Association between preoperative neutrophil-lymphocyte ratio, uric acid, and postoperative delirium in elderly patients undergoing degenerative spine surgery.

PURPOSE: There are few reports regarding the association between the neutrophil-lymphocyte ratio (NLR), uric acid, and the development of postoperative delirium (POD) in patients who are undergoing spine surgeries. We investigated the associations between the NLR, uric acid as a natural antioxidant, and POD in elderly patients undergoing degenerative spine surgery. PATIENTS AND METHODS: This was a single-center, observational, and retrospective study conducted in Japan. We enrolled 410 patients who underwent degenerative spine surgery. POD was diagnosed after the surgeries by psychiatrists, based on the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). We performed a multivariable logistic regression analysis to clarify whether the NLR and uric acid values were associated with the development of POD in the patients. RESULTS: 129 of the 410 patients were excluded from the analysis. Of the 281 patients (137 females, 144 males), 32 patients (11.4%) were diagnosed with POD. The multivariable logistic regression analysis revealed that the preoperative uric acid level (adjusted odds ratio [aOR]: 0.67, 95% confidence interval [CI]: 0.49-0.90, p = 0.008) and age (aOR: 1.09, 95% CI: 1.02-1.16, p = 0.008) were significantly associated with POD. The preoperative NLR (aOR: 0.82, 95% CI: 0.60-1.13, p = 0.227) and antihyperuricemic medication (aOR: 0.97, 95% CI: 0.24-3.82, p = 0.959) were not significantly associated with POD. CONCLUSION: Our results demonstrated that in elderly patients undergoing degenerative spine surgery, the preoperative NLR was not significantly associated with POD, but a lower preoperative uric acid value was an independent risk factor for developing POD. Uric acid could have a neuroprotective impact on POD in patients with degenerative spine diseases.

Association of cervical atherosclerosis on Doppler ultrasonography and postoperative delirium in patients undergoing spinal surgery: a single-center, retrospective, observational study.

PURPOSE: This study aimed to evaluate the association between cervical atherosclerosis on Doppler ultrasonography and postoperative delirium (POD) in patients undergoing spinal surgery. METHODS: In this retrospective observational study using prospectively collected data, 295 consecutive patients aged > 50 years underwent spine surgery at a single institution between March 2015 and February 2021. Cervical atherosclerosis was defined as the intima-media thickness (IMT) of the common carotid artery (CCA) being ≥ 1.1 mm on pulsed-wave Doppler ultrasonography. Univariate and multivariate logistic regression analyses were performed with the prevalence of postoperative delirium as a dependent variable. Age, sex, body mass index, medical history, American Society of Anesthesiologists Physical Status (ASA-PS), CHADS2 score (an assessment score for stroke), instrumentation, duration of surgery, blood loss, and cervical arteriosclerosis were the independent variables. RESULTS: Twenty-seven patients of 295 (9.2%) developed delirium postoperatively. Forty-one (13.9%) of the 295 patients had cervical atherosclerosis. Their univariate analyses showed that age (P = 0.001), hypertension (P = 0.016), cancer (P = 0.046), antiplatelet agent use (P < 0.001), ASA-PS ≥ 3 (P < 0.001), CHADS2 score (P < 0.001), cervical atherosclerosis (P = 0.008), and right CCA-IMT (P = 0.007) were significantly associated with POD. However, multivariate logistic regression analyses showed older age (odds ratio [OR], 1.109; 95% confidence interval [CI] 1.035-1.188; P = 0.03) and antiplatelet agent use (OR, 3.472; 95% CI 1.221-9.870; P = 0.020) to be significantly associated with POD. CONCLUSIONS: There was a significant association between POD and the prevalence of cervical atherosclerosis using the univariate logistic regression analysis. Furthermore, multivariate logistic regression analyses showed that older age and antiplatelet agent use were independently associated with POD.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification.

PURPOSE: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). METHODS: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. RESULTS: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). CONCLUSION: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

A delayed diagnostic case with complaints of severe lower back pain and sciatic nerve symptoms caused by osteoid osteoma of the sacrum: A case report.

BACKGROUND: Osteoid sacral osteomas are rare. Patients present with severe lower back pain and, rarely, sciatic nerve symptoms. CASE PRESENTATION: Herein, we report a patient with delayed diagnosis with complaints of severe lower back pain and sciatic nerve symptoms compressed by a sacral osteoid osteoma. En bloc tumor resection was performed using computed tomography (CT)-based navigation. Complete resolution of symptoms was achieved immediately after surgery. CONCLUSION: Even if a patient with an osteoid osteoma has sciatic symptoms, spinal surgeons should recognize a subgroup of patients with unexpected spinal or pelvic tumors compressing the nerve root.

The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.

Usefulness of digital tomosynthesis in diagnosing cervical ossification of the posterior longitudinal ligament: a comparative study with other imaging modalities.

PURPOSE: The diagnosis and classification of ossification of the posterior longitudinal ligament (OPLL) can be difficult with radiography alone; therefore, computed tomography (CT) is also usually performed. There are many reports on the usefulness of digital tomosynthesis (DTS) for image analysis in orthopedics. This study aimed to compare the accuracy of DTS with radiography and CT for the diagnosis and classification of cervical OPLL (C-OPLL). MATERIALS AND METHODS: We included 31 patients with OPLL and 30 with cervical spondylotic myelopathy. The patients' cervical spine radiography, DTS, and CT images were each evaluated twice by three specialists and three residents. RESULTS: In the intra-observer reliability study, there was one observer with a fair level of kappa values for radiography and DTS among three residents. The kappa values for CT were the best for all observers. In the inter-observer reliability study, the interclass correlation coefficient (ICC) values were high for both diagnosis and classification by specialists at the almost perfect level for all three imaging modalities. On the other hand, the ICC values for both diagnosis and classification for radiography by the residents were lower than those for DTS and CT. CONCLUSIONS: This study revealed that DTS may be an alternative to CT for the diagnosis and classification of C-OPLL by specialists. Caution should be exercised in diagnosing and classifying C-OPLL using radiography and DTS by residents, and the use of CT is recommended.

Prevalence of whiplash injury and its association with quality of life in local residents in Japan: A cross sectional study.

BACKGROUND: Associations between whiplash injuries and quality of life (QOL) have been previously published by conducting surveys among patients. This study aimed to investigate the prevalence of whiplash injuries in a Japanese community, and the association between whiplash injuries and QOL was also determined. METHODS: In all, 1140 volunteers participated in this study, filled out a questionnaire about whether they had experienced a whiplash injury, or had any neck pain or neck-shoulder stiffness in the previous 3 months, and completed the Medical Outcomes Study 36-Item Short-Form Health Survey. QOL was evaluated from the eight domain scores, and the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores. We compared the characteristics, habits, history, medication, body mass index, and health-related QOL (eight domains, PCS and MCS scores) between the groups with whiplash injuries and no whiplash injuries for each sex. Multiple linear regressions with the forced-entry procedure were performed to evaluate the effects of a whiplash injury on the PCS and MCS. A p-value of <0.05 was considered statistically significant. RESULTS: The prevalence of whiplash injuries was 7.7% and 9.6% in men and women, respectively. The percentage of those who experienced whiplash injuries with symptoms persisting for more than 3 months was 34.3% and 24.2% in men and women, respectively. The prevalence of neck symptoms was significantly higher in the whiplash injury group than in the non-whiplash injury group. Multiple linear regression analysis showed that, although whiplash injuries were associated with poor health-related QOL in men, age was more associated with health-related QOL than whiplash injuries in both sexes. CONCLUSION: The prevalence of whiplash injuries was 7.7% and 9.6% in men and women in local residents in Japan, respectively. Whiplash injuries were poorly associated with a poor health-related QOL in men (P = 0.015).

Occupational ionizing radiation-induced skin injury among orthopedic surgeons: A clinical survey.

BACKGROUND: This study aimed to assess orthopedic surgeons' attitudes and behaviors toward occupational radiation exposure and investigate the prevalence of occupational radiation-induced skin injury among orthopedic surgeons. Similarly, risk factors for the presence of radiation-induced skin injury were investigated. METHODS: Overall, 108 orthopedic surgeons were administered self-reported questionnaires about occupational radiation exposure, and their hands were then photographed. Their fields of expertise were classified into spine, arthroplasty, sports medicine, hand, oncology, rheumatoid arthritis, pediatric orthopedic, and resident. Dermatologists evaluated the surgeons' skin conditions and classified into 3 grades of injury: grade 0, no clinical symptoms; grade 1, careful observation required; and grade 2, detailed examination required. Logistic regression analysis was performed to investigate the factors related to the presence of radiation-induced skin injury. Crude and adjusted logistic regression analysis using the backward stepwise selection method was similarly conducted. Receiver operating characteristic curve (ROC) analysis was performed to estimate the predictive power of exposure time, occupational period, and accumulated annual exposure time for radiation-induced skin injury. RESULTS: In total, 93.5% of the surgeons were careful about occupational radiation exposure, of which 76.8% used a dosimeter. Skin changes in the hands were self-reported by 42.5% of the surgeons, and radiation-induced skin injury was diagnosed in 31.4%. The accuracy of the self-reported skin changes was 100% for grade 2 and 61.5% for grade 1. Adjusted regression analysis showed that dermatologists' diagnosis-related factors were self-reported skin changes (odds ratio [OR] 3.1) and spine surgeons (OR 3.2). ROC analysis demonstrated that an occupational period >21 years and an accumulated exposure time >6696 min were considered risk factors, with ORs of 4.07 and 5.99, respectively. CONCLUSIONS: Orthopedic surgeons, particularly spine surgeons, should be regularly examined by dermatologists early in their careers for early detection of radiation-induced skin injury on the hands.

The impact of diabetes mellitus on spinal fracture with diffuse idiopathic skeletal hyperostosis: A multicenter retrospective study.

BACKGROUND: Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH. METHODS: We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups. RESULTS: DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference. CONCLUSIONS: In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.

The characteristics of the young patients with cervical ossification of the posterior longitudinal ligament of the spine: A multicenter cross-sectional study.

BACKGROUND: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. Although the patients with OPLL are more common in the 60s and 70s, we know that there are markedly young patients (e.g., early 40s). However, to the best of our knowledge, there is few reports characterize young patients with cervical OPLL in terms of the imaging features, subjective symptoms, and ADL problems. METHODS: This is the multicenter cross-sectional study. Two hundred and thirty-seven Japanese symptomatic patients with cervical OPLL confirmed by standard X-rays collected from 16 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament formed by the Japanese Ministry of Health, Labor and Welfare were recruited. Whole spine CT data as well as demographic data such as age, gender, patients-based evaluations, and the 36-item Short Form Health Survey (SF-36) were evaluated. RESULTS: Young group (≦ 45 years old) consisted of 23 patients (8 females and 15 males), accounting for 9.7% of the total. Their characteristics were high body mass index (BMI), significant involvement of trauma in the onset and deterioration of symptoms, and the predominance of thoracic OPLL. The patient-based evaluations did not show a significant difference between the young and non-young groups, or between the genders in the young group except for bodily pain (BP) of SF-36. Female patients in young group had significantly lower BP score of SF-36 than that of male in young group. CONCLUSIONS: Characteristics of young patients with cervical OPLL were high BMI, significant involvement of trauma in the onset and deterioration of symptoms, lower BP score of SF-36 in female, and the predominance of thoracic OPLL.

Effect of teriparatide on ligamentum flavum mesenchymal stem cells isolated from patients with ossification of the posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament (OPLL) within the spinal canal sometimes leads to severe myelopathy. Teriparatide (TPD) is a recombinant human parathyroid hormone (PTH) (1-34), which promotes osteogenesis of mesenchymal stem cells (MSCs) via PTH 1 receptor (PTH1R). Although ligamentum flavum (LF)-MSCs from patients with OPLL have a high osteogenic potency, the effect of TPD on them remains unknown. In this study, we determined PTH1R expression in LF-MSCs from patients with OPLL and investigated whether TPD promotes osteogenic differentiation in them. First, LF-MSCs were isolated from patients with OPLL and cervical spondylotic myelopathy (CSM) (controls). Cultured LF-MSCs were treated with different concentrations of TPD on days 0, 7, and 14. On day 21, osteogenic gene expression was quantified. Mineralization was measured based on optical density after Alizarin Red S staining. LF-MSCs from both groups expressed PTH1R at the same level. TPD did not enhance osteogenic gene expression and mineralization in LF-MSCs from both groups. TPD did not promote the osteogenic differentiation of LF-MSCs from patients with OPLL. Thus, it may be safe for patients with OPLL. However, further confirmation of our results with in vivo studies is necessary.

Cervical arteriosclerosis is associated with preoperative clinical symptoms in patients with cervical spondylotic myelopathy.

PURPOSE: This study aims to clarify the association between cervical spondylotic myelopathy (CSM) and cervical arteriosclerosis using ultrasonography that comprehensively includes spinal cord stenosis. METHODS: Eighty-two consecutive patients aged over 60 years who underwent spine surgery were divided into those with CSM (n = 31; CSM group) and those with lumbar spinal stenosis without cervical myelopathy (n = 51; LSS group). Maximum spinal cord compression (MSCC) was evaluated for cervical stenosis severity using magnetic resonance (MR) images. The intima-media thickness (IMT) of the common carotid artery (CCA) and pulsatility index (PI) of the bilateral internal carotid artery (ICA) and vertebral artery (VA) were evaluated for cervical arteriosclerosis using pulsed-wave Doppler ultrasonography. Symptom severity was evaluated using the Japanese Orthopaedic Association (JOA) score. Spearman's correlation coefficient was used to determine the relationship between the JOA score and MSCC or IMT and PI in each group. Stepwise multiple linear regression analyses were conducted with the JOA score as a dependent variable and age, sex, body mass index, cervical arteriosclerosis assessment, and MSCC as independent variables. RESULTS: Bilateral IMT and left-side ICA-PI were significantly negatively correlated with JOA scores in the CSM group (Right-CCA-IMT: R = - 0.412, Left-IMT: R = - 0.549, Left-ICA -PI: R = - 0.205, P < 0.05), but not in the LSS group. Multiple linear regression analyses showed that CCA-IMT was the strongest independent factor associated with the preoperative JOA score. CONCLUSIONS: Cervical arteriosclerosis was associated with preoperative clinical symptoms in CSM patients.

The effect of low back pain and neck-shoulder stiffness on health-related quality of life: a cross-sectional population-based study.

BACKGROUND: This cross-sectional study sought to determine the neck-shoulder stiffness/low back pain (NSS/LBP) comorbidity rate in a Japanese community population and to compare the quality of life (QOL) in individuals with comorbid NSS/LBP, asymptomatic individuals, and those with symptoms of NSS or LBP alone. METHODS: The sample included 1122 subjects (426 men; 696 women) with NSS and LBP symptoms in the previous 3 months, and were grouped according to NSS, LBP, comorbid NSS and LBP symptoms (Comorbid), or no symptoms (NP). They completed the MOS 36-Item Short-Form Health Survey (SF-36). Health QOL was evaluated by the eight domain scores and the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores after adjusting for age. The primary outcome was to examine the association between NSS/LBP, NSS, or LBP and bodily pain of the eight domains of SF-36. Secondary outcome was to compare health-related QOL among the four groups. RESULTS: Morbidity was 45.6% for NSS and 51.9% for LBP. Comorbidity affected 23% of men and 33% of women. Comorbid NSS/LBP, NSS, and LBP alone were independently associated with bodily pain after adjusting for potential confounders. Men who exhibited comorbidity had significantly lower MCS scores than asymptomatic men. Women who exhibited comorbidity and LBP had significantly lower MCS scores than those with no symptoms or NSS alone. Women who exhibited comorbidity had significantly lower MCS scores than those with no symptoms or LBP alone. CONCLUSIONS: Comorbidity of the two diseases is prevalent in 23% of the men and 33% of women in the Japanese sample. Although NSS, LBP, and comorbidity were independently associated with QOL in terms of pain, QOL was worse in individuals who exhibited comorbidity than in those without symptoms or with NSS alone.

Prevalence and associated factors of radiographic vertebral fractures in men: Rural population cross-sectional observation study in Japan.

BACKGROUND: Osteoporotic fractures constitute a major health concern in both women and men, particularly with the aging population. Many potential risk factors of vertebral fractures (VFx) have been identified in women, but not in men. Several reports have focused on the quality of life (QOL) of clinically diagnosed VFx, but not much has been reported on quantified QOL scores of incidental radiographic VFx in men. This cross-sectional study aimed to investigate the associated factors and the influence of incident radiographic VFx on QOL of men. METHODS: A total of 401 volunteer men aged 40 years or older (40-92 years) participated in this study. The mean age was 60.5 ± 11.8 years. Prevalent VFx were identified on the lateral lumbar spinal radiographs using the semiquantitative method. Bone mineral density, body composition, smoking, alcohol intake, past medical history, Mini-Mental State Examination, grip strength, gait speed, and biochemical markers were examined. QOL was evaluated using the 36-Item Short-Form Health Survey and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire. RESULTS: Of the 401 subjects, 35 men (8.7%) had the prevalence of VFx. After adjustment for age, the presence of VFx was significantly associated with IGF-1 (odds ratio 0.985; p = 0.02). QOL scores were not significantly associated with VFx after adjustment for age. CONCLUSIONS: IGF-1 is the mediator of growth hormone, and IGF-1 stimulates the proliferation, differentiation, and mineralization of osteoblastic cells. The prevalence of VFx in men was 8.7%, and IGF-1 was significantly lower in the VFx group than in the non-VFx group.

Understanding the effect of non-surgical factors in a transcranial motor-evoked potential alert: A retrospective cohort study.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Risk factors for delayed diagnosis of spinal fracture associated with diffuse idiopathic skeletal hyperostosis: A nationwide multiinstitution survey.

BACKGROUND: Patients with DISH are susceptible to spinal fractures and subsequent neurological impairment, including after minor trauma. However, DISH is often asymptomatic and fractures may have minimal symptoms, which may lead to delayed diagnosis. The purpose of this study was to identify risk factors for delayed diagnosis of spinal fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH). METHODS: The subjects were 285 patients with DISH surgically treated at 18 medical centers from 2005 to 2015. Cause of injury, imaging findings, neurological status at the times of injury and first hospital examination, and the time from injury to diagnosis were recorded. A delayed diagnosis was defined as that made >24 h after injury. RESULTS: Main causes of injury were minor trauma due to a fall from a standing or sitting position (51%) and high-energy trauma due to a fall from a high place (29%) or a traffic accident (12%). Delayed diagnosis occurred in 115 patients (40%; 35 females, 80 males; mean age 76.0 ± 10.4 years), while 170 (60%; 29 females, 141 males; mean age 74.6 ± 12.8 years) had early diagnosis. Delayed group had a significantly higher rate of minor trauma (n = 73, 63% vs. n = 73, 43%), significantly more Frankel grade E (intact neurological status) cases at the time of injury (n = 79, 69% vs. n = 73, 43%), and greater deterioration of Frankel grade from injury to diagnosis (34% vs. 8%, p < 0.01). In multivariate analysis, a minor trauma fall (OR 2.08; P < 0.05) and Frankel grade E at the time of injury (OR 2.29; P < 0.01) were significantly associated with delayed diagnosis. CONCLUSION: In patients with DISH, it is important to keep in mind the possibility of spinal fracture, even in a situation in which patient sustained only minor trauma and shows no neurological deficit. This is because delayed diagnosis of spinal fracture can cause subsequent neurological deterioration.

Accuracy of pedicle screw placement by fluoroscopy, a three-dimensional printed model, local electrical conductivity measurement device, and intraoperative computed tomography navigation in scoliosis patients.

INTRODUCTION: There are several assisted methods for the accurate placement of pedicle screw (PS), including fluoroscopy, a three-dimensional (3D) printed model, a local electrical conductivity measurement device (LECMD), and intraoperative computed tomography (CT) navigation. OBJECTIVES: This study aimed to investigate the accuracy of PS placement and clinical results using different assisted methods. METHODS: This study included 553 pedicle screws in 31 patients. We divided patients into the fluoroscopy (F) group (n = 79), 3D printed model and fluoroscopy (3D + F) group (n = 150), LECMD, 3D printed model, and fluoroscopy (LECMD + 3D + F) group (n = 171), and the intraoperative CT navigation (N) group (n = 153). We evaluated the operative time, intraoperative bleeding, number of fusion vertebrae, correction rate of the main curve, apical vertebral translation, grade of PS perforation (Grade 0: no perforation; Grade 1: < 2 mm; Grade 2: 2‒4 mm; Grade 3: > 4 mm), and accuracy of PS placement. RESULTS: The N group had a significantly longer operative time. There were no significant differences in the clinical results excluding the operative time. The accuracy of PS placement was 93.7%, 91.3%, 93.6%, and 93.5% in the F, 3D + F, LECMD + 3D + F, and N groups, respectively. The Grade 2 perforation rate was 2.5%, 0%, 0.6%, and 0.7% in the F, 3D + F, LECMD + 3D + F, and N groups, respectively. CONCLUSIONS: There were no significant differences in the accuracy of PS placement and clinical results excluding the operative time. The 3D printed model, LECMD, or intraoperative CT navigation would be useful to prevent Grade 2 perforation.

Can prophylactic C4/5 foraminotomy prevent C5 palsy after cervical laminoplasty with and without posterior instrumented fusion with maximal expansion?

OBJECTIVE: To prospectively examine whether laminoplasty with maximal expansion induces C5 palsy, even with prophylactic bilateral C4/5 foraminotomy. METHODS: Thirty-five consecutive patients with cervical myelopathy underwent laminoplasty (n = 19: LP group) or posterior decompression and fusion (n = 16: PDF group) with maximal expansion. Prophylactic bilateral C4/5 foraminotomy was performed alternately in consecutive five patients undergoing each type of surgery. In each type of surgery, the first and third consecutive five patients did not undergo foraminotomy (NF subgroup: 20 patients), while the second and fourth consecutive five patients underwent foraminotomy (F subgroup: 15 patients). The widths between the gutters was equivalent to the diameter of the spinal canal, and an inclination angle of the lamina of approximately 90° was created during laminoplasty. The incidence and severity of postoperative C5 palsy were investigated. Patients with a manual muscle testing score for the deltoid muscle and/or biceps brachii muscle of ≤ 2 were diagnosed with severe palsy. RESULTS: The respective incidences of C5 palsy in the F and NF subgroups were 33% and 20% in the LP group and 50% and 20% in the PDF group. Severe palsy occurred in 67% and 0% of patients who had developed palsy in F and NF subgroups, respectively, in the LP group, and in 100% of patients in the PDF group. Furthermore, 40% of the patients with severe palsy took more than 6 months to recover. CONCLUSIONS: Laminoplasty with maximal expansion induced C5 palsy in both the LP and PDF groups, even with the addition of prophylactic bilateral C4/5 foraminotomy.

Prevalence of cervical canal stenosis in farmers: Epidemiological study based on radiographic parameter of spinal cord injury patients.

BACKGROUND: Farming is one of the effective community activities for preventing the need for new long-term care insurance services. This study was conducted to compare spinal canal diameters between patients injured during orchard work (i.e., cultivating apples) and other situations that lead to cervical spinal cord injury without major fracture or dislocation and to investigate the frequency of cervical spinal canal stenosis among farmers in a Japanese community. METHODS: Subjects were 23 patients with cervical spinal cord injury without major fracture and dislocation. Charts and radiographs of these patients were retrospectively reviewed to evaluate the characteristics of the spinal cord injury. The spinal canal diameter at the injury level in the mid-sagittal plane of magnetic resonance imaging (MRI) and mechanism of injury were compared between patients injured by orchard work and other situations. Moreover, 358 Japanese general residents were evaluated for the prevalence of cervical canal stenosis using MRI and comparisons were made between farmers group and non-farmers group. RESULTS: Spinal canal diameters at the injury level were 5.8 ± 1.4 mm in patients injured during orchard work and 5.6 ± 1.0 mm in those injured in other situations; there were no differences between the two groups. Head contusion as mechanism of injury was more frequent in the orchard work group than in other situations group. Among farmers, the rate of spinal canal stenosis increased with age, and it was 62.3% in men and 66.2% in women. CONCLUSIONS: The frequency of cervical spinal canal stenosis was high with age regardless of farming work. In addition, head contusion might be a characteristic mechanism that causes spinal cord injury during orchard work. Therefore, screening of cervical degenerative conditions among farmers and education for prevention of cervical spinal cord injury during farming work are necessary.

The characteristics of the patients with radiologically severe cervical ossification of the posterior longitudinal ligament of the spine: A CT-based multicenter cross-sectional study.

BACKGROUND: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. We know that the size and distribution of the ossified lesions in patients with OPLL are different in each case. However, the characteristics of the patients with radiologically severe cervical OPLL remain unknown. METHODS: The participants of our study were symptomatic patients with cervical OPLL who were diagnosed by standard radiographs of the cervical spine. Whole-spine CT data and demographic data such as age and sex were obtained from 20 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. According to the number of the levels involved by OPLL, we stratified the patients into two subgroups: severe group (S-group) and non-severe group (NS-group) to delineate the characteristics of radiologically severe patients with cervical OPLL. We also evaluated the most compressed level and the degree of occupying ratio of cervical spinal canal by OPLL at the most compressed level. RESULTS: A total of 234 patients with a mean age of 65 years were recruited. The S-group consisted of 48 patients (21%, 12 females and 36 males) and the NS-group consisted of 92 patients (79%, 22 females and 70 males). The mean age of males in the S-group (68 years old) was significantly higher than that of males in the NS-group (64 years old); however there was no significant difference in the mean age in females between the S-group (69 years old) and the NS-group (66 years old). No significant difference of body mass index, ossification of the nuchal ligament-positivity and presence of diabetes mellitus were found between the S- and the NS-group. CONCLUSIONS: It is likely that the manner of extension of cervical OPLL is different between male and female patients.