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Study Design A retrospective cohort study. Purpose To investigate the sagittal plane configuration of the entire spine and its association with the risk of adjacent segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF). Overview of Literature Although PLIF has demonstrated satisfactory clinical outcomes, it is associated with ASD. However, the geometric mechanical changes that contribute to the occurrence of ASD are not well characterized. Methods Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.

Introduction: Chemonucleolysis with condoliase is a minimally invasive treatment option for lumbar disk herniation (LDH). However, studies reporting the efficacy of condoliase in patients aged

Purpose: This study examined the relationship between stem alignment and the cortical bone area around the distal end of the femoral component using three-dimensional computed tomography (3D-CT) images after uncemented total hip arthroplasty (THA). Methods: A total of 59 patients who underwent primary THA using an uncemented short tapered wedge stem from 2019 to 2021 were followed for at least 24 months. Patients were divided into groups based on stem position. Changes in stem position and cross-sectional area of femoral cortical bone at the distal end of the stem were examined using 3D-CT at 12 months and 24 months post-operatively and were compared with pre-operative values. Results: The 12-month post-operative cortical bone area around the stem showed significant differences compared with the pre-operative area in the anterior, posterior, and lateral zone 1. Differences at these same points were noted when comparing the 24-month post-operative area with the pre-operative area. No significant difference was found in the change in the cortical bone area over time among the neutral, flexed, and extended stem groups. In the varus stem group, a significant increase in cortical bone area over time was observed in lateral zone 2. In the valgus stem group, a significant increase in the cortical bone area over time was observed in medial zone 1. Conclusions: Stem alignment may affect periprosthetic cortical bone changes after THA using an uncemented short tapered wedge stem. Cortical bone reaction was revealed laterally to the stem tip in the varus-aligned stem, and medially to the stem tip in the valgus-aligned stem.

Objectives: Locomotive syndrome stage 3 (LS3), which has been established recently, may imply a greater need for care than LS stage 0 (LS0), LS stage 1 (LS1), and LS stage 2 (LS2). The relationship between LS3 and long-term care in Japan is unclear. Therefore, this study aimed to examine this relationship. Methods: A total of 531 patients (314 women and 217 men; mean age, 75 years) who were not classified as requiring long-term care and underwent musculoskeletal examinations in 2012 were grouped according to their LS stage. Group L comprised patients with LS3 and Group N comprised those with LS0, LS1, and LS2. We compared these groups according to their epidemiology results and long-term care requirements from 2013 to 2018. Results: Fifty-nine patients (11.1%) were diagnosed with LS3. Group L comprised more patients (50.8%) who required long-term care than Group N (17.8%) (P

Objectives: We investigated the relationship between the perioperative nutritional status and postoperative walking ability in patients with hip fractures. Methods: We included 246 surgically treated elderly patients with hip fractures who were ambulatory before the injury. Patients were divided into two groups: group A, who were able to walk at discharge, and group B, who were unable to walk at discharge. We pair-matched these two groups according to age, preoperative subdivided walking ability, and fracture site to form groups A′ and B'. The prognostic nutritional index (PNI; PNI = 10 × serum albumin (g/dL) + 0.005 × blood total lymphocyte count (/mm³)) before surgery and 1 day, 1 week, and 2 weeks after surgery and energy intake 1 and 2 weeks after surgery were compared. Results: After adjustments for age, preoperative subdivided walking ability, and fracture site, there were 51 patients in group A' (mean age 84.6 years) and 51 patients in group B' (mean age 84.7 years). In group A'/group B′, PNI was 43.38/42.60 (P = 0.19) before surgery, 33.87/33.31 (P = 0.44) 1 day after surgery, 34.99/32.35 (P = 0.01) 1 week after surgery, and 37.33/35.69 (P = 0.15) 2 weeks after surgery. Energy intake was 1380.8/1203.1 kcal (P = 0.01) 1 week after surgery and 1382.0/1335.6 kcal (P = 0.60) 2 weeks after surgery. Conclusions: PNI and energy intake at 1 week postoperatively were associated with early postoperative nutrition and the recovery of walking ability.

Purpose: Delirium has been reported to cause delayed functional recovery, prolonged hospitalization, future institutionalization, increased mortality, and increased healthcare costs. However, there are no reports on how prognostic nutritional index (PNI), Controlling Nutritional Status (CONUT) score, and geriatric nutritional risk index (GNRI) are related to delirium after total knee arthroplasty (TKA). This study aimed to identify risk factors for post-operative delirium after TKA using various pre-operative nutritional assessments (PNI, CONUT score, and GNRI). Methods: In total, 289 patients who underwent primary TKA between September 2011 and April 2022 in our institute (Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan) were enrolled. Patients were divided into two groups: those who developed post-operative delirium (Group D), and those who did not (Group ND). Pre-operative risk factors, including nutritional indices, for post-operative delirium were evaluated. Results: Group D comprised 16 participants, while Group ND comprised 273 participants. Comparisons between the two groups revealed significant differences in age, PNI, CONUT score, GNRI, and history of cerebrovascular disease. Multiple logistic regression analysis revealed that significant risk factors for delirium after TKA were age, PNI, and history of cerebrovascular disease. A receiver operating characteristic curve indicated that the cutoff values for delirium were 47.4 for PNI (sensitivity, 0.810; specificity, 0.875) and 78.5 years for age (sensitivity, 0.813; specificity, 0.722). Conclusions: Risk factors for post-operative delirium after TKA were PNI 78.5 years, and history of cerebrovascular disease. Patients exceeding these pre-operative cutoff values or with a history of cerebrovascular disease should receive counseling about delirium before surgery.

Background: Adult spinal deformity (ASD) surgery has gained popularity, with significant improvements in patient-reported outcomes. Posterior lumbar interbody fusion with multiple grade II osteotomies (PLIF + MOs) and lateral lumbar interbody fusion (LLIF) have been utilized to correct ASD; however, no studies have compared these methods with regard to the pre- and postoperative changes in length and volume of the spinal canal. This study aimed to investigate the 3-dimensional changes in the anterior vertical column length (AVCL), spinal canal length (SCL), and spinal canal volume (SCV) in patients with ASD after surgery, employing LLIF and PLIF + MOs. Methods: This retrospective study examined 44 patients with ASD who underwent surgery between 2010 and 2021 using two corrective surgical methods, LLIF and PLIF + MOs. Radiographic parameters and clinical outcomes were assessed, and three-dimensional models were created from computed tomography images to analyze changes in AVCL, SCL, and SCV. Results: We compared the effects of LLIF and PLIF + MOs on spinal canal dimensions during ASD surgery. LLIF demonstrated an increase in lumbar segment (L1-S1) AVCL and whole spine (T1-S1) SCL by 6.5 ± 8.0 mm and 13.8 ± 7.6 mm, respectively, compared with PLIF + MOs. However, PLIF + MOs exhibited a reduction in the lengths of the lumbar segment AVCL. Postoperative differences were significant for AVCL (L1-S1), SCL fusion level, and first-standing lumbar lordosis between the groups ( p < 0.0001, 0.002, and 0.016, respectively). LLIF significantly increased the SCV at the fusion level and whole spine T1-S1 by 14.5% and 10.6%, respectively, outperforming PLIF + MOs. Despite changes in dimensions, the postoperative Oswestry disability index scores showed no significant difference between the two groups. Conclusions: Our study suggests that LLIF can increase spinal canal space, lumbar lordosis, and anterior column length in the lumbar spinal segment. Knowledge of these variations may be critical for enhancing surgical outcomes and preventing neurological complications.

Introduction: Previous research has demonstrated that mid- to long-term health-related quality of life following corrective fusion surgery for adult spinal deformity (ASD) can be improved by appropriate revision surgery. In this study, we aim to compare the cost-effectiveness of corrective fusion surgery for ASD with and without unexpected revision surgery 5 years postoperatively. Methods: In total, 79 patients with ASD (mean age, 68.7 years) who underwent corrective fusion surgery between 2013 and 2015 were included in this study. Cost-effectiveness was evaluated based on the cost of obtaining 1 quality-adjusted life year (QALY). Patients were divided into two groups according to the presence or absence of unexpected revision surgery following corrective fusion and were subjected for comparison. Results: As per our study findings, 26 (33%) of the 79 ASD patients underwent unexpected revision surgery during the first 5 years following surgery. Although there was no significant difference in terms of inpatient medical costs at the time of initial surgery for 5 years after surgery between the two groups (no-revision group, revision group; inpatient medical costs at the time of initial surgery: USD 69,854 vs. USD 72,685, P=0.344), the total medical expenses up to 5 years after surgery were found to be higher in the revision group (USD 72,704 vs. USD 104,287, P

Introduction: Condoliase-based chemonucleolysis is a minimally invasive intermediate treatment option between conservative approaches and surgical interventions for lumbar disk herniation (LDH). In this study, the effects of psychological factors on the clinical outcomes of condoliase therapy for LDH were assessed. Methods: This study involved patients with LDH who received condoliase injections over a 1-year follow-up period. Data from the visual analog scale (VAS) scores for leg and back pain, Oswestry Disability Index, and Hospital Anxiety and Depression Scale (HADS), which was utilized for the psychological assessment, were collected. Using magnetic resonance imaging, changes in disk height and degeneration were evaluated. Data were assessed at baseline and 1-month, 3-month, and 1-year follow-ups. Condoliase therapy was considered effective in patients whose VAS score for leg pain improved by 50% at 1 year from baseline and who did not require surgery. The patients were divided into two groups: those who reported effective treatment (Group E) and those who did not (Group I). Between these two groups, comparative analyses were carried out. Results: In this study, a total of 102 patients (70 men; mean age, 43.8±18.2 years) were included. Condoliase therapy was effective in 76 patients (74.5%). Thirty-five patients (34.3%) showed psychological factors (HADS-Anxiety [HADS-A]8 or HADS-Depression [HADS-D]8) preoperatively and had a significantly lower rate of effectiveness than did those without psychological factors. Group I demonstrated significantly higher baseline back pain VAS, HADS, and HADS-D scores when compared with Group E. Logistic regression analysis identified females and the baseline HADS-D score as independent factors that were related to the effectiveness of condoliase therapy. Conclusions: The patients with psychological factors tended to experience residual pain resulting in adverse effects on the clinical outcomes of chemonucleolysis with condoliase.

Abstract Background Intradiscal condoliase injection is an alternative therapeutic option for lumbar disc herniation (LDH). However, it is often associated with disc degeneration. Several in vivo studies have demonstrated the regenerative potential of platelet-rich plasma (PRP) in disc degeneration. Thus, we hypothesized that the intradiscal injection of PRP releasate (PRPr), a soluble releasate isolated from PRP, has the potential to regenerate degenerated intervertebral discs (IVDs) induced by condoliase. This study examined the regenerative effects of PRPr on rabbit IVDs degenerated following condoliase injection. Methods Eleven New Zealand white rabbits were used in this study. Condoliase (12.5 mU/10 μl) was injected into two non-contiguous discs (L2-L3 and L4-L5), and L3-L4 disc was left intact as a non-injection control. Saline (20 μl) or PRPr (20 μl) was randomly injected into L2-L3 and L4-L5 discs 4 weeks after the condoliase injection. Disc height (DH) was radiographically monitored biweekly from the day of condoliase injection to 16 weeks post-injection. Changes in DH were expressed as percentage DH (%DH) normalized to the baseline DH. Sixteen weeks after condoliase injection, all rabbits were euthanized, and subjected to MRI and histological analyses. Results Intradiscal injection of condoliase induced a significant decrease in %DH (L2-L3 and L4-L5) to 52.0% at week 4. However, the %DH began to return to normal after saline injection and reached 76.3% at week 16. In the PRPr group, %DH began to recover to normal after the PRPr injection and was restored to 95.5% at week 16. The MRI-modified Pfirrmann grade of the PRPr group was significantly lower than that of the saline group (P

Introduction: Epidemic preventive management during the coronavirus disease 2019 (COVID-19) pandemic may have negatively impacted perioperative outcomes in patients with traumatic spinal cord injury (SCI). However, little is known about the relationship between epidemic preventive management and delirium after traumatic SCI. Here, we clarified the predictors of delirium after SCI surgery. Methods: We retrospectively analyzed 231 patients (mean age, 66 years) who underwent SCI surgery between 2017 and 2021. Patients were categorized into the delirium and non-delirium groups. Preoperative characteristics and laboratory data related to the occurrence of delirium were assessed. During the study period, we continued early surgical intervention. However, early rehabilitation intervention was not performed in the hospital rehabilitation room from May 2020 due to epidemic preventive management, which involved performing rehabilitation on the bed for 8 days postoperatively. Results: Postoperatively, 33 (14.3%) patients experienced delirium. Univariate analysis showed that age (p

Study Design A retrospective cohort study. Purpose Our aim is to investigate the relationship between degenerative lumbar scoliosis (DLS), and whole-body alignment, including spinopelvic and lower extremity alignments. Overview of Literature DLS is a deformity commonly associated with aging. However, the correlation between whole-body alignment and DLS remains controversial. Methods Adult volunteers aged over 50 years were included in the study after participating in the screening program. Characteristic data and standing radiographic parameters were assessed. A propensity score model was established with adjustments for age and sex after a preliminary analysis, and cases were divided into DLS (Cobb angle >10°) and non-DLS (Cobb angle ≤10°) groups. Results There were significant differences in age, sex, C2 sagittal vertical axis (C2-SVA), C7-SVA, T1 pelvic angle (TPA), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), PI minus LL (PI–LL), knee angle, ankle angle, pelvic shift, C7-center sacral vertical line, L4 tilt, femur-tibia angle, and hip-knee-ankle angle (all p

Study Design Cohort study. Purpose There is currently no published study that focuses on the spinal corrective surgery effects with cranial parameters in adult spinal deformity (ASD) patients. It is an important factor to measure since it plays a critical role in maintaining the line of sight. The objective is to determine the change in cranial parameters using the slope of McGregor’s line (McGS) after ASD surgery after 2 years of follow-up. Overview of Literature A study concluded that cervical spine alignment (C2–C7 lordosis) is strongly affected by thoracic kyphosis (TK). Another study showed that patients with ascending gaze had significantly more thoracolumbar malalignment. Methods This retrospective study includes 295 corrective surgery patients with ASD. Subjects were divided into two groups after propensity age matching analysis: cranial malalignment (McGS 13) and normal cranial alignment (−8≤ McGS ≤13). Lumbar lordosis (LL), pelvic tilt (PT), TK, cervical lordosis (CL), and sagittal vertical axis (SVA) were evaluated between the two groups. Results SVA (95–56 mm) and PT (34°–25°) decreased and LL (19°–41°) increased 2 years after surgery (p

Study Design This is a retrospective study. Purpose This study aimed to investigate the incidence of and risk factors for postoperative shoulder imbalance (PSI) in patients with Lenke type 1. Overview of Literature PSI is a complication resulting in poor self-image and satisfaction in adolescent idiopathic scoliosis (AIS) patients. Methods We examined the data of AIS patients with Lenke type 1 curves who underwent posterior fusion surgery in a retrospective manner. PSI was defined as a 2-year postoperative absolute radiographic shoulder height (RSH) of ≥2 cm. Patients were divided into two groups based on the presence of PSI and the level of their upper instrumented vertebra (UIV) (UIV at T2 or T3 [U-UIV] or UIV below T3 [L-UIV]). The radiographic parameters and clinical outcomes were compared, and the cutoff values of risk factors were identified by multivariate analysis. Results Of 104 patients, 21 (20.2%) had left shoulder elevation PSI. The PSI group had a significantly greater preoperative RSH (−5.1 mm vs. −14.3 mm) and main thoracic (MT) curve correction rate (77.3% vs. 69.1%) than the non-PSI group. The PSI incidence did not differ between the U-UIV and L-UIV groups. Multivariate analysis identified preoperative RSH and the MT curve correction rate as independent risk factors for PSI. The receiver operating characteristic curve analysis identified the preoperative RSH cutoff value as −6.5 mm and MT curve correction rate cutoff value as 76.9%. Conclusions Even in AIS patients with Lenke type 1 curves, the incidence of PSI was relatively high (20.2%). Patients with preoperative lower right shoulder elevation (i.e., RSH >−6.5 mm) had a higher risk of PSI regardless of UIV level when the MT curve showed a higher correction rate (i.e., correction rate >76.9%).

The lack of truly robust analgesics for chronic pain is owed, in part, to the lack of an animal model that reflects the clinical pain state and of a mechanism-based, objective neurological indicator of pain. The present study examined stimulus-evoked brain activation with functional magnetic resonance imaging in male and female cynomolgus macaques following unilateral L7 spinal nerve ligation and the effects of clinical analgesics pregabalin, duloxetine, and morphine on brain activation in these macaques. A modified straight leg raise test was used to assess pain severity in awake animals and to evoke regional brain activation in anesthetized animals. The potential effects of clinical analgesics on both awake pain behavior and regional brain activation were examined. Following spinal nerve ligation, both male and female macaques showed significantly decreased ipsilateral straight leg raise thresholds, suggesting the presence of radicular-like pain. Morphine treatment increased straight leg raise thresholds in both males and females whereas duloxetine and pregabalin did not. In male macaques, the ipsilateral straight leg raise activated contralateral insular and somatosensory cortex (Ins/SII), and thalamus. In female macaques, the ipsilateral leg raise activated cingulate cortex and contralateral insular and somatosensory cortex. Straight leg raises of the contralateral, unligated leg did not evoke brain activation. Morphine reduced activation in all brain regions in both male and female macaques. In males, neither pregabalin nor duloxetine decreased brain activation compared with vehicle treatment. In females, however, pregabalin and duloxetine decreased the activation of cingulate cortex compared with vehicle treatment. The current findings suggest a differential activation of brain areas depending on sex following a peripheral nerve injury. Differential brain activation observed in this study could underlie qualitative sexual dimorphism in clinical chronic pain perception and responses to analgesics. Future pain management approaches for neuropathic pain will need to consider potential sex differences in pain mechanism and treatment efficacy.

Introduction: Although intraoperative spinal neuromonitoring (IONM) is recommended for spine surgeries, there are no guidelines regarding its use in Japan, and its usage is mainly based on the surgeon's preferences. Therefore, this study aimed to provide an overview of the current trends in IONM usage in Japan. Methods: In this web-based survey, expert spine surgeons belonging to the Japanese Society for Spine Surgery and Related Research were asked to respond to a questionnaire regarding IONM management. The questionnaire covered various aspects of IONM usage, including the preferred modality, operation of IONM, details regarding muscle-evoked potential after electrical stimulation of the brain (Br(E)-MsEP), and need for consistent use of IONM in major spine surgeries. Results: Responses were received from 134 of 186 expert spine surgeons (response rate, 72%). Of these, 124 respondents used IONM routinely. Medical staff rarely performed IONM without a medical doctor. Br(E)-MsEP was predominantly used for IONM. One-third of the respondents reported complications, such as bite injuries caused by Br(E)-MsEP. Interestingly, two-thirds of the respondents did not plan responses to alarm points. Intramedullary spinal cord tumor, scoliosis (idiopathic, congenital, or neuromuscular in pediatric), and thoracic ossification of the posterior longitudinal ligament were representative diseases that require IONM. Conclusions: IONM has become an essential tool in Japan, and Br(E)-MsEP is a predominant modality for IONM at present. Although we investigated spine surgeries for which consistent use of IONM is supported, a cost-benefit analysis may be required.

Introduction: Malnutrition could lead to additional medical complications, and the prognostic nutrition index (PNI) is evaluated to assess the nutritional status of patients. However, the midterm postoperative outcomes of malnutrition in patients with adult spinal deformity (ASD) are unclear. This study aims to investigate postoperative midterm spinal alignment and patients' reported outcome measures (PROMs) in malnourished patients with ASD. Methods: This study recruited 303 ASD patients who underwent surgery. Adult patients 50 years old were categorized into the PNI

Study Design Single-center retrospective case series. Purpose We aimed to evaluate the clinical results of revision surgery for a rod fracture using a posterior-only approach and determine the best procedure to prevent refracture in patients with adult spinal deformity (ASD). Overview of Literature ASD affects the thoracolumbar spine and often requires surgical correction. However, surgery for extensive spinal fusion causes rod fracture, a major mechanical complication. Few studies have described the treatment methods for rod fractures. Furthermore, the clinical outcomes of revision surgery for rod fractures in patients with ASD are currently unclear. Methods We retrospectively reviewed the medical records of 404 patients who underwent corrective fusion surgery for ASD with a minimum 2-year follow-up. We studied cases of reoperation for postoperative rod fractures and investigated surgical procedure, intraoperative findings, clinical course, and rod refracture following revision surgery. Results Rod fracture was observed in 88 patients (21.8%). Fifty-three patients (average age, 68.3 years; average blood loss, 502.2 mL [% estimated blood volume=16.4%]; and operation time, 203.3 minutes) who suffered from a rod fracture at an average of 28.3 months after the primary operation underwent reoperation. Surgical invasiveness had no significant differences in total or partial rod replacement; however, the procedures with and without an anterior bone graft significantly differed. The replaced rod refractured at an average of 35.3 months after the revision surgery of five patients. The rod also refractured at a level outside multiple rods in two patients and with traumatic episodes in three patients. Three patients had bone grafts in the anterior column. Conclusions Revision surgery involving a multirod with a posterior-only approach for a rod fracture that occurred after ASD was performed successfully. Bone grafting in the anterior column is unnecessary for patients without massive bone defects.

Abstract No validated systems exist for selecting the upper instrumented vertebra (UIV) for optimal postoperative shoulder balance in Lenke type 2 adolescent idiopathic scoliosis (AIS). This study evaluated a new method for shoulder balance prediction using the modified Shinshu line (MSL) for UIV selection in AIS Lenke type 2 curves. Fifty-five consecutive AIS patients receiving posterior spinal fusion (PSF) for a Lenke type 2 AIS curve were retrospectively analyzed according to several UIV determination models. Shoulder imbalance was judged as absolute radiographic shoulder height ≥ 10 mm at the 2-year observational endpoint. The MSL was the line between the center of the spinous process of C7 and that of the lowest instrumented vertebra. The vertebral body first touched proximally by the MSL was defined as the MSL vertebra (MSLV) and recommended as the UIV. The group with the UIV matching the MSLV had a significantly lower prevalence of shoulder imbalance of 23% (odds ratio 4.08, 95% CI 1.22–13.7, P = 0.02). Setting the MSLV as the UIV in PSF for AIS Lenke type 2 may reduce the prevalence of postoperative shoulder imbalance.

Introduction: Proximal junctional failure (PJF) and rod fracture (RF) are the primary reasons for revision surgery after a long corrective fusion for the adult spinal deformity (ASD). However, many recent studies on ASD are multicenter studies from the US and European racial characteristics may differ from those of Asians. Therefore, the risk factors for revision surgery because of PJF and RF after ASD surgery were evaluated in Japanese patients. Methods: Patients with ASD who underwent corrective surgery from the thoracic vertebrae to the ilium at the authors' institution were reviewed. Demographic, surgical, and radiographic parameters were included in the analysis. Univariate and multivariate regression models were used to analyze the risk factors for PJF and RF. Results: Two hundred and fifty-nine patients were included in the study. A total of 73 patients (28.1%) required revision surgery because of mechanical complications and 15 patients (5.7%) required revision surgery because of PJF on average 380 days after surgery. In PJF cases, body mass index (BMI) and pelvic tilt were significantly higher (p=0.01, p=0.048, respectively). BMI was an independent risk factor for revision owing to PJF (odds ratio [OR], 1.16; p=0.013). A total of 49 patients (18.9%) required revision owing to RF on average 867 days after surgery. Three-column osteotomy (p

Introduction: Corrective fusion for adult scoliosis often requires fusion from the thoracic spine to the lower lumbar spine or pelvis. However, it is often difficult to determine the lowest instrumented vertebrae (LIV), especially in younger patients. The purpose of this study was to summarize the clinical outcomes and revision surgery rates after corrective fusion for adult scoliosis at different LIV levels in patients under 50 years of age. Methods: We retrospectively analyzed 25 patients with adult scoliosis (mean age, 38 years; mean follow-up, 65 months) who underwent corrective fusion from the thoracic spine to L4, L5, or pelvis between 2010 and 2018. Preoperative and at least 2 years' postoperative radiographic parameters, patient-reported outcomes (Scoliosis Research Society-22r [SRS-22r]), mechanical complications, and revision surgery were investigated, and comparisons were made between two groups: the L4 and L5 (L) group (n=14) and the pelvic group (n=11). Results: Both groups showed a significant improvement in the SRS-22r domains of Self-image and Subtotal postoperatively compared with the baseline (P

Abstract Osteoarthritis (OA) is a common disease of joints that is more common in females than in males. It is characterized by severe knee degeneration, damaged cartilage and appearance of osteophytes. Hip geometry and morphometric parameters in the knee joint vary between the sexes and depend on the severity of OA and the presence of osteophytes. Very few studies have assessed this phenomenon; therefore in this study, we assessed the difference in hip geometry and morphometric parameters in the lower limbs of males and females and evaluated the association of the differences with the presence or absence of osteophytes. Three hundred and six knees volunteers (104 male knees and 202 female knees) from the Toei region were included in the study between 2012 and 2018. The parameters measured were from the anteroposterior and lateral views of the hip and anteroposterior view of the knee. The participants were divided into 4 groups based on the assessment for osteophytes: Group 1 had no osteophytes, Group 2 had lateral compartment osteophytes, Group 3 had medial compartment osteophytes, and Group 4 had osteophytes in both compartments. Males had an increased femoral neck-shaft angle, femoral-tibial angle, and plateau angle, and a decreased femoral offset, femoral neck length, fibular-tibial angle, and knee rotation index than females. Group 2 had a greater height of the hip center, the angle between the femoral mechanical axis and the femoral shaft axis, condylar-hip angle, and plateau angle than Group 1. Group 3 showed an increased abductor angle, the angle between the femoral mechanical axis and the femoral shaft axis. Group 4 showed an increased angle between the femoral mechanical axis and the femoral shaft axis, femoral-tibial angle, and a decreased patellar shift index and knee rotation index. The angle between the femoral mechanical axis and the femoral shaft axis, condylar-hip angle, femoral-tibial angle, plateau angle, patellar shift index, and knee rotation index were different in both sexes and may be dependent on the presence or absence of osteophytes.

Study Design Single-center prospective study. Purpose To investigate anterior spinal artery (ASA) status using preoperative selective angiography in patients undergoing surgery for thoracic ossification of the posterior longitudinal ligament (T-OPLL). Overview of Literature Surgery for T-OPLL has a high risk of neurological complications, which might be associated with insufficient spinal cord blood flow. Methods This study prospectively examined nine T-OPLL patients who underwent posterior thoracic decompression with kyphosis correction and instrumented fusion at Hamamatsu University School of Medicine between 2017 and 2019. All underwent preoperative selective angiography to detect and evaluate the Adamkiewicz artery and ASA. Intraoperative neuromonitoring and Doppler ultrasonography were performed to analyze neurological complications and spinal cord blood flow. Results All nine patients showed ASA stenosis in the area of T-OPLL. In all patients, the Adamkiewicz artery was located between T7 and L2 and the area of ASA stenosis corresponded to the level of T-OPLL and greatest spinal cord compression; intraoperative Doppler ultrasonography confirmed the ASA defect at the same spinal level. The number of spinal levels from the Adamkiewicz artery to the most compressive OPLL lesion was greater in the two patients who developed postoperative neurological deficit compared to those who did not (5.5 vs. 2.3, p=0.014). Conclusions This is the first study to report detection of ASA stenosis in patients with T-OPLL. Maintaining spinal cord blood flow is important in these patients to avoid neurological deterioration.

Objectives: To investigate renal function during denosumab therapy using the estimated glomerular filtration rate based on cystatin C (eGFRcys) which is more accurate than creatinine (eGFRcr) for renal function. Methods: Bone mineral densities (BMDs) of lumbar spine and hip regions, eGFRcys, eGFRcr, creatinine clearance (Ccr), and serum total homocysteine (S-Hcy) were measured during 2-year denosumab therapy in 53 women with osteoporosis naïve to anti-osteoporosis drugs (new group) and 64 women who were switched from long-term bisphosphonate treatment to denosumab therapy (switch group). Results: There were no significant differences in age, eGFRcr, Ccr, eGFRcys, and S-Hcy levels at baseline between the groups. BMDs in the lumbar spine, femoral neck, and total hip increased significantly after 2-year denosumab therapy in both groups. eGFRcr decreased in the switch group, and Ccr decreased in both groups; however, eGFRcys and S-Hcy levels did not change significantly in either group. To investigate the causal factors associated with the decrease in eGFRcr and Ccr, multiple regression analysis was performed in all patients. Denosumab initiation within 3 months after fracture and eGFRcr or Ccr at baseline were independent factors for the decrease in eGFRcr or Ccr during the 2-year denosumab therapy. Decline in creatinine-based renal function could be reflected by increased muscle mass during the ongoing recovery from fracture. Conclusions: Renal function was preserved in all patients, including those in the switch group during denosumab therapy. Creatinine-based renal function should be cautiously interpreted during denosumab therapy in patients with recent fractures.

Background: The interaction between knee osteoarthritis and spinal deformity and knee flexion (KF) remains unclear. We aimed to clarify the relationship between KF in the standing position and the severity of spinal deformity and knee osteoarthritis. Methods: We analyzed older volunteers aged over 60 years who participated in the musculoskeletal screening program. The participant’s characteristics and standing radiographic parameters were assessed. After a preliminary analysis, a propensity score-matched model was established with adjustments for age, sex, and body mass index (BMI). Cases were divided into KF (knee angle [KA] ≥10°) and non-KF (KA

Study Design Cross-sectional study. Purpose To investigate the association between vaginal delivery and pelvic parameters and clarify the effect of parity on parameter fluctuations. Overview of Literature During vaginal delivery, the sacroiliac joint widens and the sacrum nutates (nods). However, the association between these pelvic parameters and parity is unknown. Methods As part of a 2016 health screening, 320 female volunteers underwent whole-spine radiographs. Age-matched healthy women were grouped according to the number of vaginal deliveries (0, 1–2, or ≥3). Demographic variables and spinopelvic parameters were compared among the three groups. Results Of the 320 volunteers, 213 were enrolled (mean age, 71.1±7.2 years). The mean number of vaginal deliveries was 2.2. The average pelvic incidence (PI) was 55.6°±11.1° and was significantly higher in the 90 women with three or more vaginal deliveries than in the other two groups (p

Introduction: Assessments of early postoperative bony union after posterior lumbar interbody fusion via computed tomography (CT) have revealed cases in which interbody fixation by bony union resulted in nonfusion due to bone absorption. The apparent bone union state reverted to a nonunion state several months later, exhibiting a so-called “fake union” phenomenon. Additionally, few reports have evaluated the effect of teriparatide on bony union. The present study aimed to evaluate the frequency of change in assessment from fusion to nonfusion in the postoperative follow-up of lumbar interbody fusion, compare the late postoperative bony union rates in groups with or without early postoperative fusion, and examine the effect of postoperative teriparatide in those groups. Methods: Sixty-nine subjects enrolled from multiple hospitals were prospectively evaluated following single-level lumbar interbody fusion. The patients were randomly allocated into treatment with or without weekly postoperative teriparatide. The subjects were then classified as having bony union or nonfusion at 2 months postoperatively, and fusion rates at 6 months were compared. For the evaluation of bony union, blinded radiological examinations were performed via CT. Additional comparisons were made according to teriparatide use. Results: The rate of nonunion at 6 months postoperatively in patients with fusion at 2 months postoperatively was 27.8%. Among subjects with bony union at 2 months postoperatively, the fusion rate at 6 months in those who received teriparatide was 93.3% (p=0.027) versus 57.1% in those who did not. Conclusions: The rate of nonunion at 6 months postoperatively in patients exhibiting union at 2 months after surgery was 27.8%. Postoperative weekly teriparatide treatment significantly reduced the rate of fake union.

Introduction: Kyphotic deformity is common after spinal tumor resection surgery. An adequate field of view is needed to resect the spinal cord tumor, and, in some cases, the facet joint must be removed during laminectomy, and fixation may be performed simultaneously. In this study, we investigated the incidence of postoperative deformity after spinal tumor resection and the factors associated with postoperative deformity. Methods: We retrospectively analyzed patients who underwent thoracic spinal cord tumor resection at a single institution between 2010 and 2017 and were followed up for at least 24 months after surgery. Fifty percent or more of the facet joint was removed during the laminectomy, and fixation was performed simultaneously. Patients were divided into two groups, with and without kyphotic deformity. Patient demographic characteristics (age at surgery and gender), whether they underwent primary surgery or reoperation, tumor level, pathological type, and surgical method were compared. Multiple linear regression analysis was performed to identify independent predictors of kyphotic deformity. Results: Thirty-one patients were found to be eligible. Thirteen patients had intramedullary spinal cord tumors. Laminectomy was performed in 52% (N=16), laminoplasty in 6% (N=2), and laminectomy and/or laminoplasty combined with fusion in 42% (N=13) of the patients. During a mean follow-up period of 66.8 months, 12 (39%) patients had postoperative kyphosis deformities, of which one patient (3%, a 12-year-old girl who underwent combined postoperative radiation therapy) underwent kyphosis correction surgery three years after surgery. The number of laminectomies was independently associated with kyphotic deformity. Conclusions: Although kyphotic deformity after spinal tumor surgery was observed in about 39% of the patients, corrective surgery was rarely required due to the progression of the deformity. The high number of laminectomies is a risk factor for postoperative kyphosis, and prophylactic fixation may be considered in cases of multiple laminectomies.

Abstract Ligamentum flavum hypertrophy (HLF) is the most important component of lumbar spinal canal stenosis (LSCS). Analysis of hypertrophied ligamentum flavum (HLF) samples from patients with LSCS can be an important que. The current study analyzed the surgical samples of HLF samples in patients with LCSC using quantitative and qualitative high performance-liquid chromatography and mass spectrometry. We collected ligamentum flavum (LF) tissue from twelve patients with LSCS and from four patients with lumbar disk herniation (LDH). We defined LF from LSCS patients as HLF and that from LDH patients as non-hypertrophied ligamentum flavum (NHLF). Total lipids were extracted from the LF samples and evaluated for quantity and quality using liquid chromatography and mass spectrometry. The total lipid amount of the HLF group was 3.6 times higher than that of the NHLF group. Phosphatidylcholines (PCs), ceramides (Cers), O-acyl-ω-hydroxy fatty acids (OAHFAs), and triglycerides (TGs) in the HLF group were more than 32 times higher than those of the NHLF group. PC(26:0)+H+, PC(25:0)+H+, and PC(23:0)+H+ increased in all patients in the HLF group compared to the NHLF group. The thickness of the LF correlated significantly with PC(26:0)+H+ in HLF. We identified the enriched specific PCs, Cers, OAHFAs, and TGs in HLF.

Abstract Background Condoliase has been used in Japan to treat patients with lumbar disc herniation by its injection into the nucleus pulposus. The injection of condoliase together with contrast media is prohibited; because there are no data whether contrast media have any effect on condoliase activity. This study aimed to elucidate the effects of contrast media on condoliase activity. Methods Condoliase with chondroitin sulfate (CS) and without CS were mixed with various contrast media (nonionic [iohexol or iotrolan]; ionic [amidotrizoic acid]). (i) The mixtures with CS were incubated at 37°C; (ii) the mixtures without CS were stored at 24°C for 60 min, followed by addition of CS to assess condoliase activity by measuring the amount of N‐acetylhexosamines enzymatically cleaved from CS using Morgan–Elson method. Results (i) In the presence of CS, the ionic contrast media reduced condoliase activity within 10 min in a dose‐dependent manner, and the nonionic contrast media had no effect on condoliase activity for at least 120 min. (ii) In the absence of CS, the ionic contrast media almost completely inactivated condoliase within 15 min, and the nonionic contrast media also reduced condoliase activity; the residual activity was 65% with iotrolan and 35% with iohexol at 60 min. Conclusions The ionic contrast media significantly reduced condoliase activity regardless of presence or absence of CS. Although the nonionic contrast media did not affect condoliase activity in the presence of CS, it reduced activity in the absence of CS. Mixing condoliase with contrast media, especially ionic type contrast media, should be avoided.

Study Design Combination of retrospective and prospective study. Purpose We aimed to compare the clinical outcomes between local fixation surgery and spinopelvic fixation surgery for the treatment of kyphosis secondary to osteoporotic vertebral fractures with spinopelvic malalignment. Overview of Literature The clinical characteristics of patients with rigid kyphosis due to osteoporotic vertebral fracture differ from that of middle-aged patients with vertebral fractures in terms of bone fragility and presence of spinopelvic malalignment. Little is known about the surgical strategies for these deformities, most especially the extent of fusion of vertebra involved. Methods We analyzed 24 patients with vertebral osteotomy at the level of the fracture and spinal fixation without pelvic fixation (local group), and 22 patients with vertebral osteotomy and pelvic fixation (pelvic group). Radiographic parameters, the incidence of proximal junctional kyphosis (PJK), distal junctional kyphosis (DJK), rod fractures, and the Oswestry Disability Index (ODI) were compared between the two groups over a 2-year follow-up period. Results In the pelvic group, postoperative spinopelvic parameters significantly improved, with the improvements maintained. No remarkable changes in spinopelvic parameters were seen in the local group. The mean ODI scores 2 years after surgery were 45.3 and 33.0 in the local and pelvic group, respectively (p-value

Introduction: Chronic low back pain (CLBP) is a leading cause of disability, yet there is limited high-quality evidence to identify the most suitable pharmacological therapy. The purpose of this Japanese nationwide, multicenter, prospective study was to compare the effectiveness of four representative drug therapies―acetaminophen, celecoxib, loxoprofen, and a tramadol and acetaminophen (T+A) combination drug―to establish evidence for a drug of choice for CLBP. Methods: Patients with CLBP (N=471) received one of the four treatments and were evaluated, prospectively and comprehensively, once every month for six months using a visual analog scale (VAS) for LBP, the Japanese Orthopedic Association (JOA) score, the JOA Back Pain Evaluation Questionnaire (JOABPEQ), the Roland-Morris Disability Questionnaire (RDQ), the EuroQol five-dimensions three-levels (EQ-5D-3L), and the Short Form-8 item health survey (SF-8). We conducted multivariable linear regression analyses of the four drugs at 1 and 6 months after drug allocation. Differences with P

Abstract Ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. The bridging of ossified lesions to the vertebral body gradually increases, thereby decreasing the mobility of the cervical spine; thus, cervical spine function may decrease over time. However, cervical spine function in patients with cervical OPLL has not been evaluated in large prospective studies. Therefore, we conducted a prospective multicenter study to clarify whether ossification spread can influence cervical spine function and quality of life (QOL) in patients with cervical OPLL. In total, 238 patients (162 men, 76 women; mean age, 63.9 years) were enrolled from 16 institutions. Each patient underwent whole spine computed tomography and was evaluated for cervical spine function and QOL using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). In the multivariate regression analysis, a higher neck VAS score and a larger number of bridge formations of OPLL in the whole spine were significant predictors of adverse outcomes related to cervical spine function. This is the first prospective multicenter study to reveal the impact of ossification spread on cervical spine function. These findings are important to understand the natural course of OPLL and can serve as controls when evaluating postoperative cervical spine function.

Background: Since 1929, only 171 epidural hemangioma cases have been reported. We report five epidural hemangiomas and review cases reported over the past decade in terms of radiological features and clinical findings. Methods: Among patients operated on for spinal tumors at our hospital between 2009 and 2020, five had epidural hemangiomas. We retrospectively examined patient records and images and reviewed relevant English literature in PubMed from 2009 to 2019. Eighty-seven epidural hemangioma cases were reported in the last 10 years. Results: Among 87 cases, the average age was 49.58 years; 43 and 44 cases were male and female, respectively. The most common lesion level was thoracic (59.8%), while common symptoms were back pain (42.5%); numbness, hypoesthesia, or anesthesia (37.9%); paraparesis (34.5%); and radicular pain (20.7%). On magnetic resonance imaging (MRI), 77.1% showed hypo-isointensity on T1-weighted image (WI), hyperintensity on T2WI, and homogenous enhanced patterns with contrast. Total resection was performed in most cases, with good clinical outcomes. Preoperative embolization was performed in four cases, with good surgical outcomes. The median follow-up duration of postoperative MRI was 16 months, and no case had recurrence. Conclusions: Epidural hemangiomas are extremely rare and may be difficult to diagnose preoperatively. They should be considered if a dumbbell-shaped or epidural hypervascular lesion is noted. The treatment of choice for epidural hemangioma is total resection, with most cases having good clinical outcomes. Preoperative embolization may be useful for reducing bleeding. Although there were almost no recurrences after resection, careful follow-up for longer periods is required.

Solitary fibrous tumors are rare mesenchymal neoplasms with highly recurrence rates after intratumor resection. We report 2 cases of solitary fibrous tumors treated with combination therapy with embolization and en bloc laminectomy using thread saw. To the best of our knowledge, this is the first such report. In the 2 cases, the hypervascular tumors were located in the spinal process and infiltrating the multifidus. Preoperative embolization was useful for decreasing intraoperative bleeding, and using thread saw was an ideal technique for deciding the cut surface height of the pedicle to achieve gross total resection.

Study Design Large cohort study of volunteers. Purpose The purpose of this study was to investigate the relationship between the severity of knee osteoarthritis, assessed using the Kellgren-Lawrence (KL) grading scale, and spinopelvic sagittal alignment in older adult volunteers. Overview of Literature The relationship between spinopelvic alignment in the sagittal plane and knee osteoarthritis in the coronal plane is unclear. Methods Volunteers over 50 years of age underwent radiographic analysis. Radiographic parameters including pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), thoracic kyphosis, and sagittal vertical axis (SVA) were measured. The the three Scoliosis Research Society-Schwab sagittal modifiers (PT, SVA, PI–LL) were categorized and the KL grade was assessed. Differences in spinopelvic parameters and Oswestry Disability Index (ODI) scores among KL grades were evaluated. Results A total of 396 volunteers (160 men, 236 women; mean age, 74.4 years) were analyzed. PI–LL and PT in KL4 were significantly higher compared to that in the other KL grades. However, there were no significant group differences in SVA. In women, but not in men, higher frequencies of the worst modifier grade (++) were observed for PI–LL and PT in the KL3 and KL4 groups compared to those for the other KL grades. In women, the ODI score in KL4 was worse compared to that in the other KL grades. Conclusions Individuals over 50 years of age with severe knee osteoarthritis had poor lumbo-pelvic sagittal alignment. Moreover, the progression severity of knee osteoarthritis had more impact onstronger relationship with lumbo-pelvic malalignment and disability-related low back pain in women than in men.

Introduction: Falling is an age-related problem that increases with age. Compared with younger people, elderly people possess increased risk factors for falls, and falling among the elderly is associated with increased mortality. Risk factors for falls have been reported in elderly outpatients; however, whether sagittal spinal posture affect the risk of falls in community residents remains unclear. Therefore, we aimed to investigate the influence of sagittal spinal posture on the risk of falls in elderly community-dwelling people using spino-plevic sagittal parameters in a retrospective longitudinal study. Methods: A total of 463 volunteers (96 men and 367 women; mean age, 72.8 years) who underwent a routine physical checkup were evaluated. Baseline whole spine and lower limb radiography, physical tests, bone mineral density (BMD), number of medications and comorbidities, patient-reported outcomes (PROs), and a history of falls in the previous four years period were examined. Results: Univariate analysis revealed older age, lower height and weight, higher prevalence of vertebral fractures, higher number of medications, poor physical test scores including one-leg standing test and prone trunk extension, poor PROs, a higher sagittal vertical axis, and higher pelvic tilt (PT) as factors significantly associated with the risk of falls, and multivariate analysis revealed a higher sagittal vertical axis [odds ratio (OR), 1.08; 95% confidence interval (CI), 1.002-1.013; P = 0.02] and locomotive syndrome assessed using the 25-Question Geriatric Locomotive Function Scale score (OR, 1.028; 95% CI, 1.004-1.053; P = 0.03) to be associated with the risk of falls, independent of other factors in the univariate analysis. Conclusions: The sagittal vertical axis was an independent risk factor for falls, and the prevalence of vertebral fractures and prone truck extension correlated with the sagittal vertical axis. Prospective and intervention studies are needed to prevent future falls in elderly community volunteers with a higher sagittal vertical axis.

Introduction: Chronic low back pain (CLBP) is a major health burden worldwide and requires patient satisfaction with treatment. Consultation length can be an important factor in patient satisfaction, but few studies have investigated the impact of consultation length on satisfaction in patients with CLBP. This study tried to elucidate the impact of consultation length on clinical outcomes in patients with CLBP. Methods: This study is part of an analysis using the database of the nationwide, multicenter cohort for CLBP performed by the Project Committee of the Japanese Society for Spine Surgery and Related Research. A total of 427 patients aged 20-85 years (median age, 73.0 years; female, 58.6%) with CLBP were prospectively followed-up monthly for 6 months. Multivariable nonlinear regression analyses were performed to assess the effect of consultation length on outcome measures including subjective satisfaction score, EuroQol 5-dimension, Japanese Orthopaedic Association (JOA) score, Roland-Morris Disability Questionnaire, JOA Back Pain Evaluation Questionnaire, visual analog scale (VAS) and Medical Outcome Survey short-form 8-item health survey that evaluated at the next phase. Furthermore, we assessed whether the effect of consultation length on patient satisfaction was modified by the baseline Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP) score for patient and physician versions. Results: VAS for CLBP was the only score that correlated significantly with consultation length (P = 0.018). Satisfaction score showed a significant positive correlation with consultation length in patients with the highest baseline BS-POP scores (P < 0.2). Moreover, consultation lengths more than 7.6 min and 15.1 min offered increase of satisfaction if patients show the highest BS-POP scores on patient and physician versions, respectively. Conclusions: These findings suggest that a sufficiently long consultation is an important factor for subjective satisfaction in the patients with CLBP, particularly in patients with psychological problems.

Study Design Retrospective cohort study. Purpose This study aimed to investigate how participation in sporting activity affects patient-reported outcome (PRO), including Neck Disability Index (NDI), in males and females. Overview of Literature Previously, our study reported that factors with a negative influence on the NDI in females were a lack of sporting activities. However, it was still unclear why it affected poor scores of NDI. Methods The subjects were 473 volunteers. They were divided into two groups (activity and non-activity) according to participation or non-participation in sporting activities using a self-filled questionnaire. The evaluation items were height, weight, grip strength, bone density, Hospital Anxiety and Depression Scale (HADS) score, standing radiographic parameters, PRO (evaluated by EuroQol-5 dimension [EQ-5D], Oswestry Disability Index [ODI]), and NDI. Results There were 101 males in the non-activity group and 69 in the activity group and 178 females in the non-activity group and 125 in the activity group. For the males, the evaluation items with significant influence were cervical lordosis (non-activity group:activity group, 17°:22°) and T1 slope minus cervical lordosis (10°:6°, p

Study Design Cross-sectional cohort study. Purpose This study aimed to investigate the relationship between hypertension and spino-pelvic sagittal alignment in middle-aged and elderly individuals. Overview of Literature Positive global sagittal alignment is associated with poor health-related quality of life. Hypertension is associated with tissue microcirculation disorders of the skeletal muscle. We hypothesized that hypertension may be involved in positive global sagittal alignment. Methods In this institutional review board-approved study, 655 participants (262 men and 393 women; mean age, 72.9 years; range, 50–92 years) who underwent musculoskeletal screening in Toei town, Aichi, Japan were included. Whole spine and pelvic radiographs were taken, and radiographic parameters (thoracic kyphosis, lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and sagittal vertical axis [SVA]) were measured using an image-analysis software. Hypertension was assessed using the standard criteria. The study participants were divided into three subgroups as per age (50–64 years, 65–74 years, and ≥75 years). We examined the differences in the radiographic parameters of those with and without hypertension in each age subgroup. Results In each age subgroup, there was no significant difference in the age and sex of those with and without hypertension. SVA was significantly shifted forward in the hypertension group than in the non-hypertension group in those aged 50–64 years old (32.4 mm vs. 16.0 mm, p=0.018) and in those aged 65–74 years old (42.7 mm vs. 30.6 mm, p=0.012). There was no significant difference between the hypertension and non-hypertension groups in terms of the alignment of the lumbar and thoracic spine in all the subgroups. In multivariate analysis, hypertension was a significant independent factor of forward-shifted SVA (standardized beta 0.093, p=0.015). Conclusions This study showed that hypertension was associated with forward-shifted global sagittal alignment.

The role of endogenous cannabinoids in neuropathic pain has been actively studied, among which 2-arachidonoyl glycerol (2-AG) has received the most attention. However, owing to its chemical properties, direct detection of 2-AG distribution in tissues is difficult. Moreover, although desorption electrospray ionization mass spectrometry imaging (DESI-MSI) has enabled the detection of 2-AG, its distribution in the brain and spinal cord of neuropathic pain models has not been reported. In this study, the expression and distribution of 2-AG in the brain and spinal cord of a spare nerve injury (SNI) mice model of neuropathic pain was examined using DESI-MSI. The brain and lumbar spinal cord were collected and analyzed on days 3, 7, and 21 after treatment. On days 3 and 7 after treatment, 2-AG expression in the SNI model was decreased in the hypothalamus, midbrain, and especially in the periaqueductal gray (PAG) region but increased in the lumbar spinal cord. On day 21, the SNI model showed decreased 2-AG expression in the hypothalamus, but the difference from the control was not significant. Furthermore, there were no differences in 2-AG expression between the lumbar spinal cord, midbrain, or PAG. These data suggest that 2-AG might be involved in pain control.

Traumatic spinal cord injury (SCI) induces various complex pathological processes that cause physical impairment and psychological devastation. The two phases of SCI are primary mechanical damage (the immediate result of trauma) and secondary injury (which occurs over a period of minutes to weeks). After the mechanical impact, vascular disruption, inflammation, demyelination, neuronal cell death, and glial scar formation occur during the acute phase. This sequence of events impedes nerve regeneration. In the nervous system, various extracellular secretory factors such as neurotrophic factors, growth factors, and cytokines are involved in these events. In the vascular system, the blood-spinal cord barrier (BSCB) is damaged, allowing immune cells to infiltrate the parenchyma. Later, endogenous angiogenesis is promoted during the subacute phase. In this review, we describe the roles of secretory factors in the nervous and vascular systems following traumatic SCI, and discuss the outcomes of their therapeutic application in traumatic SCI.

Fibronectin and leucine-rich transmembrane (FLRT) proteins are necessary for various developmental processes and in pathological conditions. FLRT2 acts as a homophilic cell adhesion molecule, a heterophilic repulsive ligand of Unc5/Netrin receptors, and a synaptogenic molecule; the last feature is mediated by binding to latrophilins. Although the function of FLRT2 in regulating cortical migration at the late gestation stage has been analyzed, little is known about the expression pattern of FLRT2 during postnatal central nervous system (CNS) development. In this study, we used Flrt2-LacZ knock-in (KI) mice to analyze FLRT2 expression during CNS development. At the early postnatal stage, FLRT2 expression was largely restricted to several regions of the striatum and deep layers of the cerebral cortex. In adulthood, FLRT2 expression was more prominent in the cerebral cortex, hippocampus, piriform cortex (PIR), nucleus of the lateral olfactory tract (NLOT), and ventral medial nucleus (VM) of the thalamus, but lower in the striatum. Notably, in the hippocampus, FLRT2 expression was confined to the CA1 region and partly localized on pre- and postsynapses whereas only few expression was observed in CA3 and dentate gyrus (DG). Finally, we observed temporally limited FLRT2 upregulation in reactive astrocytes around lesion sites 7 days after thoracic spinal cord injury. These dynamic changes in FLRT2 expression may enable multiple FLRT2 functions, including cell adhesion, repulsion, and synapse formation in different regions during CNS development and after spinal cord injury.

Introduction: There is currently a lack of translatable, preclinical models of low back pain (LBP). Chymopapain, a proteolytic enzyme used to treat lumbar intervertebral disc (IVD) herniation, could induce discogenic LBP. The current study developed a behavioral model of discogenic LBP in nonhuman primates. Significant brain activation is observed in clinical LBP. Thus, the current study also sought to define brain activation over time in a macaque with discogenic LBP. Methods: Responses to pressure applied to the back at L4/L5 were measured in eight adult male Macaca fasciculata using a pressure algometer. The nucleus pulpous of the IVD between L4 and L5 was aspirated and chymopapain (1 mg/mL) was injected under fluoroscopic guidance (n = 2). In two macaques, the nucleus pulpous was only aspirated. Brain activation in response to pressure applied to the lower back was assessed using a 3.0T magnetic resonance imaging scanner in four macaques before and 1, 3, 9, and 14 days after treatment. Results: The mean (±SD) response pressure before treatment was 1.4 ± 0.1 kg. One day after chymopapain treatment, the response pressure decreased to 0.6 ± 0.05 kg (P < 0.01), suggestive of pressure hypersensitivity. Over time, the pressure thresholds following chymopapain treatment gradually returned to normal. Following aspiration only, the response pressure was 1.4 ± 0.05 kg, which was not significantly different from the uninjured controls. There was activation of the secondary somatosensory cortex and insular cortex one and three days after chymopapain treatment; there was no activation following aspiration only. Conclusions: Enzymatic treatment of the nucleus pulpous leads to acute LBP and pressure-evoked activation in pain-related brain areas. The current model of discogenic LBP parallels clinical LBP and could be used to further elaborate the mechanism of acute LBP.