藤田 順之

Loss of vascular endothelial growth factor (VEGF) signaling profoundly impairs vascular growth during development. In contrast, once established in adulthood, blood vessels become largely quiescent and less dependent on VEGF signaling, providing the rationale for the clinical use of VEGF inhibitors to selectively target tumor angiogenesis. In this study, blood vessels in the epiphysis-the ends of long bones-retained an unexpected degree of plasticity in adult and even aged mice. With tamoxifen-induced, endothelium-specific deletion of Vegf receptor (Vegfr)-2, the principal mediator of Vegf signaling, marked vascular regression was found in the epiphysis, with growth plate cartilage expansion after epiphyseal ischemia. Consistently, local bone strength was significantly reduced with endothelial Vegfr2 depletion in adult mice. With epiphyseal vascular regression, bone mineral density loss was exacerbated in an ovariectomy-induced mouse model of osteoporosis. Collectively, these findings advance the understanding of angiogenic-osteogenic coupling in adulthood and provide a mechanistic framework for the vulnerability of the femoral head and neck to fractures in the elderly.

AIM: Both locomotive syndrome and dysphagia are important health concerns in older patients with degenerative cervical myelopathy (DCM). This study evaluated postoperative changes in locomotive syndrome stage and dysphagia risk and examined whether improvement in locomotive syndrome is associated with dysphagia status in older patients with DCM. METHODS: We retrospectively reviewed patients aged ≥ 65 years who underwent posterior subaxial cervical surgery for DCM. Patient-reported outcomes were assessed preoperatively and at 6 months and 1 year postoperatively using the 25-question Geriatric Locomotive Function Scale and 10-item Eating Assessment Tool. Locomotive syndrome stage and dysphagia status, defined as an Eating Assessment Tool score ≥ 3, were compared over time and according to improvement in locomotive syndrome stage at 1 year. RESULTS: Among 150 patients, locomotive syndrome stage improved significantly at 6 months and 1 year after surgery, with 35 patients (23.3%) improving by 1 year. Conversely, dysphagia prevalence increased over time and was significantly higher at 1 year; new-onset dysphagia occurred in 28 patients (18.7%). Changes in dysphagia status differed significantly between patients with and without improvement in locomotive syndrome stage, with greater deterioration observed in patients without improvement (p = 0.009). A multivariable logistic regression analysis demonstrated a significant association between improvement in dysphagia status and improvement in locomotive syndrome stage. CONCLUSIONS: In older patients with DCM, posterior subaxial cervical surgery was associated with modest improvement in locomotive syndrome stage but increased dysphagia risk. Persistent postoperative locomotive impairment may identify patients requiring careful swallowing assessment.

INTRODUCTION: Although follow-up is recommended for 2 years after lumbar spinal stenosis (LSS) surgery, some patients fail to complete all follow-up visits. In recent years, the treatment burden on older adults has attracted increasing attention, with particular emphasis on outpatient visits. Thus, we aimed to clarify the clinical characteristics of older adults who discontinued postoperative follow-up between 1 and 2 years after LSS surgery. METHODS: This retrospective study included consecutive patients aged ≥65 years who had undergone surgery for LSS at a single center between April 2020 and June 2023. At follow-up assessments scheduled 1 and 2 years after surgery, patients completed the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and the Zurich Claudication Questionnaire (ZCQ). The preoperative and 1-year postoperative JOABPEQ and ZCQ scores were statistically compared between patients who did and did not complete follow-up and were adjusted using analysis of covariance or the Poisson regression model. RESULTS: Among the 330 patients who attended the 1-year follow-up visit, 252 (76.4%) attended the 2-year visit, whereas the remaining 78 (23.6%) did not. Patients who did not complete follow-up exhibited significantly higher rates of dyslipidemia (p=0.022), cardiovascular disease (p=0.005), and frailty (p=0.014), and a lower prevalence of spondylolisthesis (p<0.001) and fusion surgery (p<0.001), than those who completed the follow-up. Furthermore, patients who did not complete follow-up had worse scores in the psychological disorder domain of the JOABPEQ both preoperatively and at 1 year, and worse 1-year scores across all ZCQ domains than those who completed the follow-up. CONCLUSIONS: Several factors were associated with the likelihood of discontinuing postoperative follow-up among older adults with LSS, and their postoperative outcomes were poorer. Therefore, when analyzing data from older adults with LSS at 2 years postoperatively, considering the characteristics of patients who discontinued follow-up is essential.

BACKGROUND: Carpal tunnel syndrome (CTS) occurs more frequently in women than in men; however, the anatomical basis for this sex difference remains unclear. Conventional two-dimensional assessments, such as cross-sectional area (CSA) measurements, are limited to single slices and may not accurately represent whole-tunnel morphology. This study aimed to quantify the three-dimensional volumetric characteristics of the median nerve and carpal tunnel using MRI in healthy adults and to investigate sex-related anatomical differences. METHODS: Seventy-nine healthy adults (36 men and 43 women) underwent three-dimensional wrist MRI, and median nerve volume (MNV) and carpal tunnel volume (CTV) were quantified. The volumetric nerve-to-tunnel ratio (MNV/CTV) was calculated and compared between sexes. For comparison, CSA measurements were obtained at the pisiform and hamate levels. Sex-related differences and the influence of potential confounding factors were evaluated. RESULTS: Men had significantly larger MNV and CTV than women. In contrast, the MNV/CTV ratio was significantly higher in women overall. Level-specific analyses showed a significant sex difference in MNV/CTV at the hamate level but not at the pisiform level. After adjustment for age, body mass index (BMI), and occupational workload, sex remained independently associated with MNV/CTV. Strong correlations were observed between three-dimensional volumetric measurements and CSA measurements of the median nerve. CONCLUSIONS: Three-dimensional MRI identified sex-related differences in relative median nerve occupancy within the carpal tunnel in healthy adults. These findings suggest that volumetric assessment provides complementary anatomical insight beyond conventional CSA measurements and may partly contribute to understanding the higher prevalence of CTS in women.

INTRODUCTION: The Japanese Society for Spine Surgery and Related Research (JSSR) developed a national web-based registry system, integrating it with the Japanese Orthopaedic Association National Registry (JOANR/JSSR-DB) to systematically collect data on spinal and spinal cord surgeries and complications. This study aimed to report on the establishment of JOANR/JSSR-DB, and evaluate the epidemiology of spinal and spinal cord surgery in Japan, in addition to the frequency and characteristics of perioperative complications, on the basis of data from JOANR/JSSR-DB 2022. METHODS: This registry-based study analyzed prospectively collected data in all patients who underwent spinal surgery at JSSR-certified institutions between April 1, 2022 and March 31, 2023. A total of 158,263 cases (89,358 men and 68,905 women; mean age 66.6 years) from 1,032 facilities were included. Data included demographics, diagnoses, surgical procedures, use of intraoperative supportive technologies, intraoperative and 30-day postoperative complications, and systemic complications. RESULTS: Of the total patients, 143,085 (90.4%) underwent initial surgery, 3,712 (2.3%) staged surgery, and 11,301 (7.1%) reoperation/additional surgery. The most prevalent diagnoses were lumbar spinal canal stenosis (51,472, 32.5%), lumbar disc herniation (26,256, 16.6%), and cervical spondylotic myelopathy (15,394, 9.7%). The most common surgical procedures were posterior lumbar interbody fusion (10,910, 6.9%), posterior spinal fusion (10,826, 6.8%), and balloon kyphoplasty (8,274, 5.2%). The frequencies of intraoperative, postoperative, and systemic complications were 2.6% (4,107 patients), 2.7% (4,316 patients), and 1.8% (2,782 patients), respectively. Overall, the complication frequency was 6.5% (10,313 patients). CONCLUSIONS: A comprehensive spine and spinal cord surgery registry was established in Japan, and a comprehensive study was conducted on diseases, surgeries, and complications related to spinal surgeries performed in 2022 in Japan. Ongoing registry-based studies are expected to enhance evidence-based practices, reduce complications, and maintain high medical care standards. LEVEL OF EVIDENCE: 4.