Three-dimensional analysis of the characteristics of joint motion and gait pattern in a rodent model following spinal nerve ligation.

BACKGROUND: The spinal nerve ligation (SNL) rat is well known as the most common rodent model of neuropathic pain without motor deficit. Researchers have performed analyses using only the von Frey and thermal withdrawal tests to evaluate pain intensity in the rat experimental model. However, these test are completely different from the neurological examinations performed clinically. We think that several behavioral reactions must be observed following SNL because the patients with neuropathic pain usually have impaired coordination of the motions of the right-left limbs and right-left joint motion differences. In this study, we attempted to clarify the pain behavioral reactions in SNL rat model as in patients. We used the Kinema-Tracer system for 3D kinematics gait analysis to identify new characteristic parameters of each joint movement and gait pattern. RESULTS: The effect of SNL on mechanical allodynia was a 47 ± 6.1% decrease in the withdrawal threshold during 1-8 weeks post-operation. Sagittal trajectories of the hip, knee and ankle markers in SNL rats showed a large sagittal fluctuation of each joint while walking. Top minus bottom height of the left hip and knee that represents instability during walking was significantly larger in the SNL than sham rats. Both-foot contact time, which is one of the gait characteristics, was significantly longer in the SNL versus sham rats: 1.9 ± 0.15 s vs. 1.03 ± 0.15 s at 4 weeks post-operation (p = 0.003). We also examined the circular phase time to evaluate coordination of the right and left hind-limbs. The ratio of the right/left circular time was 1.0 ± 0.08 in the sham rats and 0.62 ± 0.15 in the SNL rats at 4 weeks post-operation. CONCLUSIONS: We revealed new quantitative parameters in an SNL rat model that are directly relevant to the neurological symptoms in patients with neuropathic pain, in whom the von Frey and thermal withdrawal tests are not used at all clinically. This new 3D analysis system can contribute to the analysis of pain intensity of SNL rats in detail similar to human patients' reactions following neuropathic pain.

A systematic review and meta-analysis comparing anterior decompression with fusion and posterior laminoplasty for cervical spondylotic myelopathy.

BACKGROUND: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial because there are few comprehensive studies that have investigated the surgical methods. Therefore, we conducted a systematic review and meta-analysis to evaluate evidence in the literature and to compare the surgical outcomes between anterior decompression with fusion (ADF) and laminoplasty, which are representative procedures for CSM. METHODS: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and laminoplasty for CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies of CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and treatments with posterior instrumented fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, cervical alignment, surgical complications and reoperation rates. Then, a meta-analysis was performed on these surgical outcomes. RESULTS: Nine studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the preoperative JOA score was similar between the ADF and laminoplasty groups. The postoperative JOA scores and neurological recovery rates were not different between the ADF and laminoplasty groups. ADF exhibited more favorable results than laminoplasty in terms of postoperative cervical alignment. In contrast, overall complications were more frequently observed in the ADF group than in the laminoplasty group, leading to higher rates of reoperation. However, postoperative neck pain was more frequently observed in the laminoplasty group than in the ADF group. CONCLUSIONS: This systematic review and meta-analysis showed both the merits and shortcomings of ADF and laminoplasty. ADF and laminoplasty showed similar results in terms of neurological recovery. Postoperative cervical lordosis was better preserved with ADF than with laminoplasty. However, ADF was associated with a higher incidence of surgical complications than laminoplasty.

Impact of background factors on outcomes of pharmacological therapy for chronic low back pain: A nationwide multicenter prospective study.

BACKGROUND: Chronic low back pain (CLBP) is a major cause of chronic pain with nociceptive, neuropathic or both pain components, and a leading cause of disability. The objectives of this study were to determine the impact of background factors including previous use of drugs on outcomes of pharmacological therapy for CLBP in a nationwide multicenter prospective study. METHODS: The subjects were 474 patients (male: 41.9%, median age: 73.0) with CLBP. Background factors that could influence outcomes after pharmacological treatment for 6 months were examined: age, gender, body mass index (BMI), duration of CLBP, osteoporosis, history of spinal surgery, history of malignant tumor, smoking habit, employment status (yes or no), exercise habit (frequency), number of live-in family members, having something to do for pleasure, Center for Epidemiologic Studies depression scale (CES-D) score, and medication at baseline. Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) for LBP, JOA Back Pain Evaluation Questionnaire (JOABPEQ), Roland-Morris Disability Questionnaire (RDQ), Short-form 8-item health survey (SF-8), and EQ-5D were used for evaluation at baseline and after 6 months. Multivariate linear regression models were used in statistical analysis. RESULTS: Drugs for neuropathic pain at baseline (p < 0.001), Tramacet® at baseline (p < 0.05), weak opioids at baseline (p < 0.05), older age (p < 0.001), long disease duration (p < 0.005), history of spinal surgery (p < 0.001), and smoking habit (p < 0.001) had significant negative effects on outcomes. Employment (p < 0.05), exercise habit (p < 0.05), and CED-D at baseline (p < 0.001) had positive effects on outcomes. CONCLUSIONS: This is the first study to identify significant prognostic factors for outcomes of pharmacological treatment of CLBP. The neuropathic pain component of CLBP at baseline is a major significant negative factor for most outcomes involving improved pain, activities of daily life, and quality of life. Treatment strategies developed with consideration of these factors may be advantageous for recovery from CLBP.

Comparison of anterior decompression with fusion and posterior decompression with fusion for cervical spondylotic myelopathy-A systematic review and meta-analysis.

BACKGROUND: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial. Recently, laminectomy/laminoplasty with instrumented fusion (LAMF) has been increasingly applied to treat CSM. However, few comprehensive studies have compared anterior decompression with fusion (ADF) and LAMF. Therefore, we conducted a meta-analysis to evaluate the evidence in the literature and to compare the surgical outcomes between the 2 procedures. Since the surgical outcomes and risks differ between patients with CSM and ossification of the posterior longitudinal ligament (OPLL) and between only posterior decompression and decompression with fusion treatments, we excluded patients with OPLL and patients with only posterior decompression in this review. METHODS: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and LAMF for the treatment of CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies about CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and with the treatment of posterior decompression without fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI) scores, cervical alignment data, and surgical complications. Then, a meta-analysis was performed on these surgical outcomes. RESULTS: Eleven studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the pre- and postoperative JOA scores were similar between the ADF and LAMF groups. The ADF group exhibited more favorable results than the LAMF group in terms of postoperative cervical alignment and the NDI. Overall complications were similar between the ADF and LAMF groups; however, C5 palsy was more frequently observed in the LAMF group than in the ADF group. CONCLUSIONS: While the ADF and LAMF groups demonstrated similar results in terms of neurological recovery, postoperative cervical lordosis and NDI scores were more favorable with ADF than with LAMF. The overall complication rate was similar between the ADF and LAMF groups. Surgeons should understand the merits and shortcomings of both procedures when deciding on a surgical procedure.

Early diagnosis of septic arthritis using synovial fluid presepsin: A preliminary study.

Therapeutic outcomes for septic arthritis vary greatly depending on the span of time between disease-onset and surgery. The most important factor is making an early and definitive diagnosis; however, some cases may be difficult to diagnose. We investigated presepsin, a biomarker of sepsis, to determine whether or not presepsin in synovial fluid would be useful for the diagnosis of septic arthritis. We selected 18 patients with septic arthritis including periprosthetic joint infections (SA group) and 28 patients with osteoarthritis (OA group). We measured the concentrations of synovial fluid presepsin, blood presepsin and procalcitonin (PCT) in the two groups. We compared the sensitivities and specificities of synovial fluid presepsin, blood presepsin and PCT. Synovial fluid and blood presepsin and blood PCT were all significantly higher in the SA group. Synovial fluid presepsin exhibited both 100% sensitivity and 100% specificity in the SA group, which were higher rates than those for blood presepsin and PCT. We found that synovial fluid presepsin is markedly elevated in case of septic arthritis, and therefore, it has potential as a new biomarker of septic arthritis.

Multicenter cross-sectional study of the clinical features and types of treatment of spinal cord-related pain syndrome.

BACKGROUND: We termed chronic neuropathic pain (NeP) in patients with diseases associated with spinal cord damage as "spinal cord-related pain syndrome". We conducted a survey of patients with the syndrome to assess the type and severity of NeP and its effect on QOL, and treatment modalities. METHODS: This cross-sectional study was conducted in 185 patients recruited from 15 medical institutions. We analyzed the questionnaires sent to clinicians (basic information, magnetic resonance imaging (MRI) findings, type and effectiveness of medications) and patients [modified Neuropathic Pain Symptom Inventory (NPSI) and short form (SF)-36 healthy survey]. RESULTS: The incidence of spinal cord-related pain syndrome was highest in patients with cervical spondylotic myelopathy, ossification of posterior longitudinal ligament (OPLL) and spinal cord injury. The number of patients with at-level pain was higher than those with below-level pain; dysesthesia/paresthesia, spontaneous and evoked pain types were mainly seen in patients with at-level pain and dysesthesia/paresthesia was common among those with below-level pain. NPSI score was higher than 10 in the majority of patients, and the subscore for dysesthesia/paresthesia was significantly the highest. The NPSI score was the highest in patients with severe hyperintense signal increase on MRI. The scores of all SF-36 sub-items were significantly lower than the national average. The majority of patients used non-steroid anti-inflammatory drugs and gabapentin/pregabalin; the latter was significantly effective for allodynia, compared with other medications, regardless of the pain level. CONCLUSIONS: The majority of patients with spinal cord-related pain syndrome suffered from severe NeP, which affected physical activity. The pain phenotype varied according to the level of the lesion and dysesthesia/paresthesia was the most intense. Compared with other medications, gabapentin/pregabalin was significantly effective especially for dysesthesia/paresthesia and evoked pain regardless of the pain level.

Cost-effectiveness analysis of the pharmacological management of chronic low back pain with four leading drugs.

BACKGROUND: Chronic low back pain is a major health problem that has a substantial effect on people's quality of life and places a significant economic burden on healthcare systems. However, there has been little cost-effectiveness analysis of the treatments for it. Therefore, the purpose of this prospective observational study was to evaluate the cost-effectiveness of the pharmacological management of chronic low back pain. METHODS: A total of 474 patients received pharmacological management for chronic low back pain using four leading drugs for 6 months at 28 institutions in Japan. Outcome measures, including EQ-5D, the Japanese Orthopaedic Association (JOA) score, the JOA back pain evaluation questionnaire (BPEQ), the Roland-Morris Disability Questionnaire, the Medical Outcomes Study SF-8, and the visual analog scale, were investigated at baseline and every one month thereafter. The incremental cost-utility ratio (ICUR) was calculated as drug cost over the quality-adjusted life years. An economic estimation was performed from the perspective of a public healthcare payer in Japan. Stratified analysis based on patient characteristics was also performed to explore the characteristics that affect cost-effectiveness. RESULTS: The ICUR of pharmacological management for chronic low back pain was JPY 453,756. Stratified analysis based on patient characteristics suggested that the pharmacological treatments for patients with a history of spine surgery or cancer, low frequency of exercise, long disease period, low scores in lumbar spine dysfunction and gait disturbance of the JOA BPEQ, and low JOA score at baseline were not cost-effective. CONCLUSIONS: Pharmacological management for chronic low back pain is cost-effective from the reference willingness to pay. Further optimization based on patient characteristics is expected to contribute to the sustainable development of a universal insurance system in Japan.

Complications of spinal surgery for elderly patients with lumbar spinal stenosis in a super-aging country: An analysis of 8033 patients.

BACKGROUND: The Japanese Society for Spine Surgery and Related Research (JSSR) performed a third study on complications in spinal surgery in 2011. The purpose was to present information about surgery and complications in a large amount of elderly patients aged 65 years with lumbar spinal stenosis (LSS) without coexisting spondylolisthesis, spondylolysis, or scoliosis, and to compare patients aged ≥80 years to those aged 65-79 years. METHODS: A recordable optical disc for data storage was sent by JSSR in January 2012 to 1105 surgeons certified by the JSSR in order to collect surgical data. Data were returned by the end of May 2012. RESULTS: Data were accumulated for 8033 patients aged 65 years. The incidence of surgical complications was 10.8%, and did not differ significantly between age groups. The incidence of general complications was 2.7%, and differed significantly between age groups (p < 0.005). The highest incidence of surgical complications was for dural tear (DT) (3.6%), followed by deep wound infection (DWI) (1.4%), neurological complications (1.3%), and epidural hematoma (1.3%). Spinal instrumentation was applied in 30.3%. Incidences of surgical complications in instrumented and noninstrumented surgery were 17.3% and 8.8%. In instrumented surgery, incidences of surgical and general complications were higher in the ≥80 year age group than in the 65-79 year age group. Logistic regression analyses showed patients with microendoscopic surgery at increased risk of DT. Patients with diabetes mellitus and instrumented surgery showed increased risks of DWI. CONCLUSIONS: Incidences of surgical complications did not differ significantly between age groups. Attention should be paid to both surgical and general complications, particularly for postoperative mental disease in instrumented surgery for patients≥80 years old.

The efficacy of neuromuscular electrical stimulation with alternating currents in the kilohertz frequency to stimulate gait rhythm in rats following spinal cord injury.

BACKGROUND: Rehabilitation facilitates the reorganization of residual/regenerated neural pathways and is key in improving motor function following spinal cord injury. Neuromuscular electrical stimulation (NMES) has been reported as being clinically effective. Although it can be used after the acute phase post-injury, the optimal stimulation conditions to improve motor function remain unclear. In this paper, we examined the effectiveness of NMES with alternating currents in the kilohertz (kHz) frequency in gait rhythm stimulation therapy. METHODS: Tests were performed using 20 mature female Fischer rats. Incomplete spinal cord injuries (T9 level) were made with an IH impactor using a force of 150 kdyn, and NMES was administered for 3 days from the 7th day post-injury. The needle electrodes were inserted percutaneously near the motor point of each muscle in conscious rats, and each muscle on the left and right leg was stimulated for 15 min at two frequencies, 75 Hz and 8 kHz, to induce a gait rhythm. Motor function was evaluated using Basso, Beattie, Bresnahan (BBB) scores and three-dimensional (3D) gait analysis. Rats were divided into four groups (5 rats/group), including the NMES treatment 75-Hz group (iSCI-NMES 75 Hz), 8-kHz group (iSCI-NMES 8 kHz), injury control group (iSCI-NT), and normal group (Normal-CT), and were compared. RESULTS: There was no significant difference in BBB scores among the three groups. In 3D gait analysis, compared with the injury control group, the 8-kHz group showed a significant improvement in synergistic movement of both hindlimbs. CONCLUSION: We suggest that kHz stimulation is effective in gait rhythm stimulation using NMES.

Cervical ossification of the posterior longitudinal ligament: Biomechanical analysis of the influence of static and dynamic factors.

OBJECTIVE: Cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) is induced by static factors, dynamic factors, or a combination of both. We used a three-dimensional finite element method (3D-FEM) to analyze the stress distributions in the cervical spinal cord under static compression, dynamic compression, or a combination of both in the context of OPLL. METHODS: Experimental conditions were established for the 3D-FEM spinal cord, lamina, and hill-shaped OPLL. To simulate static compression of the spinal cord, anterior compression at 10, 20, and 30% of the anterior-posterior diameter of the spinal cord was applied by the OPLL. To simulate dynamic compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction. To simulate combined static and dynamic compression under 10 and 20% anterior static compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction. RESULTS: The stress distribution in the spinal cord increased following static and dynamic compression by cervical OPLL. However, the stress distribution did not increase throughout the entire spinal cord. For combined static and dynamic compression, the stress distribution increased as the static compression increased, even for a mild range of motion (ROM). CONCLUSION: Symptoms may appear under static or dynamic compression only. However, under static compression, the stress distribution increases with the ROM of the responsible level and this makes it very likely that symptoms will worsen. We conclude that cervical OPLL myelopathy is induced by static factors, dynamic factors, and a combination of both.

The societal burden of chronic pain in Japan: an internet survey.

OBJECTIVES: Chronic pain affects between 10-20 % of the population of Japan and several specific types of chronic pain have been found to be associated with worse health outcomes. The aim of the current study was to investigate the economic burden of chronic pain as well as the health status among Japanese patients. METHODS: Data from the Japan National Health and Wellness Survey (NHWS), a cross-sectional health survey of adults, were used (N = 30,000). Respondents with chronic pain (N = 785) were compared with respondents without chronic pain (N = 29,215) with respect to health status (using the SF-12v2), work productivity and activity impairment (WPAI questionnaire), and healthcare resource use using regression modeling, controlling for demographic and health history covariates. Indirect costs were calculated using wage rates and the human capital method. RESULTS: Back pain (72.10 %) and shoulder pain/stiffness (54.90 %) were the most prevalent pain types. Adjusting for demographic and health history differences, respondents with chronic pain reported lower health status [mental component summary (MCS): 44.26 vs. 51.14; physical component summary (PCS): 44.23 vs. 47.48; both p < 0.05], greater absenteeism (4.74 vs. 2.74 %), presenteeism (30.19 vs. 15.19 %), overall work impairment (31.70 vs. 16.82 %), indirect costs (¥ 1488,385 vs. ¥ 804,634), activity impairment (33.45 vs. 17.25 %), physician visits (9.31 vs. 4.08), emergency room (ER) visits (0.19 vs. 0.08), and hospitalizations (0.71 vs. 0.34) (all p < 0.05). Nearly 60 % of respondents with chronic pain were untreated. The mean level of pain severity in the last week was 5.26 (using a 0-11 scale); being female, being elderly, having low income, and having multiple pain types were significantly associated with greater pain severity (all p < 0.05). Regular exercise was associated with lower pain severity (p < 0.05). CONCLUSIONS: The results suggest that chronic pain has a significant association in an individual's health status, work productivity, daily activity impairment, healthcare resource use, and economic burden in Japan. Along with low treatment rates, a multidisciplinary approach may lead to an improved quality of life and reduce the economic burden among patients with chronic pain in Japan.

Japanese 2011 nationwide survey on complications from spine surgery.

BACKGROUND: The Japanese Society for Spine Surgery and Related Research (JSSR) previously carried out two nationwide surveys in 1994 and 2001 on complications from spine and spinal cord surgery. More than 10 years have now elapsed since 2001. Rapidly ageing populations have major impacts on society, particularly in the medical field. The purpose of this study was therefore to examine the present situation for spine surgery in Japan. METHODS: The JSSR research team prepared a computerized questionnaire made up of two categories in order to capture clinicopathological information and surgical information. A recordable optical disc for data storage was sent to surgeons who were certified for spine surgery by JSSR. The data was analyzed. RESULTS: The JSSR carried out a nationwide survey of complications of 31,380 patients. Patients aged 60 years or older comprised 63.1 % of the overall cohort. This was considerably higher than observed in previous surveys. Degenerative spinal diseases increased 79.7 %. With regard to surgical approach, the incidence of anterior surgery has decreased, while that of posterior surgery has increased compared to the earlier surveys (both p < 0.05). Spinal instrumentation was applied in 30.2 % cases, compared to 27.0 and 34.0 % cases in the 1994 and 2001 surveys, respectively. Intraoperative and postoperative complications were reported in 10.4 % and were slightly increased compared to 8.6 % in the earlier surveys (both p < 0.05). Diseases associated with a high incidence of complication included intramedullary tumor (29.3 %) and primary malignant tumor (22.0 %). The highest incidence of complication was dural tear (2.1 %), followed by neurological complication (1.4 %).

Artificial collagen-filament scaffold promotes axon regeneration and long tract reconstruction in a rat model of spinal cord transection.

Traumatically injured spinal cord (SC) displays structural damage that includes discontinuity of long tracts and cavitations. Axonal regrowth beyond the lesion is necessary to achieve functional recovery following SC injury. We report here the development of an artificial collagen-filament (CF) scaffold to replace the SC in 8-week-old female Fisher rats. Axonal sprouting and regrowth was very rapid following grafting of the CF. One week after implantation, the scaffold was filled with cells of host origin and with regenerated axons. Histological examination of SC adjacent to the scaffold showed little cavity formation or fibrous scarring. Eight weeks after implantation, myelinated nerve fibers were found in the scaffold and 10-25 % of rubrospinal tracts were repaired. Four to six weeks after transplantation, motor evoked potentials were recorded in CF-grafted rats but were not detectable in non-grafted rats. Electrophysiological and histological examinations revealed the grafted CF was likely to function as a nerve tract. In addition, these results suggest that collagen fibers may provide a permissive microenvironment for the elongation of SC axons and to support the process of spinal cord regeneration.

Distal Femoral Cortical Irregularity in children.

Cortical abnormalities at the distal postero-medial femoral metaphysis may be relatively common. We reviewed the plain radiographs of 197 knees in 130 children aged between 5 and 12 years to investigate the incidence of distal femoral cortical irregularities (DFCI) and their association with symptoms. An adductor magnus lesion was found in 15% of cases, with an even number of irregular and cystic lesions. A medial gastrocnemius lesion was found in 5% of cases, but no association was found between symptoms and the lesion. Overall, lesions were found in 25% of cases aged 5 to 9 years, but in only 13% of cases aged 12 and 13 years. Boys showed a higher incidence of both adductor magnus and medial gastrocnemius lesions. DFCI is a benign, self-limited entity and a relatively common radiologic finding. Regardless of whether or not symptoms are present, imaging findings should be carefully interpreted to avoid unnecessary diagnostic and invasive therapeutic procedures.

Usefulness of an early MRI-based classification system for predicting vertebral collapse and pseudoarthrosis after osteoporotic vertebral fractures.

STUDY DESIGN: Retrospective review. OBJECTIVE: To clarify whether an early magnetic resonance imaging-based classification predicts pseudoarthrosis and final vertebral collapse in osteoporotic vertebral fractures. SUMMARY OF BACKGROUND: Initial therapy for osteoporotic vertebral fractures involves bed rest, orthotic use, and plaster casts. However, in some cases, pain persists because of progressive vertebral collapse or pseudoarthrosis. Prediction of these complications immediately after fractures can facilitate early proactive treatment despite the early prognosis being generally poor. METHODS: A total of 109 patients (129 fractured vertebrae, 88 females, 21 males, and average age 79 y) followed up over 6 months after conservative treatment for thoracolumbar vertebral fractures were included. Early midsagittal T1-weighted and T2-weighted magnetic resonance images were analyzed. The incidence of final vertebral body collapse, pseudoarthrosis conversion, and delayed spinal cord paralysis were examined retrospectively for each vertebral fracture type. RESULTS: According to the T1-weighted image-based classification, 74 of the vertebrae (57%) had total-type fractures. The final vertebral body collapse rate was significantly higher in this type than in others. Pseudoarthrosis was observed in 20 total-type fractures in 20 patients (18.3%); pseudoarthrosis conversion rate was significantly higher in these patients than in others. Delayed spinal cord paralysis occurred in only 1 patient (0.9%) with total-type fracture. According to the T2-weighted image-based classification, 69 vertebrae had the hyperintense wide-type fractures, which was the most common fracture type (53%). Hypointense wide-type fractures were associated with a significantly higher incidence of final vertebral body collapse, pseudoarthrosis, and delayed spinal cord paralysis. When total-type fractures of the T1-weighted image-based classification were subclassified according to the T2-weighted image-based classification, a significantly higher pseudoarthrosis conversion rate was observed in hypointense wide-type fractures. CONCLUSIONS: Our results suggest that the radiologic prognosis can be estimated to a limited extent by determining the degree and extent of osteoporotic vertebral fractures using an early magnetic resonance imaging-based classification.

Percutaneous radiofrequency facet joint denervation with monitoring of compound muscle action potential of the multifidus muscle group for treating chronic low back pain: a preliminary report.

STUDY DESIGN: A retrospective review. OBJECTIVE: The aim of this study was to study the effectiveness of percutaneous radiofrequency neurotomy of facet joints by monitoring compound muscle action potentials (CMAPs) of the multifidus muscle group as an objective index of treatment efficacy. SUMMARY OF BACKGROUND: Percutaneous radiofrequency neurotomy of the medial branches of the dorsal rami of the lumbar nerves is a widely accepted treatment for chronic lumbar intervertebral joint pain. However, its success rate has varied in different studies because an objective method for evaluating the facet joint denervation is lacking. METHODS: Fifty-five patients (age range, 19-76 y; mean age, 55 y) with low back pain persisting for ≥3 months, in whom facet block and/or block of the medial branch of the dorsal ramus were only temporarily effective, were included. The Japanese Orthopaedic Association (JOA) scoring system for back pain was used for clinical assessment. JOA scores were measured before treatment and 1 week, 3 months, 6 months, and 12 months afterward. The improvement rate was calculated with ≥40% improvement rate defined as successful, and the success rate was subsequently evaluated. RESULTS: The patient success rate was 75% (41/55) at 1 week, 71% (39/55) at 3 months, 60% (33/55) at 6 months, and 51% (28/55) at 12 months after treatment. Two cases had minor postoperative complications, which were localized burning pain lasting <1 week at the site of electrode insertion. CONCLUSIONS: Our results suggest that percutaneous radiofrequency facet joint denervation with CMAPs monitoring is a safe, long-lasting, and effective treatment for chronic facet joint pain. CMAP monitoring may be useful as an objective index for facet denervation.

Operative treatment for scaphoid osteonecrosis (Preiser disease): salvage or excision? Report on two cases and a review of the literature.

Idiopathic avascular necrosis of the scaphoid, or Preiser disease, is a rare condition. Both the etiology and the pathology are still not well understood. We here present 2 cases with this disease and discuss the recommended treatment according to the stage of disease progression and by reference to previous studies in the literature. Similar to Kienböck disease, the recommended treatment should be selected according to the degree of disease progression. We believe that vascularized bone graft should be restricted to Herbert stage I or II cases with no evidence of radiocarpal arthritis or carpal instability. Our first case showed excellent revascularization following vascularized bone graft, as revealed by magnetic resonance image findings. The presence of arthrosis of the radiocarpal or mid-carpal joints is an indication for scaphoid excision with midcarpal fusion or proximal row carpectomy.

Treatment for Staphylococcus aureus infection following open wedge high tibial osteotomy using antibiotic-impregnated calcium phosphate cement.

UNLABELLED: This report describes a case of Staphylococcus aureus infection following open wedge high tibial osteotomy, which was successfully treated with by implant removal and replacement with antibiotic-impregnated calcium phosphate cement along with external fixation. The infection occurred 7 months after primary surgery and was treated by implant removal, debridement, external fixation, and application of vancomycin impregnated calcium phosphate cement to fill the defect. Subsequently, the infection resolved completely, and the osteotomy healed with no correction loss. Compared with conventional bone cement, calcium phosphate cement might be an optimal material for certain cases of infection after open wedge high tibial osteotomy because of its higher antibiotic retention, biocompatibility, osteoconductivity, and compatibility with heatlabile antibiotics. LEVEL OF EVIDENCE: V.