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Intraoperative neuromonitoring (IONM) is important for detecting neurological dysfunction, allowing for intervention and reversal of neurological deficits before they become permanent. Of the several IONM modalities, transcranial electrical stimulation of motor-evoked potential (TES-MEP) can help monitor the activity in the pyramidal tract. Surgery- and non-surgery-related factors could result in a TES-MEP alert during surgery. Once the alert occurs, the surgeon should immediately intervene to prevent a neurological complication. However, TES-MEP monitoring does not provide sufficient data to identify the non-surgery-related factors. Therefore, this study aimed to identify and describe these factors among TES-MEP alert cases.In this multicenter study, data from 1934 patients who underwent various spinal surgeries for spinal deformities, spinal cord tumors, and ossification of the posterior longitudinal ligament of the spine from 2017 to 2019 were collected. A 70% amplitude reduction was set as the TES-MEP alarm threshold. All surgeries with alerts were categorized into true-positive (TP) and false-positive (FP) cases according to the assessment of immediate postoperative neurological deficits.In total, TES-MEP alerts were observed in 251 cases during surgery: 62 TP and 189 FP IONM cases. Overall, 158 cases were related to non-surgery-related factors. We observed 22 (35.5%) TP cases and 136 (72%) FP cases, which indicated cases associated with non-surgery-related factors. A significant difference was observed between the two groups regarding factors associated with TES-MEP alerts (p 0.01). The ratio of TP and FP cases (related to non-surgery-related factors) associated with TES-MEP alerts was 13.9% (22/158 cases) and 86.1% (136/158 cases), respectively.Non-surgery-related factors are proportionally higher in FP than in TP cases. Although the surgeon should examine surgical procedures immediately after a TES-MEP alert, surgical intervention may not always be the best approach according to the results of this study.

Background Numbness in the soles of both feet at rest or bowel/bladder dysfunction can occur in patients with lumbar spinal stenosis (LSS), especially in patients with cauda equina lesions. The purpose of this study was to clarify the relationship between cauda equina symptoms at rest and quality of life (QOL) in LSS patients using standardized questionnaires developed for the Japanese population. Methods A survey was conducted in 564 hospitals and general practice clinics nationwide from December 1, 2011 to December 31, 2012. All patients who visited hospital or clinic because of low back pain were included. Patients were diagnosed with LSS using the LSS-Diagnostic Support Tool (LSS-DST), and the severity of the disease was measured using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) for quality of life. Presence of both sole numbness and/or bowel/bladder dysfunction were determined by medical interview. 3647 patients were diagnosed with LSS according to the results of the LSS-DST. 1294 of these patients (35.5%) had symptoms at rest. Of these patients, 359 patients with sole numbness, 135 patients with bowel/bladder dysfunction, and 52 patients with both numbness and bowel/bladder dysfunction were compared to the patients without rest symptoms (n = 2182). Comparisons between groups with or without sole numbness and bowel/bladder dysfunction were performed using statistical analysis of JOABPEQ responses in the categories of pain-related disorder, lumbar spine disorder, gait disturbance, social life disturbance, and psychological disorder. Results All groups with sole numbness and/or bowel/bladder dysfunction had statistically lower (worse) scores in all categories of the JOABPEQ compared to the group without these symptoms at rest. Conclusion LSS patients having numbness in the soles of both feet at rest or bowel/bladder dysfunction had lower measurements of QOL and activities of daily living than those patients without symptoms at rest. These symptoms appear to be related to QOL of LSS patients.

Neck pain around shoulder girdle is a common symptom encountered at orthopedic clinics. It is usually caused by cervical spondylosis or sprain and related radiculopathies. However, in rare cases, patients suffering from neck pain may develop a serious condition, for example tetraplegia including spinal cord insult. Lemierre’s syndrome or necrobacillosis often causes neck pain. It is characterized by acute anaerobic bacterial infection in the oropharyngeal region followed by septic metastasis towards various distant organs [1–5]. Twenty cases were reported by Lemierre in 1936, and his report warned of high mortality as a result of this syndrome [6]. This anaerobic infection is usually caused by Bacteroides families, especially, Fusobacterium necrophorum, which are often found in oral cavities and alimentary tracts; parapharyngeal space infection then leads to thrombophlebitis of the internal jugular veins [1–5]. Furthermore, some literature has warned that progress of this infection sometimes leads to the development of vertebral osteomyelitis with spinal cord insult [7, 8], occasionally even resulting in death [1, 3, 5]. Hence, orthopedic clinicians must keep in mind this syndrome when they see patients who complain of neck pain, because this terrible but rare infection may arise in the parapharyngeal region in the early stages of the disease. In this paper, we report on how we encountered a patient with neck pain who was overlooked at the beginning of infection, and who ended up developing tetraplegia caused by widespread epidural abscess in the spinal canal accompanied by metastatic lung infection.

1 Laboratory of Statistics, Osaka City University Faculty of Medicine, Osaka, Japan 2 Department of Orthopaedic Surgery, Keio University, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan 3 Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Japan 4 Department of Orthopaedic Surgery, School of Medicine, Fukushima Medical University, Fukushima, Japan 5 Department of Orthopedic Surgery, Nippon Medical School, Tokyo, Japan 6 Department of Orthopaedic Surgery, The University of Tokyo, Tokyo, Japan 7 Department of Orthopaedic Surgery, Iwate Medical University School of Medicine, Morioka, Japan 8 Department of Orthopaedic Surgery, Saitama Medical School. Saitama, Japan 9 Department of Orthopedic Surgery, Yamaguchi University School of Medicine, Yamaguchi, Japan 10 Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan 11 Department of Orthopaedics, Kochi Medical School, Kochi, Japan 12 Department of Orthopaedic Surgery, Hoshigaoka Koseinenkin Hospital, Osaka, Japan 13 National Hospital Organization, Osaka-Minami Medical Center, Osaka, Japan 14 Department of Internal Medicine, Houai Hospital, Osaka, Japan 15 Department of Public Health, Osaka City University Faculty of Medicine, Osaka, Japan

Background The Japanese Orthopaedic Association decided to revise the JOA score for low back pain and to develop a new outcome measure. In February 2002, the first survey was performed with a preliminary questionnaire consisting of 60 evaluation items. Based on findings of that survey, 25 items were selected for a draft of the JOA Back Pain Evaluation Questionnaire (JOABPEQ). The second survey was performed to confirm the reliability of the draft questionnaire. This article further evaluates the validity of this questionnaire and establishes a measurement scale. Methods The subjects of this study consisted of 355 patients with low back disorders of any type (201 men, 154 women; mean age 50.7 years). Each patient was asked to fill in a self-administered questionnaire. Superficial validity was checked in terms of the completion rate for filling out the entire questionnaire. Factor analysis was then performed to evaluate the validity of the questionnaire and establish a measurement scale. Results As a result of the factor analysis, 25 items were categorized into five factors. The factors were named based on the commonality of the items: social function, mental health, lumbar function, walking ability, and low back pain. To establish a measurement scale for each factor, we determined the coefficient for each item so the difference between the maximum factor scores and minimum factor scores was approximately 100. We adjusted the formula so the maximum for each factor score was 100 and the minimum was 0. Conclusions We confirmed the validity of the JOA Back Pain Evaluation Questionnaire and est ablished a measurement scale.

BackgroundTo establish a patient-oriented outcome measure for cervical myelopathy, a subcommittee of the Japanese Orthopaedic Association (JOA) developed a new scoring system to evaluate the overall clinical status of patients, which could be completed by patients themselves. The subcommittee completed three large-scale studies to select and modify questions derived from various preexisting outcome measures including Short Form-36, and then finalized and validated the questionnaire, which comprised 24 questions.MethodsThe finalized questionnaire was administered to 369 patients with cervical myelopathy due to disc herniation, spondylosis, or ossification of posterior longitudinal ligament by randomly selected board-certified spine surgeons. Patients with different severities of myelopathy were included to insure accuracy and responsiveness of this questionnaire against patients’ different neurological status.ResultsData of 236 patients were employed and were subjected to rigorous statistical analyses. There was no question that was difficult to answer and distribution of answers for each question was not concentrated to one choice, indicating the appropriateness of all 24 questions. Results of factor analysis suggested that the 24 questions could be divided into five different factors or functional domains. The factors were defined as follows: factor 1, lower extremity function; factor 2, quality of life; factor 3, cervical spine function; factor 4, bladder function; and factor 5, upper extremity function. Finally, equations that would yield scores for the five factors were assembled. The score to be used to represent the degree of patients’ disability or status in each domain can be calculated by multiplying prefixed numbers of selected answers to questions by preassigned coefficients. Coefficients were defined to make the minimum score 0 and the maximum score 100.ConclusionsWe have successfully established a questionnaire that is able to demonstrate the status of patients suffering cervical myelopathy from five different aspects represented by five intuitive numerical scores. The final issue to be confirmed is the responsiveness of this questionnaire to changes in patients’ status after various surgical and nonsurgical treatments.

Background The project to develop a new Japanese Orthopaedic Association (JOA) score rating system for low back disorders, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), is currently in progress. Part 1 of the study selected 25 “candidateȝ items for use on the JOABPEQ. The purpose of this current Part 2 of the study was to verify the reliability of the questionnaire. Methods A total of 161 patients with low-back disorders of any type participated in the study. Each patient was interviewed twice at an interval of 2 weeks using the same questionnaire. The reliability of the questionnaire was evaluated by determining the extension of the kappa and weighted kappa coefficients. Results Both kappa and weighted kappa were more than 0.50 for all but one item, which was 0.48. The lower 95% confidence interval exceeded 0.4 in all but two items, which was 0.39. This implied that the test–retest reliability of JOABPEQ was acceptable as a measure of outcome. Conclusions The tentative questionnaire of the JOABPEQ with 25 items was confirmed to be reliable enough to describe the quality of life of patients who suffer low back disorders.

BackgroundThe manner of measuring the outcome of cervical myelopathy must be patient-oriented and have sufficient reliability and validity. The current Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy is widely used but has not met this requirement. The first- and second-round surveys established 24 items for inclusion on a new questionnaire for cervical myelopathy. The purpose of this study (the third-round survey A) was to confirm the reproducibility of patient responses to the selected questions.MethodsA total of 201 patients with cervical myelopathy and with no change of symptoms between the two interviews were included. Each patient was interviewed twice using the same questionnaire at an interval of 4 weeks. The reliability of the questionnaire was evaluated by determining the extension of the weighted kappa coefficients.ResultsThe weighted kappa coefficient for each item was >0.4, confirming that the test–retest reliability was acceptable.ConclusionsThe newly developed JOA Cervical Myelopathy Evaluation Questionnaire was proven to have sufficient reliability.

Degenerative spondylolisthesis of the cervical spine has received insufficient attention in contrast to that of the lumbar spine. The authors analyzed the functional significance of anterior and posterior degenerative spondylolisthesis (anterolisthesis and retrolisthesis) of the cervical spine to elucidate its role in the development of cervical spondylotic myelopathy (CSM) in the elderly.A total of 79 patients aged 65 or older who eventually had surgical treatment for CSM were evaluated radiographically.Altogether, 24 patients (30%) had displacement of 3.5 mm or more (severe spondylolisthesis group), 31 had displacement of 2.0-3.4 mm (moderate spondylolisthesis group), and 24 had less than 2.0 mm displacement (mild spondylolisthesis group). The severe spondylolisthesis group consisted of 14 patients with anterolisthesis (anterolisthesis group) and 10 patients with retrolisthesis (retrolisthesis group). Patients with severe spondylolisthesis had a high incidence (93%) of degenerative spondylolisthesis at C3/4 or C4/5 and significantly greater cervical mobility than those with mild spondylolisthesis. The anterolisthesis group, but not the retrolisthesis group, had a significantly wider spinal canal than the mild spondylolisthesis group, although the degree of horizontal displacement and cervical mobility did not differ significantly between the anterolisthesis and retrolisthesis groups. Severe cord compression seen on T1-weighted magnetic resonance imaging (MRI) scans and high-intensity spinal cord signals seen on T2-weighted MRI scans corresponded significantly to the levels of the spondylolisthesis.Degenerative spondylolisthesis is not a rare radiographic finding in elderly patients with CSM, which tends to cause intense cord compression that is seen on MRI scans. Greater mobility of the upper cervical segments may be a compensatory reaction for advanced disc degeneration of the lower cervical segments, leading to the development of degenerative spondylolisthesis. With a similar degree of displacement, anterolisthesis tends to have a greater impact on the development of CSM than retrolisthesis.

The Japan Spine Research Society carried out a nationwide survey on complications of the spine, enrolling a total of 16 157 patients who had undergone spine surgery in 196 institutes in the 1-year period from January to December 2001. Diseases, surgical procedures, and complications were surveyed in detail. Forty-nine percent of patients were aged 60 years or older, which was remarkably increased in comparison with the percentage reported by the 1994 survey (37.3%). The number of cases with degenerative spinal diseases comprised 78.2% of the total number of spine surgery cases. The percentage of patients with stenosis was the greatest (38.5%), reflecting the increase in the elderly population undergoing spine surgery. Spinal instrumentation was used with 5497 patients (34.0%). The frequency of its use was much greater than that reported in 1994 (27.0%). The pedicle screw was the most frequently used instrument (54.6%). The use of spinal instrumentation greatly increased for spinal deformity, trauma, and tumors. Posterior lumbar interbody fusion has been increasingly used in cases of lumbar degenerative disease. Complications of spinal surgery were reported in 1383 patients (8.6%). The incidence of complications associated with instrumentation surgery was 12.1%, being twice as much as that associated with noninstrumentation surgery (6.8%).

It is generally accepted that osteoarthritis of the hip is a common cause of pain and disability. In clinical practice, a variety of conservative and surgical methods are available for patients with hip osteoarthritis. Nonsurgical interventions are recommended as the first-line treatment for hip osteoarthritis [1]. As one of the conservative therapies used in nonsurgical interventions, physical therapy, including hip traction and stretching, has been shown to reduce pain and improve hip function in patients with hip osteoarthritis [2]. Pain originating from the hip joint is distributed not only in the groin area but also in the buttocks, anterior thighs, and knees [3, 4]. Knee pain arising from the hip joint is one of the characteristics of referred pain in hip osteoarthritis. However, the effects of physical therapy on referred pain have not been well documented. We developed an original hip traction technique using a lumbar traction machine. Of note, patients treated with this method experienced immediate relief of referred knee pain. This study describes the results of immediate relief of referred knee pain because using hip traction.

We conducted an experimental study using rabbits to determine the effect of injection of calcium phosphate cement (CPC) through a small cortical window on the torsional strength of the long bone. A drill hole created in the femoral shaft and medullary curettage before CPC injection simulates the clinical procedure for managing benign bone tumors. Torsional loading always produced a spiral fracture through the drill hole. The CPC-treated femurs, but not the polymethylmethacrylate-treated femurs, tolerated greater torsional loads and had greater energy absorption to failure at 24 h and 2 weeks postoperatively compared with the con-tralateral sham-operated femurs. These two parameters, however, were only 54% and 26%, respectively, of those in normal femurs at 24 h, but they were 71% and 51% of those in normal femurs at 12 weeks. Histologic sections demonstrated progressive covering of the drill hole by new bone in the CPC-treated specimens and invagination by newly formed cortical bone into the medullary cavity following sham operation. CPC increases the torsional strength of the long bones immediately after injection, although not sufficiently to preclude the need for external fixation in clinical applications. Better management of the cortical defect is needed to further improve torsional strength.

Previous studies of trunk muscle strength in patients with chronic low back pain (CLBP) have mainly reported on patients aged younger than 40 years. However, no such investigation has yet been done in middle-aged patients. Trunk muscle strength and the effect of trunk muscle exercises were investigated in patients with CLBP aged more than 40 years. Trunk muscle strengths were measured in a LBP group (52 patients) and a control group (60 volunteers) and the results for the two groups were compared. The LBP group was divided into three subgroups. Group A had only age-related spondylosis and group B had disk herniation and spondylolisthesis with age-related spondylotic change. Both these groups were able to continue exercises. Group C was made up of patients who had abandoned the exercise program. Trunk muscle strength and symptoms were assessed in each group. Both flexion and extension strength were decreased in the LBP group compared with the control group, with the reduction in extension strength being most marked. In both groups A and B, muscle strength increased and clinical symptoms improved. In contrast, no change was seen in group C. In older patients with CLBP, reduction of muscle strength was more marked in the spinal extensors than in the spinal flexors. It was confirmed that trunk muscle strengthening exercises are useful for increasing muscle strength and improving symptoms in such patients.

We developed a titanium fiber mesh block (TFMB) to use as an alternative to autogenous bone, grafts for vertebral interbody fusion. In in vitro tests, we measured the surface pore size and conducted weight loading tests of TFMB with porosities of 50% and 60%. For invivo testing, we grafted TFMB in 11 mongrel dogs for intervertebral fusion and evaluated bone ingrowth into the grafts and the bonding of TFMB with bone. The mean surface pore size was 375±289 μm for 50% porosity TFMB and 445±440 μm for 60% porosity TFMB. In the in vitro weight loading test, 60% porosity TFMB showed 50%–60% of the elastic modulus of 50% porosity TFMB, and both materials showed a similar yielding load. After the grafting of 60% porosity TFMB, bone in-growth occurred to a depth of 2.3 mm at 3 months and to a depth of 3.6 mm at 6 months; while the values were 0.7 mm and 1.5 mm, respectively, in 50% porosity TFMB. In a push-out test conducted 6 months after grafting, 50% and 60% porosity TFMB showed similar bone bonding strengths. These results suggest that 60% porosity TFMB implant will be suitable to using for spinal interbody fusion.

BackgroundThere is no widely accepted objective evaluation for lumbar spine disorders. New outcome measures should be patient-oriented and should measure symptoms and self-reported functional status in multiple dimensions. The aim of this study was to identify items to be included in the disease-specific quality of life (QOL) questionnaire for the assessments of patients with lumbar spine disorders.MethodsThe draft of the QOL questionnaire that consisted of a total of 60 items, including 24 items derived from the Japanese version of the Roland Morris Disability Questionnaire (RDQ) and 36 items derived from the Japanese version of Short Form 36 (SF-36), were administered to patients and controls. After obtaining written informed consent, the following data were collected from the patient group (n = 328) and the control group (n = 213): (1) background characteristics, including age, diagnosis, Japanese Orthopaedic Association (JOA) score, and finger to floor distance; (2) responses to the questionnaire; (3) the identification rate by discrimination analysis to select the candidates for adoption and by adopting explanatory variables. The items to be excluded were determined by examining the explanatory variables, which were selected after the discrimination analysis, by setting the candidate to-be-excluded items as an objective variable.ResultsBased on the distribution of the responses, two items, RDQ-15 and RDQ-19, were excluded. From the results of the correlation coefficient calculation for each question in the patient group, 33 items were excluded and 27 candidate items were adopted. Based on the adoption explanatory variable used in the discrimination analysis, 25 of the 27 candidate items for adoption were accepted.ConclusionsThis study identified the 25 specific questionnaire items that should be included in the questionnaire to evaluate QOL of patients with various lumbar spine disorders.