Genetic insights into ossification of the posterior longitudinal ligament of the spine.

Ossification of the posterior longitudinal ligament of the spine (OPLL) is an intractable disease leading to severe neurological deficits. Its etiology and pathogenesis are primarily unknown. The relationship between OPLL and comorbidities, especially type 2 diabetes (T2D) and high body mass index (BMI), has been the focus of attention; however, no trait has been proven to have a causal relationship. We conducted a meta-analysis of genome-wide association studies (GWASs) using 22,016 Japanese individuals and identified 14 significant loci, 8 of which were previously unreported. We then conducted a gene-based association analysis and a transcriptome-wide Mendelian randomization approach and identified three candidate genes for each. Partitioning heritability enrichment analyses observed significant enrichment of the polygenic signals in the active enhancers of the connective/bone cell group, especially H3K27ac in chondrogenic differentiation cells, as well as the immune/hematopoietic cell group. Single-cell RNA sequencing of Achilles tendon cells from a mouse Achilles tendon ossification model confirmed the expression of genes in GWAS and post-GWAS analyses in mesenchymal and immune cells. Genetic correlations with 96 complex traits showed positive correlations with T2D and BMI and a negative correlation with cerebral aneurysm. Mendelian randomization analysis demonstrated a significant causal effect of increased BMI and high bone mineral density on OPLL. We evaluated the clinical images in detail and classified OPLL into cervical, thoracic, and the other types. GWAS subanalyses identified subtype-specific signals. A polygenic risk score for BMI demonstrated that the effect of BMI was particularly strong in thoracic OPLL. Our study provides genetic insight into the etiology and pathogenesis of OPLL and is expected to serve as a basis for future treatment development.

Return-to-Sport Rate, Type of Sport, Frequency of Participation, and Patient Satisfaction After Elective Spinal Surgery in the Elderly Population.

Background: The number of elderly sports participants is increasing, and the possibility of return to sport (RTS) has become an important part of surgical decision making in this population. Purpose: To investigate RTS after elective spinal surgery in elderly patients. Study Design: Case series; Level of evidence, 4. Methods: We enrolled patients aged ≥65 years with a history of preoperative or preinjury sports participation who underwent elective spinal surgery at a single institution between 2019 and 2021. At minimum 12-month follow-up, a questionnaire was administered to each participant to assess postoperative RTS, timing of return, frequency and type of pre- and postoperative activities, and satisfaction (scored 1-10). Descriptive statistical analyses were performed, and regression models were developed to examine the influence of age and sex, as well as surgical site, on RTS. Results: A total of 53 patients (mean ± SD age, 73.8 ± 5.2 years; 24 women) were included, and 23 (43.4%) returned to sports at a median 6 months (interquartile range, IQR, 2-6 months). The RTS rate by surgical site was 17 of 34 (50%) for the lumbar spine and 6 of 17 (35.3%) for the cervical spine. There were no statistically significant differences in RTS rate by surgical site, age, or sex. Overall, 6 of 17 patients returned to golf, 4 of 6 to dance, 2 of 5 to swimming, and 1 of 5 to tennis. Of patients who returned, 34.8% participated in sports 5 times per week and 26.1% participated 3 times per week. The median satisfaction score after RTS was 8 (IQR, 6-9). Conclusion: RTS after spinal surgery was achieved in 43% patients at 1-year minimum follow-up, with high satisfaction scores. More than half of the returning patients participated in sports activities ≥3 times per week.

Arthroscopic treatment for Morel-Lavallée lesion of the thigh: A case report and literature review.

INTRODUCTION: Morel-Lavallée lesion (MLL) is a posttraumatic closed degloving soft tissue injury, in which the subcutaneous tissues are separated from the underlying fascia. Surgical treatment is recommended if conservative management fails. The conventional surgical treatment for the lesion is surgical drainage and debridement. PRESENTATION OF CASE: A 51-year-old male patient presented with swelling of the right thigh incurred during a traffic accident. The lesion was diagnosed with MLL. The MLL was successfully treated with a minimally invasive arthroscopic treatment after failure of conservative treatment. The arthroscopic treatment was chosen because of the patient's comorbidity that posed a risk of surgical wound complications. In addition, negative pressure wound therapy (NPWT) was performed postoperatively to ensure healing and to prevent recurrence of the lesion. The patient was successfully treated and the healing of the lesion was also confirmed with MRI. DISCUSSION: In a patient with a risk of wound complications due to a comorbidity, this minimally invasive arthroscopic treatment is useful. In addition, NPWT was used to ensure healing and to prevent recurrence. Although the use of NPWT combined with endoscopic treatment has not been reported, additional NPWT reported in this case may be helpful to ensure healing. CONCLUSION: In case of MLL with a risk of surgical complications, the arthroscopic treatment is a reasonable method and achieves the goal of an open surgical debridement without increased morbidity.

D-dimer predicts pulmonary embolism after low-risk spine surgery.

INTRODUCTION: Pulmonary embolism (PE) is a risk of mortality following spine surgery. Many studies have demonstrated that deep venous thrombosis (DVT) may affect and actually advance to PE, but few studies have shown how venous thromboembolism (VTE), including PE and DVT, affect blood markers after spine surgery. In this study, we examined changes in blood markers with PE or DVT after low-risk spine surgery, namely cervical laminoplasty or lumbar laminectomy. METHODS: Seventy-two spine surgery patients were studied. A 16-row multidetector computed tomography was performed before and 3 d after the surgery. Patients with a history of cerebral vascular accident or arterial thrombotic episode or pre-surgical asymptomatic PE or DVT were excluded. Plasma levels of soluble fibrin monomer complex, D-dimer, plasminogen activator inhibitor type-1 (PAI-1), and white blood cell and platelet counts were measured preoperatively and postoperatively at days 1, 3, and 7. RESULTS: No patient developed symptomatic post-surgical VTE. Six patients with asymptomatic PE and six with asymptomatic DVT were detected post-surgery, including one patient with both. D-dimer postoperatively at days 3 and 7 was significantly higher in the post-op PE group than in the no-PE group. PAI-1 preoperatively was significantly higher in the DVT and VTE groups than in the no-DVT and no-VTE groups. CONCLUSIONS: Elevated D-dimer at postoperative days 3 and 7 is a predictive factor for the early diagnosis of PE after spine surgery. Moreover, elevated PAI-1 preoperatively is a predictive factor for the early diagnosis of DVT and VTE. Consequently, PE may occur through a pathway other than DVT.

The 25-question Geriatric Locomotive Function Scale predicts the risk of recurrent falls in postoperative patients with cervical myelopathy.

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.

Fall-related Deterioration of Subjective Symptoms in Patients with Cervical Myelopathy.

STUDY DESIGN: Retrospective multi-center study. OBJECTIVE: This study was conducted to clarify the incidence and neurological outcomes of fall-related deterioration of subjective symptoms in patients undergoing surgical treatment. SUMMARY OF BACKGROUND DATA: The evidence that minor trauma, including falls, increases the risk of worsening cervical myelopathy is insufficient. METHODS: A retrospective analysis of patients who had undergone surgery for cervical myelopathy at 12 participating institutes was conducted. Patients who had undergone surgery for symptomatic cervical myelopathy from January 2012 to December 2013 and completed at least 1-year follow-up were included in this study. Data were collected by chart review and a questionnaire that included numbers of recalled falls during the last preoperative year and first postoperative year, circumstances of falls, and whether the patient had experienced fall-related deterioration of subjective symptoms. RESULTS: A total of 360 eligible patients were recruited into the study. Of these, 177 (49%) reported at least one fall during the last preoperative year, and 105 (29%) experienced fall-related deterioration of subjective symptoms. Forty (11%) reported deterioration of numbness in the arms or legs, and 65 (18%) reported deterioration of motor deficits. Incidences of falls and fall-related deterioration of symptoms decreased significantly after surgery. Patients who experienced fall-related deterioration of motor deficits showed significantly worse surgical outcomes as assessed by Japanese Orthopaedic Association (JOA) score compared with those who did not experience deterioration. The optimal cut-off for preoperative JOA score in predicting an increased risk of fall-related deterioration in motor deficits was 8. CONCLUSION: Patients with cervical myelopathy commonly experienced preoperative fall-related deterioration of subjective symptoms, associated with significantly worse neurological outcomes. Surgical treatment significantly reduced the incidence of both falls and fall-related deterioration of subjective symptoms. LEVEL OF EVIDENCE: 4.

Progression of ossification of the posterior longitudinal ligament of the thoracic spine following posterior decompression and stabilization.

OBJECT: Despite its potential clinical impact, information regarding progression of thoracic ossification of the posterior longitudinal ligament (OPLL) is scarce. Posterior decompression with stabilization is currently the primary surgical treatment for symptomatic thoracic OPLL; however, it remains unclear whether thoracic OPLL increases in size following spinal stabilization. It is also unknown whether patients' clinical symptoms worsen as OPLL size increases. In this retrospective case series study, the authors examined the postoperative progression of thoracic OPLL. METHODS: Nine consecutive patients with thoracic OPLL who underwent posterior decompression and fixation with a minimum follow-up of 3 years were included in this study. Thin-slice CT scans of the thoracic spine obtained at the time of surgery and the most recent follow-up were analyzed. The level of the most obvious protrusion of ossification was determined using the sagittal reconstructions, and the ossified area was measured on the axial reconstructed scan at the level of the most obvious protrusion of ossification using the DICOM (digital imaging and communications in medicine) software program. Myelopathy severity was assessed according to the Japanese Orthopaedic Association (JOA) scale score for lower-limb motor function on admission, at postoperative discharge, and at the last follow-up visit. RESULTS: The OPLL area was increased in all patients. The mean area of ossification increased from 83.6 ± 25.3 mm(2) at the time of surgery to 114.8 ± 32.4 mm(2) at the last follow-up visit. No patients exhibited any neurological deterioration due to OPLL progression. CONCLUSIONS: The present study demonstrated that the size of the thoracic OPLL increased after spinal stabilization. Despite diminished local spinal motion, OPLL progression did not decrease or stop. Physicians should pay attention to ossification progression in patients with thoracic OPLL.

Preoperative predictors of patient satisfaction with outcome after cervical laminoplasty.

Study design Prospective cohort study. Objective The purpose of the present study was to identify the predictors of patient satisfaction with outcome after cervical laminoplasty for compressive cervical myelopathy. Methods A cohort of 143 patients with compressive myelopathy who underwent cervical double-door laminoplasty between 2008 and 2011 was studied prospectively. The principal outcome was patient satisfaction with outcome at 1 year after surgery. Patient satisfaction was graded on an ordinal scale from 1 to 7. Subjective health-related quality of life (QOL) and objective disease-specific outcome was measured by Short Form-36 (SF-36) and the Japanese Orthopaedic Association (JOA) score, respectively, before surgery and at 1-year follow-up. We evaluated the association between patient satisfaction at 1-year follow-up and various baseline parameters, including patient demographics, duration of symptoms, comorbidities, imaging findings, JOA score, and SF-36 scores. Results A total of 116 patients completed subjective and objective follow-up for a minimum of 1 year. Of 116 patients, 95 patients (81.9%) were satisfied with the outcome ("satisfied a little" or more). The unsatisfied group ("neutral" or less) showed significantly lower baseline SF-36 scores in bodily pain (BP), general health perceptions (GH), and vitality (VT) domains compared with the satisfied group. At the 1-year follow-up, SF-36 scores showed significant differences between the groups in all eight domains, whereas the JOA score showed no significant difference. Conclusions Lower baseline QOL measured by SF-36 scores, specifically in BP, GH, and VT domains, are associated with lower satisfaction with outcome after cervical laminoplasty.

Morphological characteristics of cervical spine in patients with athetoid cerebral palsy and the accuracy of pedicle screw placement.

STUDY DESIGN: A retrospective study. OBJECTIVE: To investigate the morphology of the cervical spine in patients with athetoid cerebral palsy (CP), and to evaluate its relationship with the breach of cervical pedicle screws. SUMMARY OF BACKGROUND DATA: Cervical pedicle screws have been increasingly used in surgery for patients with CP, but screw misplacement is not uncommon. Although the altered morphology of the cervical spine in patients with CP may result in this high breach rate, few studies have examined the cervical pedicle profile. METHODS: We retrospectively analyzed 31 patients with cervical myelopathy with CP, as well as 30 patients with cervical spondylotic myelopathy (CSM), who underwent posterior decompression surgery. The pedicle outer diameter, inner diameter, transverse angle and lateral mass deformity were investigated by obtaining preoperative computed tomographic scans. The accuracy of the placement of 56 pedicle screws used in fusion surgery for 12 patients with CP was also analyzed using postoperative computed tomographic scans. RESULTS: The outer diameter of the pedicle in CP was in the range from 3.3 to 9.6 mm, and was larger than that in CSM at all cervical levels except for C7. Pedicle sclerosis was more frequently observed in CP than in CSM (23% vs. 7.3%, P < 0.001). The transverse angle at C3 and C4 was larger, and lateral mass deformity was more frequently observed in CP than in CSM. The critical breach of pedicle screws in CP was found in 29%. A multivariate analysis revealed that pedicle sclerosis was associated with an increased risk of breach (odds ratio: 6.3; 95% confidence interval: 1.03-39.0; P = 0.047). CONCLUSION: The pedicle diameter in patients with CP was relatively large, but pedicle sclerosis, a wide transverse angle and lateral mass deformity were frequently observed. Sclerotic pedicles were associated with a higher risk of critical breach. LEVEL OF EVIDENCE: N/A.

Trauma-induced myelopathy in patients with retro-odontoid pseudotumour and ossification of the anterior longitudinal ligament: a report of two cases.

We report 2 cases of acute, progressive myelopathy after a fall in elderly patients who had a retroodontoid pseudotumour and extensive ossification of the anterior longitudinal ligament.

Pyogenic discitis due to Abiotrophia adiacens.

INTRODUCTION: Abiotrophia species have been referred to as nutritionally variant streptococci because of their fastidious nutritional requirements for growth. Abiotrophia species are difficult to identify with conventional solid culture. PRESENTATION OF CASE: A 48-year-old woman was admitted to our hospital with severe low back pain and body temperature of 38.2°C. Magnetic resonance imaging revealed edema and contrast enhancement of the L4 and L5 vertebral bodies with high signal intensity in the L3-4 and L4-5 intervertebral discs on the T2-weighted images. The patient underwent needle biopsy of the L3-4 disk. Cultures of disk biopsy samples and blood yielded gram positive cocci in short chains with scanty growth on chocolate agar. Further subculture with supplemented medium and subsequent 16S ribosomal RNA gene sequencing identified the pathogen as Abiotrhophia adiacens. The patient was treated with intravenous ampicillin. At 6-month follow-up, the patient was free of symptoms. DISCUSSION: Causative microorganisms remain unidentified in 25-40% of spinal infection cases. Abiotrophia species grow poorly on conventional solid media, and require pyridoxal or thiol group supplementation. Use of Brucella HK agar or GAM agar plate is helpful for detection of Abiotrophia species. We first confirmed the diagnosis by direct identification of Abiotrophia adiacens from infected disk. Abiotrophia species are one of the major pathogens of infective endocarditis accounting for 5% of cases. Considering their fastidious nature, it is likely that most cases of Abiotrophia discitis are falsely classified as culture-negative discitis; therefore, their role in pyogenic discitis may be underestimated. CONCLUSION: Subculture using nutritionally supplemented media is crucial for their identification.

Radiographical risk factors for major intraoperative blood loss during laminoplasty in patients with ossification of the posterior longitudinal ligament.

STUDY DESIGN: A retrospective multi-institutional study. OBJECTIVE: To clarify the distribution of intraoperative blood loss during cervical laminoplasty for ossification of the posterior longitudinal ligament (OPLL), and to identify the radiographical risk factors for the occurrence of major blood loss in patients with OPLL undergoing laminoplasty. SUMMARY OF BACKGROUND DATA: The incidence of major intraoperative blood loss during laminoplasty for OPLL is unknown. METHODS: All patients who underwent cervical laminoplasty for OPLL between April 2005 and March 2008 at 27 institutions across Japan were included in this analysis. We investigated the patients' characteristics and surgical data, and compared the radiographical characteristics of OPLL in patients with and without major blood loss. RESULTS: The estimated intraoperative blood loss was reported for 545 patients (429 male and 116 female; mean age, 62.7 yr). The mean intraoperative blood loss was 223 g (median, 130 g; range, minimal to 3350 g). Excluding 1 patient with intraoperative vertebral artery injury, major blood loss greater than 500 g was reported in 45 patients (8.3%). Patients with major blood loss were more likely to have neurological complications (5/45 vs. 12/499) and a longer hospital stay (29.5 d vs. 28.8 d) in comparison with those without major blood loss. The occupying ratio of OPLL was greater in the major blood loss group (48.3% vs. 42.2%; P = 0.02). A multivariate analysis revealed an occupying ratio of 60% or greater to be associated with an increased risk of major intraoperative blood loss (odds ratio, 2.4; 95% confidence interval, 1.1-5.3). CONCLUSION: Laminoplasty for OPLL is associated with a risk of major intraoperative blood loss, which can potentially give rise to devastating postoperative complications. An occupying ratio of 60% or greater is a risk factor for major blood loss during laminoplasty in patients with OPLL.

Perioperative complications of anterior cervical decompression with fusion in patients with ossification of the posterior longitudinal ligament: a retrospective, multi-institutional study.

BACKGROUND: Anterior decompression with fusion (ADF) for patients with cervical ossification of the posterior longitudinal ligament (OPLL) is reportedly associated with a higher incidence of complications than is laminoplasty. However, the frequency of perioperative complications associated with ADF for cervical OPLL has not been fully established. The purpose of this study was to investigate the incidence of perioperative complications, especially neurological complications, following ADF performed to relieve compressive cervical myelopathy due to cervical OPLL. METHODS: Study participants comprised 150 patients who had undergone ADF for cervical OPLL at 27 institutions between 2005 and 2008. Perioperative--especially neurological--complications occurring within 2 weeks after ADF were analyzed. Preoperative imaging findings, including Cobb angle, between C2 and C7 and occupying ratio of OPLL were investigated. Multivariate analysis with logistic regression was performed to identify independent risk factors for neurological complications. RESULT: Three patients (2.0 %) showed deterioration of lower-extremity function after ADF. One of the three patients had not regained their preoperative level of function 6 months after surgery. Upper-extremity paresis occurred in 20 patients (13.3 %), five of whom had not returned to preoperative levels 6 months after surgery. Patients with upper-extremity paresis showed significantly higher occupying ratios of OPLL, greater blood loss, longer operation times, fusion of more segments, and higher rates of cerebrospinal fluid leakage than those without paresis. Independent risk factors for upper-extremity paresis were a high occupying ratio of OPLL and large blood loss during surgery. CONCLUSIONS: The incidences of deterioration in upper- and lower-extremity functions were 13.3 % and 2.0 %, respectively. Patients with a high occupying ratio of OPLL are at higher risk of developing neurological deterioration.

Ultrasonographic quantification of spinal cord and dural pulsations during cervical laminoplasty in patients with compressive myelopathy.

PURPOSE: Pulsatile movements of the dura mater have been interpreted as a sign that the cord is free within the subarachnoid space, with no extrinsic compression. However, the association between restoration of pulsation and adequate decompression of the spinal cord has not been established. The present study investigated the relationship between the extent of spinal cord decompression and spinal cord and dural pulsations based on quantitative analysis of intraoperative ultrasonography (US). METHODS: Eighty-five consecutive patients (55 males, 30 females; mean age, 64 ± 13 years) who underwent cervical double-door laminoplasty to relieve compressive myelopathy were enrolled. Spinal cord decompression status was classified as: Type 1 (non-contact), the subarachnoid space was retained on the ventral side of the cord, Type 2 (contact and apart), the cord showed both contact with and separation from the anterior element of the cervical spine, or Type 3 (contact), the cord showed continuous contact with the anterior element of the cervical spine. Spinal cord and dura mater dynamics were quantitatively analyzed using automatic video-tracking software. Furthermore, the intensity of spinal and dural pulsation was compared with the recovery of motor function at 1 year after surgery as measured by increase in the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). RESULTS: Spinal cord pulsation amplitude ranged from 0.01 to 0.84 mm (mean 0.30 ± 0.16 mm) and dural pulsation amplitude ranged from 0.01 to 0.38 mm (mean 0.14 ± 0.08 mm). Average spinal cord pulsation amplitude in Type 2 patients was significantly larger than that in the other groups, whereas, average dural pulsation amplitudes were similar for all three groups. There was a significant correlation between spinal cord and dural pulsation amplitudes in Type 1 patients, but not in Type 2 or Type 3 patients. Type 3 patients showed a particularly poor correlation between spinal cord and dural pulsations. Spinal cord pulsation amplitude was moderately correlated with the recovery of motor function evaluated by JOACMEQ. CONCLUSION: The present results suggest that restoration of dural pulsation is not an adequate indicator of sufficient decompression of the spinal cord following a surgical procedure.

Histological investigation of resected dura mater attached to spinal meningioma.

STUDY DESIGN: Histological observational study of patients with spinal meningioma. OBJECTIVE: To clarify the status of tumor cell invasion into the dura mater and to provide fundamental information for appropriate management of dural attachment. SUMMARY OF BACKGROUND DATA: Histological appearance of the dura attached to spinal meningioma has not been sufficiently evaluated. METHODS: Dura mater resected in a Simpson Grade 1 manner from 25 consecutive patients with spinal meningiomas (World Health Organization grade 1) was histologically observed to determine the status of tumor cell invasion. As no clear borders such as a tumor capsule between tumor and dura mater were observed, histological findings of the dura mater were classified into the following 3 categories: grade 1, no dural invasion, with only inflammation of the dura; grade 2: dural invasion below the zone between the inner and outer layers; and grade 3, dural invasion into or over the zone between the inner and outer layers (full-thickness invasion). RESULTS: In our microscopic study, 19 of the 25 cases of spinal meningioma showed evidence of dural invasion and 15 cases showed full-thickness invasion. CONCLUSION: This histological investigation of resected dura mater attached to spinal meningioma showed a high rate of full-thickness tumor invasion into the dura mater.

Natural course and prognostic factors in patients with mild cervical spondylotic myelopathy with increased signal intensity on T2-weighted magnetic resonance imaging.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: To investigate natural course and prognostic factors in patients with mild forms of cervical spondylotic myelopathy (CSM), focusing on intramedullary increased signal intensity (ISI) on T2-weighted magnetic resonance imaging. SUMMARY OF BACKGROUND DATA: Long-term natural course of mild forms of CSM, especially with ISI on magnetic resonance imaging, remains uncertain. METHODS: Patients with CSM who visited our institution between 1992 and 2004 and did not undergo surgery at first visit were retrospectively reviewed. The inclusion criteria were as follows: (1) motor function Japanese Orthopedic Association scores of 3 or more in both upper and lower extremities and (2) cervical spinal cord compression with ISI on T2-weighted magnetic resonance imaging. There were 45 patients, with a mean follow-up period of 78 months (range, 24-208). We investigated long-term natural history by setting the timing of conversion to surgery due to neurological deterioration as an end point. We further compared prognostic parameters between patients who converted to surgery and those who continued to be followed up nonsurgically. RESULTS: Sixteen patients gradually deteriorated and underwent decompression surgery, whereas 27 patients did not. Apart from these, 2 patients with acute spinal cord injury after minor trauma underwent surgery. Kaplan-Meier survival analysis revealed that 82% or 56% of patients did not require surgery 5 or 10 years after the initial treatment, respectively. As for prognostic factors, Cox proportional hazard analysis revealed that total cervical range of motion (hazard ratio: 3.25), segmental kyphosis in the maximum compression segment (hazard ratio: 4.51), and local slip (hazard ratio: 4.67) were statistically significant. CONCLUSION: Fifty-six percent of patients with clinically mild CSM with ISI had not deteriorated or undergone surgery at 10 years. Large range of motion, segmental kyphosis, and instability at the narrowest canal were considered to be adverse prognostic factors.

Development of a screening tool for risk of locomotive syndrome in the elderly: the 25-question Geriatric Locomotive Function Scale.

OBJECTIVE: To evaluate the reliability and validity of a new questionnaire, the 25-question Geriatric Locomotive Function Scale (GLFS-25), for early detection of locomotive syndrome. METHODS: This new screening tool was designed to detect Japanese individuals under high-risk conditions who may soon require care services because of problems of the locomotive organs. Content validity, construct validity, criterion validity, internal-consistency reliability, and reproducibility (test-retest reliability) were examined using psychometric analysis, and a cutoff score to detect locomotive syndrome was determined. To investigate construct validity of the GLFS-25 and determine the cutoff score, the Akaike Information Criteria (AIC) were used. RESULTS: Study 1 analyzed 711 Japanese elderly people ≥65 years old. No floor or ceiling effects were included in the GLFS-25. Internal consistency was confirmed by a Cronbach's α reliability coefficient of 0.961. As for the association between the GLFS-25 and European Quality of Life Scale-5 Dimensions (EQ-5D), Spearman's correlation coefficient was 0.85 (P < 0.001), showing excellent concurrent validity of the GLFS-25. Categorical principal component analysis showed that the construct structure consisted of one item cluster or the GLFS-25 was unifactorial. The AIC showed that one cluster of seven items was located in the center, with significant associations with the other five clusters. In study 2, 205 individuals were analyzed, and the test-retest interclass correlation was satisfactory (range 0.712-0.924). The cutoff score for identifying locomotive syndrome was set at 16. Validity and reliability of this new measurement were psychometrically confirmed as sufficient. CONCLUSIONS: The GLFS-25 offers a valid and reliable questionnaire scale for detecting locomotive syndrome in elderly Japanese individuals.

[Use of Parker Flex-Tip tracheal tube in a patient with Kniest dysplasia].

A 37-year-old man with Kniest dysplasia and thoracic myelopathy was scheduled for T3-12 laminectomy. Kniest dysplasia is a severe chondrodysplasia characterized by short trunk and limbs. Awake fiberoptic intubation was attempted to prevent airway obstruction because we had predicted his difficult airway. During fiberoptic tracheal intubation, we easily succeeded in the insertion of the fiberscope itself into the trachea, but were not able to insert the tip of a reinforced tube into the trachea, because the tip of the reinforced tube impinged on laryngeal structures. We succeeded in placing the Parker Flex-Tip tracheal tube into the trachea. We considered that the Parker Flex-Tip tube, having a tip that reduces the gap between the fiberscope and the inside of the tube, resulted in success of the passage of the tube into the trachea during fiberoptic intubation.

Dumbbell-type juvenile xanthogranuloma in the cervical spine of an adult.

Adult cases with isolated juvenile xanthogranuloma of the central nervous system are very rare. We report a case with dumbbell-type juvenile xanthogranuloma in the cervical spine. A 38-year-old man presented with moderate numbness of the right ring finger and right little finger and weakness of the right grip. Magnetic resonance imaging (MRI) showed an intra-spinal mass extending into the paravertebral area. The spinal cord was compressed by the lesion, which was isointense with the spinal cord on both T1- and T2-weighted imaging. Homogenous enhancement was observed after gadolinium administration. These findings favored a preoperative diagnosis of a rare tumor, rather than tumor of the nervous system. Complete surgical removal of the tumor was performed through hemilaminectomy combined with facetectomy between C7 and T1. Histological examination and immunohistochemical testing led to a diagnosis of juvenile xanthogranuloma. Two years after complete resection, MRI showed no recurrence. This appears to represent the first report of dumbbell-type juvenile xanthogranuloma in the cervical spine. Total removal of such lesions is recommended because of the high potential risk of tumor recurrence around the central nervous system.