nerves has taken on new importance. We report on the assessment of anatomical relationships between lumbar nerves and vertebral bodies using diffusion tensor imaging (DTI). Fifty patients with degenerative lumbar disease and ten healthy subjects underwent DTI. In patients with lumbar degenerative disease, we studied nerve courses with patients in the supine positions and with hips flexed. In healthy subjects, we evaluated nerve courses in three different positions: supine with hips flexed (the standard position for MRI); supine with hips extended; and the right lateral decubitus position with hips flexed. In conjunction with tractography from L3 to L5 using T2-weighted sagittal imaging, the vertebral body anteroposterior span was divided into four equally wide zones, with six total zones defined, including an anterior and a posterior zone (zone A, zones 1-4, zone P). We used this to characterize nerve courses at disc levels L3/4, L4/5, and L5/S1. In patients with degenerative lumbar disease, in the supine position with hips flexed, all lumbar nerve roots were located posterior to the vertebral body centers in L3/4 and L4/5. In healthy individuals, the L3/4 nerve courses were displaced forward in hips extended compared with the standard position, whereas in the lateral decubitus position, the L4/5 and L5/S nerve courses were displaced posteriorly compared with the standard position. The L3/4 and L4/5 nerve roots are located posterior to the vertebral body center. These were found to be offset to the rear when the hip is flexed or the lateral decubitus position is assumed. The present study is the first to elucidate changes in the course of the lumbar nerves as this varies by position. The lateral decubitus position or the position supine with hips flexed may be useful for avoiding nerve damage in a direct lateral transpsoas approach. Preoperative DTI seems to be useful in evaluating the lumbar nerve course as it relates anatomically to the vertebral body.