Variety of the Wave Change in Compound Muscle Action Potential in an Animal Model

Study DesignAnimal study.PurposeTo review the present warning point criteria of the compound muscle action potential (CMAP) and investigate new criteria for spinal surgery safety using an animal model.Overview of LiteratureLittle is known about correlation palesis and amplitude of spinal cord monitoring.MethodsAfter laminectomy of the tenth thoracic spinal lamina, 2-140 g force was delivered to the spinal cord with a tension gage to create a bilateral contusion injury. The study morphology change of the CMAP wave and locomotor scale were evaluated for one month.ResultsFour different types of wave morphology changes were observed: no change, amplitude decrease only, morphology change only, and amplitude and morphology change. Amplitude and morphology changed simultaneously and significantly as the injury force increased (p<0.05) Locomotor scale in the amplitude and morphology group worsened more than the other groups.ConclusionsAmplitude and morphology change of the CMAP wave exists and could be the key of the alarm point in CMAP

Efficacy of Anal Needle Electrodes for Intraoperative Spinal Cord Monitoring with Transcranial Muscle Action Potentials

Study Design Retrospective study. Purpose To examine the relationship between postoperative bowel bladder disorder (BBD) and the efficacy of needle electrodes for the external anal sphincter (EAS) in intraoperative spinal cord monitoring with transcranial muscle action potentials (Tc-MsEP). Overview of Literature Spinal surgery for spina bifida, spinal cord tumor, and spinal tethered cord syndrome has a high rate of postoperative BBD. Monitoring of the EAS with Tc-MsEP is frequently performed during spinal surgery. We initially used plug-surface electrodes for this purpose, but have more recently switched to needle electrodes for the monitoring of the EAS. To date, there has been no comparison between the utility of these electrodes. Methods Waveform derivation, exacerbation of postoperative BBD, and sensitivity and specificity for prediction of BBD by 70% amplitude reduction of EAS activity using needle and plug-surface electrodes were investigated in 239 spine surgeries. The cut-off for the % drop in amplitude for BBD prediction was determined for EAS monitoring using a needle electrode. Results The overall rate of postoperative BBD aggravation was 7.1% (17/239 cases), with the individual rates using needle and plug-surface electrodes being 6.9% (8/116) and 7.3% (9/123), respectively. The waveform derivation rate was significantly higher using needle electrodes (91.3% [106/116] vs. 76.4% [94/123], p <0.01). In patients with baseline waveform detection, the sensitivity and specificity for postoperative BBD were similar in the two groups. With needle electrodes, a cutoff amplitude of Tc-MsEP for the EAS at the end of surgery of 25% of the baseline amplitude had a sensitivity of 89% and specificity of 82% for the prediction of postoperative BBD aggravation. Conclusions The significantly higher waveform derivation rate using needle electrodes suggests that these electrodes are effective for monitoring the EAS in spinal surgery in cases with preoperative BBD

Minimization of lumbar interbody fusion by percutaneous full-endoscopic lumbar interbody fusion (PELIF), and its minimally invasiveness comparison with minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF)

Objective: In fusion surgery, minimization of muscle damage and bone resection is important. To achieve these, we have developed a percutaneous full endoscopic lumbar interbody fusion (PELIF). We report the detailed operation procedure, and moreover a comparison of its minimally invasiveness with that of the minimally invasive surgery-transforminal lumbar interbody fusion (MIS-TLIF). Methods: 52 patients were treated with PELIF. Total discectomy and cartilage endplate removal were performed using an 8 mm rotate-cutter. A cage was sandwiched between two L-retract sliders, which protected the exiting root. The cancellous bone chips were harvested from the pelvis with a 5 mm trephine.On the other hand, 74 patients were treated with MIS-TLIF. Results: In PELIF, bleeding volume, VAS (back pain), ODI, JOA score, and Macnab’s criteria were significantly superior to MIS-TLIF except for VAS (leg symptom).The MRI cross-sectional area of degenerative spondylolisthesis was significantly improved after PELIF, but that of MIS-TLIF was significantly broader.PELIF was superior to MIS-TLIF in fat degeneration of multifidus muscle in the cross-sectional MRI under 50 years old.CT recognized insufficient fusion in one case of PELIF and seven cases of MIS-TLIF, with a tendancy to have more insufficient fusion in MIS-TLIF. Conclusions: PELIF provides clear visualization under continuous water irrigation. PELIF is an indirect decompression without canal invasion. The dura mater, intestine, and large blood vessels don’t appear in the surgical field. It is understood that PELIF is a less invasive surgery than MIS-TLIF

Low Back Pain in Patients with Lumbar Spinal Stenosis―Hemodynamic and electrophysiological study of the lumbar multifidus muscles

Introduction: Several studies have demonstrated improvement in low back pain (LBP) after decompression surgery for lower extremity symptoms in lumbar spinal stenosis (LSS); however, the influence of neuropathic disorders on LBP is uncertain. Aim of this study is to identify the features of motion-induced and walking-induced LBP in patients with LSS and to assess whether neuropathic LBP develops. Methods: In total, 234 patients with LSS including L4/5 lesion were asked to identify their LBP. Subjects were classified into three groups: walking-induced LBP that aggravated during walking (W group), motion-induced LBP that aggravated during sitting up (M group), and no LBP (N group). Cross-sectional areas of the dural sac, lumbar multifidus, and the erector spinae were measured. Intramuscular oxygenation was evaluated with near-infrared spectrophotometer. Surface electromyography (EMG) and mechanomyography (MMG) were performed on the lumbar multifidus. Morphological, hemodynamic, and electrophysiological differences in the onset of LBP were evaluated. Results: The prevalence of W, M, and control groups was 31.2%, 32.1%, 36.8%, respectively. Concordance between the laterality of LBP and leg symptoms including pain and numbness was 86.3% in the W group and 47.0% in the M group. Dural sac area was lower in the W group than in the M and control groups. In the hemodynamic evaluation, the oxygenated hemoglobin level was significantly lower in the W group than in the M and N groups. In electrophysiological evaluation of lumbar multifidus, the mean power frequency in EMG was significantly higher in the W group than in the N group. Amplitude in MMG was significantly lower in the W group than in the N group. Conclusions: Neurologic disturbance in patients with LSS may be attributed to “neuropathic LBP.” Neuropathic multifidus disorder plays a role in walking-induced LBP

Sarcopenia in elderly patients with chronic low back pain

Objectives: The prevalence of chronic low back pain (CLBP) increases with age and several mechanisms are involved in the development of CLBP, including osteoporosis; however, no associations with sarcopenia have yet been identified. Methods: In total, 100 patients with CLBP and 560 patients without CLBP (nCLBP) aged over 65 years were studied. Skeletal muscle mass index (SMI) and percentage of body fat were evaluated using whole-body dual-energy X-ray absorptiometry. Sarcopenia was diagnosed when the relative SMI was more than 2 standard deviations below the mean in young adults. Thus, the cutoff value for sarcopenia was defined according to Sanada's Japanese population data. Paraspinal muscle cross-sectional areas of the lumbar multifidus and the erector spinae muscles were calculated using magnetic resonance imaging. Results: Forty patients (40.0%) from the CLBP group and 149 (26.6%) from the nCLBP group met the criteria of sarcopenia. SMI was significantly lower and the body fat ratio was significantly higher in the CLBP group compared with the nCLBP group. Sarcopenic obesity was significantly observed in the CLBP group. Lumbar multifidus and the erector spinae muscle cross sectional area were significantly lower in the CLBP group. Conclusions: Elderly patients with CLBP have significantly lower skeletal muscle mass, and age-related mechanisms in sarcopenia are considered to be associated with chronic pain. Therapeutic procedures that are used to treat elderly aging muscle, including muscle strengthening and performance training, can possibly be a treatment for or used to prevent elderly CLBP

Corrective surgery for kyphosis in a case of Gaucher's disease without history of vertebral compression fractures

Introduction: Gaucher's disease is a congenital metabolic disorder characterized by the accumulation of glucocerebroside in the reticuloendothelial system. Its clinical manifestations include splenomegaly, osteopenia, and pathological fractures. Cases of patients with kyphotic deformities caused by pathological vertebral compression fractures associated with Gaucher's disease are well reported. However, there has been no report regarding surgical treatment of kyphotic deformity caused by Gaucher's disease without compression fractures. In the present report, we describe surgical treatment for kyphotic deformity caused by Gaucher's disease without a past history of vertebral compression fractures. Case Report: The patient was diagnosed with Gaucher's disease at the age of 15 months. The patient was a 10-year-old girl with progressive kyphosis (84° between T6 and L3, with T12 as the apical vertebra) without compression fractures. Although the patient had been treated using a brace since the age of 3 years, the kyphosis progressed to the point where corrective surgery was required. We initially performed T3-L3 posterior spinal fusion, followed by anterior fusion 3 months later, which corrected the kyphosis to 35°. Postoperatively, the patient suffered fractures of the upper and lower extremities but did not have spinal fractures. Conclusions: Two-stage anterior/posterior combined correction and fusion was performed in a patient with kyphotic deformity caused by Gaucher's disease without compression fractures. Because of bone fragility in Gaucher's disease, careful selection of the fusion range and postoperative therapy was necessary

Sarcopenia affects conservative treatment of osteoporotic vertebral fracture

Objectives: Sarcopenia and osteoporosis affects activities of daily living and quality of elderly people. However, little is known about its impact on elderly locomotor diseases, such as osteoporotic vertebral fracture (OVF). There is no report investigating the influence of both sarcopenia and osteoporosis on outcomes of OVF. This study aimed to evaluate the clinical outcomes of OVF in elderly patients from sarcopenic perspectives. Methods: This prospective study was conducted with 396 patients, aged 65 years or more, hospitalized for the treatment of OVF (mean age, 81.9 ± 7.1 years; 111 males, 285 females). The primary outcome was the Japanese Orthopaedic Association (JOA) score for lumbar disease (at first visit, hospital discharge, and 1 year after treatment) and Barthel index (at the same time and before hospitalization). The second outcome was living place after discharge. Susceptibility to sarcopenia and osteoporosis were evaluated and clinical results of conservative treatment were compared. Results: Sarcopenia significantly affected Barthel index at first visit and discharge. Sarcopenia patients had significantly higher rate for discharge to nursing home and living in nursing home after 1 year than patients without sarcopenia. Osteoporosis significantly affected the JOA score at the first visit and the Barthel index before hospitalization, at the first visit, discharge, and after 1 year. Osteoporosis did not affect the living place at discharge and after 1 year. Conclusions: Sarcopenia and osteoporosis affected outcomes of conservative treatment for OVF; moreover, sarcopenia affected the living place of OVF patients at discharge and after 1 year. Keywords: Sarcopenia, Vertebral fracture, Conservative treatmen