井上 雅寛

Study design: A multicenter cross-sectional study. Objectives: To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Summary of background data: Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear. Methods: Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score. Results: Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg. Conclusions: Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. Graphical abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].

BACKGROUND: Giant cell tumor is known to be a benign neoplasm that arises most commonly in the long bones, while cases in the spine are rare. Recently, denosumab, a monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand, has been used to treat patients with giant cell tumor. However, there are few reports of total en bloc spondylectomy being used for paravertebral giant cell tumor lesions following denosumab therapy. CASE PRESENTATION: Our patient was a 20-year-old Japanese woman with a 4-month history of lower back pain. A spinal computed tomography scan and magnetic resonance imaging of her lumbar spine revealed an osteolytic lesion involving the L3 vertebral body, and the tumor extended toward the left side of the paravertebral soft tissue and into the left pedicle. The lesion was diagnosed as a giant cell tumor by needle biopsy. Denosumab treatment calcified the paravertebral giant cell tumor lesion and the tumor vertebral body was removed completely by total en bloc spondylectomy. CONCLUSION: This case report describes a patient with a paravertebral giant cell tumor who was successfully treated by preoperative denosumab injection followed by total en bloc spondylectomy.

STUDY DESIGN: A basic study using a rodent model of sarcopenia. OBJECTIVE: To elucidate the contribution of oxidative stress to muscle degeneration and the efficacy of antioxidant treatment for sarcopenia using an animal model of neurogenic sarcopenia. SUMMARY OF BACKGROUND DATA: Oxidative stress has been reported to be involved in a number of pathologies, including musculoskeletal disorders. Its relationship with sarcopenia, one of the potential origins of lower back pain, however, is not yet fully understood. METHODS: Myoblast cell lines (C2C12) were treated with H2O2, an oxidative stress inducer, and N-acetyl-L-cysteine (NAC), an antioxidant. Apoptotic effects induced by oxidative stress and the antioxidant effects of NAC were assessed by western blotting, immunocytochemistry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assays. An animal model of sarcopenia was produced via axotomy of the sciatic nerves to induce muscle atrophy. Twenty-four male Sprague-Dawley rats were divided into sham, sham+NAC, axotomy, and axotomy+NAC groups. Rats were provided water only or water containing NAC (1 g/L) for 4 weeks. The gastrocnemius muscle was isolated and stained with hematoxylin and eosin (H&E) 2 weeks after axotomy, from which muscle cells were harvested and protein extracted for evaluation. RESULTS: Mitogen-activated protein kinases (MAPKs) were significantly activated by H2O2 treatment in C2C12 cells, which was ameliorated by NAC pretreatment. Furthermore, H2O2 induced apoptosis and death of C2C12 cells, which was prevented by NAC pretreatment. The weight of the gastrocnemius muscle was reduced in the axotomy group, which was prevented by NAC administration. Lastly, although muscle specimens from the axotomy group showed greater reductions in muscle fiber, the oral administration of NAC significantly inhibited amyotrophy via antioxidant effects. CONCLUSION: The current in vitro and in vivo study demonstrated the possible involvement of oxidative stress in sarcopenic pathology. NAC represents a potential anti-sarcopenic drug candidate, preventing amyotrophy and fatty degeneration. LEVEL OF EVIDENCE: 4.

BackgroundUnilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis (LSS) is a less invasive technique compared to conventional laminectomy. Recently, several authors have reported favorable results of low back pain (LBP) in patients of LSS treated with ULBD. However, the detailed changes and localization of LBP before and after ULBD for LSS remain unclear. Furthermore, unsymmetrical invasion to para-spinal muscle and facet joint may result in the residual unsymmetrical symptoms. To clarify these points, we conducted an observational study and used detailed visual analog scale (VAS) scores to evaluate the characteristics and bilateral changes of LBP and lower extremity symptoms.MethodsWe included 50 patients with LSS treated with ULBD. A detailed visual analogue scale (VAS; 100mm) score of LBP in three different postural positions: motion, standing, and sitting, and bilateral VAS score (approached side versus opposite side) of LBP, lower extremity pain (LEP), and lower extremity numbness (LEN) were measured. Oswestry Disability Index (ODI) was used to quantify the clinical improvement.ResultsDetailed LBP VAS score before surgery was 51.532.5 in motion, 63.0 +/- 30.1 while standing, and 37.8 +/- 31.8 while sitting; and showed LBP while standing was significantly greater than LBP while sitting (p<0.01). After surgery, LBP while standing was significantly improved relative to that while sitting (p<0.05), and levels of LBP in the three postures became almost the same with ODI improvement. Bilateral VAS scores showed significant improvement equally on both sides (p<0.01).Conclusions ULBD improves LBP while standing equally on both sides in patients with LCS. The improvement of LBP by the ULBD surgery suggests radicular LBP improved because of decompression surgery. Furthermore, the symmetric improvement of LBP by the ULBD surgery suggests unsymmetrical invasion of the paraspinal muscles and facet joints is unrelated to residual LBP.

Introduction: Causes of pain due to spinal metastases have been insufficiently investigated. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were the focus of this study. Both are known as proinflammatory cytokines associated with the pathophysiology of pain syndromes1 ). It is well known that cancer cells produce these cytokines, but whether osteoclasts produce them as well remains unclear. We hypothesize that osteoclasts produce these cytokines; in other words, pain from spinal metastasis is stronger than pain from the primary tumor. Methods: We made a rat spinal metastasis model of breast cancer (metastasis group) and models with a hole in the vertebrae (puncture group) and resected the vertebrae. Tartrate-resistant acid phosphatase (TRAP) staining was performed to reconfirm that osteoclasts increase in vertebrae with spinal metastasis. We then evaluated TNF-α and IL-6 expression using immunohistochemistry and real-time polymerase chain reaction (PCR). Results: The results of TRAP staining showed that osteoclasts increase in metastatic vertebrae. The osteoclasts in the puncture models were TNF-α negative but were TNF-α positive in the metastasis model. The osteoclasts in the puncture models and metastasis model were both IL-6 positive. According to the real-time PCR results, TNF-α in vertebrae increased in the metastasis model, but IL-6 did not increase in the metastasis model compared with in the puncture model. Conclusions: The number of osteoclasts is higher in the metastasis model. While TNF in the osteoclasts increased in the spinal metastasis model, IL-6 did not. This probably means that breast cancer affects TNF production in osteoclasts. This increase of TNF-α may lead to pain from spinal metastasis.

The incidence of spinal fusion surgery and associated adjacent segment disease (ASD) is steadily increasing. We report three cases of ASD after posterior fixation, treated by oblique lateral interbody fusion (OLIF). All cases had a good postoperative course. Altogether, OLIF surgery may be a viable option for treating ASD.

Introduction: Limb muscle mass measurement using dual-energy X-ray absorptiometry (DXA) is considered the gold standard for the diagnosis of sarcopenia. Moreover, bioelectrical impedance analysis (BIA) is also recognized as a beneficial tool considering its high correlation with DXA. However, it remains to be elucidated whether DXA and BIA can accurately measure trunk lean mass. The aim of this study was to investigate the correlation between DXA and BIA measurements of trunk muscle mass and the cross-sectional area (CSA) of trunk muscles measured using magnetic resonance imaging (MRI) and to compare measures of trunk muscle mass obtained using DXA and BIA in patients with low back pain (LBP). Methods: In total, 65 patients participated in the study. The correlation between DXA and BIA measurements and the CSA of trunk and paraspinal muscles at the L4-5 level were calculated. In addition, the correlation between DXA and BIA measurements of trunk muscle mass and the differences between these two measurements were determined. Results: The correlation coefficient between DXA and BIA trunk muscle mass measurement and trunk muscle CSA was 0.74 and 0.56 for men and 0.69 and 0.44 for women, respectively. DXA and BIA measurement values showed a significantly moderate correlation with the CSA of the erector spinae (ES) and psoas major (PM). The multifidus (MF) CSA did not correlate with measurements of DXA and BIA in both men and women. Although DXA and BIA measurements were significantly correlated, a significant difference between these two measurements was found. BIA overestimated the trunk muscle mass significantly compared with DXA. Conclusions: Trunk muscle mass measured with DXA and BIA was correlated with the CSA of most trunk muscles. Although the measurement of DXA and BIA showed a high correlation, BIA overestimated trunk muscle mass compared with DXA. Both DXA and BIA are beneficial for measuring trunk muscle mass.

Introduction: Wearable accelerometers can be used to evaluate waking and sleeping movements. Although a correlation between accelerometer data captured at the wrist and waist has been reported, it has not been evaluated in patients with low back pain. Therefore, this study aimed to evaluate correlations between movement measured at the wrist and waist, using wearable accelerometers, in patients with low back pain. Methods: Twenty patients with chronic low back pain and 20 healthy volunteers were enrolled. Two identical accelerometers were simultaneously worn by each participant, one on the nondominant wrist and the other at the waist, for 1 week. We compared the mean number of active movements and mean total amount of movement between the wrist and the waist to evaluate daytime and sleep activities. During sleep, we also evaluated sleep efficiency and time awake after sleep onset. Results: In daytime activity, the mean number of active movements and mean total amount of movement was greater for the wrist than for the waist, and the amount of waist movements relative to wrist movements was significantly lower in patients with low back pain than in healthy volunteers (p < 0.05). Despite these differences, the mean number of active movements and mean total amount of movement at the wrist and waist were strongly correlated in both groups. During sleep, although there was no difference in either measured sleep efficiency at the wrist or waist or time awake after sleep onset, measurements were strongly correlated in both groups. Conclusions: A strong correlation between movement data at the wrist and waist during both daytime activities and sleep was identified in patients with low back pain. Therefore, a wearable accelerometer worn on the wrist can reliably measure the movement of patients with low back pain, simplifying data capture for clinical and research purposes and improving patient comfort.

Introduction: Thus far, few reports have described the time series histological variations in injured paravertebral muscle tissues for long durations, considering the type of pain. The purpose of this study is to evaluate histological changes in injured paravertebral muscles and dominant nerves considering the type of pain. Methods: We used 59 eight-week-old male Sprague-Dawley rats. A 115-g weight was dropped from a height of 1 m on the right paravertebral muscle. Fluoro-Gold (FG), a sensory nerve tracer, was injected into this muscle. Hematoxylin and eosin (HE) staining and nerve growth factor (NGF) immunostaining of the muscle were performed for histological evaluation. L2 dorsal root ganglia (DRG) on both sides were resected, and immunohistochemical staining was performed for calcitonin gene-related peptide (CGRP, a pain-related neuropeptide) and for activating transcription factor 3 (ATF3, a neuron injury marker). Each examination was performed at 3 days, 1-3 weeks, and 6 weeks after injury. Results: HE staining of the paravertebral muscle indicated infiltration of inflammatory cells and the presence of granulation tissue in the injured part on the ipsilateral side at 3 days and 1 week after the injury. Fibroblasts and adipocytes were present at 2-3 weeks. At 6 weeks, the injured tissue was almost completely repaired. NGF was detected at 2-3 weeks post injury and appeared to colocalize with fibroblasts, but was not observed at 6 weeks post injury. The percentage of cells double-labeled with FG and CGRP in FG-positive cells of the primary muscle was significantly higher in the injured side at 3 days and 1-3 weeks post injury (P < 0.05). However, at 6 weeks, no significant difference was observed. No significant expression of ATF3 was observed. Conclusions: These results suggest that sensitization of the dominant nerve in the DRG, in which NGF may play an important role, can protract pain in injured muscles.

STUDY DESIGN: Cross-sectional observational study. PURPOSE: To compare measurements of appendicular skeletal muscle mass (ASMM) and whole fat mass (WFM) obtained using dualenergy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) among patients with low back pain (LBP). Moreover, the study investigated the correlation between BIA-based ASMM and DXA-based bone mineral density (BMD). Overview of the Literature: If reliable, BIA may be a useful alternative to DXA as a screening tool for sarcopenia and osteoporosis among patients with LBP. METHODS: Measurements were performed in 130 patients, including BMD of the lumbar spine and femoral neck. The correlation between DXA and BIA as well as between BIA-ASMM and BMD were evaluated. RESULTS: BIA and DXA were highly correlated in both male and female patients (r =0.73-0.90, p <0.0001). However, BIA consistently overestimated ASMM by 1.5-2.5 kg on an average (p <0.0001) and underestimated WFM (-4.0 to -2.7 kg) on an average (p <0.0001). BIA-based ASMM correlated with BMD of the lumbar spine in both male and female patients (r =0.28-0.37, p ≤0.02) and that of the femoral neck (r =0.34-0.51, p ≤0.005). Regarding the calculated skeletal muscle index (SMI: ASMM/height [m2]) used as a criterion for sarcopenia, BIA-based SMI correlated with BMD of the lumbar spine in male patients (r =0.44, p =0.0004) and that of the femoral neck in female patients (r =0.33, p =0.009). CONCLUSIONS: BIA may be a favorable alternative to DXA as a screening tool for sarcopenia and osteoporosis among patients with LBP. Considering the overestimation of BIA-based ASMM and SMI, we recommend using the cutoff values for sarcopenia of 7.9 kg/m2 for males and 6.1 kg/m2 for females.

STUDY DESIGN: A retrospective study. OBJECTIVE: The aim of this study was to determine the publication rate and impact factors (IFs) among all abstracts presented at the 2010 and 2012 meetings of the International Society for the Study of Lumbar Spine (ISSLS). SUMMARY OF BACKGROUND DATA: The publication rate of abstracts presented at overseas meetings was reported to be around 50%. However, the publication rate and IFs of oral and poster presentations made at ISSLS meetings were unclear. Moreover, whether the publication rates and IFs differed for papers associated with oral or poster presentations at ISSLS meetings was unknown. METHODS: We investigated all 1126 abstracts (oral, special posters, general posters) presented at ISSLS meetings held between 2010 and 2012. PubMed was searched to identify publications and IFs were determined using journal citation reports. We also compared the publication rates and IFs between oral and poster presentations. RESULTS: The overall publication rate was 50.1% for three ISSLS meetings (564 publications/1126 abstracts). The overall publication rate for oral presentations, special posters, and general posters given in the 2010 to 2012 meetings was 62.0%, 48.3, and 46.6%, respectively. Overall, papers related to oral presentations had significantly higher publication rates than those of special and general posters (P = 0.0002). The average IFs of publications associated with abstracts presented at three ISSLS meetings was 2.802 for oral presentations, 2.593 for special posters, and 2.589 for general posters. There were no significant differences in average IFs between oral and poster presentations (P > 0.05). CONCLUSION: The publication rate for abstracts presented at ISSLS meetings was high and similar to publication rates for abstracts presented at other meetings concerning orthopedic and spine research. However, there was no significant difference in IFs between oral and poster presentations, suggesting that abstract evaluations cannot predict IFs of the eventual publication. LEVEL OF EVIDENCE: 4.

type:text [要旨] 【目的】ラット筋損傷モデルを用いて圧迫，冷却療法による治療効果を比較した。 【方法】8 週齢雄性SDラットを用いdrop mass 法にてモデル作成し，損傷後3 時間にゴムで損傷部を30分圧迫した圧迫群（n＝36），氷で損傷部を30分冷却した冷却群（n＝36），未治療群（n＝36）の3 群について比較を行った。損傷後3 ， 6 ，18，24時間， 3 日， 1 週， 2 週の腓腹筋をHE染色で評価した。損傷後3 ，6 ，18，24時間の腓腹筋をELISA法にてTNF-α の定量評価を行った。損傷部にフルオロゴールド(FG）を留置し，損傷後3 日のL4 後根神経節でCGRP（疼痛関連ペプチド）による免疫組織化学染色を行った。 【結果】組織では未治療群と比し，圧迫群は損傷後6 時間以降で出血や浮腫が少ない傾向にあった。冷却群は，損傷後6 時間で出血や浮腫は減少するも，損傷後18時間以降で増強した。損傷後1週で未治療群は筋組織の壊死が残存するも，圧迫群，冷却群は筋線維修復が認められた。サイトカインは，圧迫群は未治療群と比し損傷後3 ， 6 ，18時間共に低値を示した。特に損傷後6 時間で有意に低値であった（P＜0.05）。冷却群は未治療群と比し損傷後3 ，6 時間で一過性な上昇を示すも，損傷後18時間では有意に低下した（P＜0.05）。L4 後根神経節でのFG 陽性細胞中のFG とCGRP で二重標識される細胞の割合は，圧迫群，冷却群ともに未治療群と比し有意に低かった（P＜0.05）。 【考察】圧迫，冷却療法は筋組織修復を促進し，疼痛の遷延化を予防するが，急性期では異なる経時的変化を示し，組織修復過程に差異がある可能性が示唆された。 [SUMMARY] Purpose. To compare compression and ice treatments in a rat model of muscle injury. Methods. A model of muscle injury was made in 108 eight-week-old Sprague Dawley male rats by dropping a weight onto their right gastrocnemius muscle. We compared compression and ice treatments after the contusion injury with no treatment. We evaluated the injuries using histology andan enzyme-linked immunosorbent assay for tumor necrosis factor α. We used Fluoro-Gold to traceneural afferents from the region of the contusion injury. The proportion of calcitonin gene-related peptide-immunoreactive neurons in all Fluoro-Gold-labeled neurons was determined to evaluate pain. Results. In the compression treatment group, the injured muscle tended to have less hemorrhage and edema at ? 6 h after the injury. Tumor necrosis factor α levels were lower, and the local acutephase in flammatory reaction was milder than in untreated rats. We found less necrosis of muscle tissue on the third day after injury and the replacement of granulation tissue and regeneration of muscle fibers 1 week after the injury. The proportion of calcitonin gene-related peptide-immunoreactive Fluoro-Gold-labeled neurons in total Fluoro-Gold-labeled neurons was significantly lower than in untreated rats. In the ice treatment group, although injured muscle had decreased hemorrhage and edema 6 h after the injury, hemorrhage and edema increased ?18 h after injury. Tumor necrosis factor α levels were transiently increased compared with those in untreated rats（ 3 h and 6 h after contusion）. On the third day after contusion injury, necrosis of muscle was severe. We observed the replacement of granulation tissue and regeneration of muscle fibers 1 week after the injury. The proportion of calcitonin gene-related peptide-immunoreactive Fluoro-Gold-labeled neurons was significantly lower than in untreated rats. Conclusion. In our study, compression may promote muscle tissue repair by preventing hematoma formation during the repair phase and preventing prolonged pain. On the other hand, ice therapy may prevent prolonged pain through pain relief from the stimulation of cold receptors, enabling animals to proceed with an early range of motion exercise, suppressing hypoactivity and promoting muscle tissue repair during the recovery phase. Overall, our current study indicated that there was a difference between compression and ice treatments during the acute and repair phases of muscle injury.