Comparison of Gender Diversity Among Spine Surgeons in the Japanese Society for Spine Surgery and Related Research and the Neurospinal Society of Japan: A Descriptive Study Through Secondary Analysis of Aggregated Data.

STUDY DESIGN: This was a descriptive study through secondary analysis of aggregated data. PURPOSE: This study aimed to describe changes in women's membership in the Japanese Society for Spine Surgery and Related Research (JSSR) for orthopedic surgery and the Neurospinal Society of Japan (NSJ) for neurosurgery over the past decade and make predictions for the future. OVERVIEW OF LITERATURE: Although the ratio of women physicians in the field of spine surgery is known to be low worldwide, there is a lack of detailed surveys in Japan. METHODS: We sent emails to the JSSR and NSJ secretariats to verify membership information (gender and age) from 2013 to 2022. Using ordinary least squares, we projected the years it would take for the JSSR and NSJ to achieve a gender diversity ratio of 30%. RESULTS: In 2013, the percentage of women in JSSR and NSJ was 2.3% and 2.7%, respectively. However, after 2018, the percentage of women in NSJ will be higher than in JSSR, rising to 2.7% in JSSR and 4.7% in NSJ by 2022. It would require 101 years for the NSJ and more than 1,000 years for the JSSR to realize 30% gender diversity. CONCLUSIONS: JSSR and NSJ have low percentages of women. Improving gender diversity is an important issue for both societies, and they may collaborate on finding a good solution. Both the JSSR and NSJ societies need to actively address gender diversity and become more attractively represented in society for the next generation of spine surgeons.

Hereditary Anatomical Risk Factors for Anterior Cruciate Ligament Injuries.

INTRODUCTION:  Genetic and anatomical factors have been reported as risk factors for anterior cruciate ligament (ACL) injuries. This study aimed to investigate anatomical characteristics in family members sustaining ACL injuries, compared with age- and sex-matched patients with simple meniscus injuries. MATERIALS AND METHODS:  Medical records of 1548 patients who underwent ACL reconstruction were reviewed. Cases of ACL injury occurring in first-degree relatives were selected. Forty-one patients from 20 families were included in the study (F-ACL group). Fifty patients with meniscus injuries were included as controls. Anatomical factors comprising posterior-inferior tibial slope (PITS), notch width index (NWI), notch angle (NA), and intercondylar notch roof inclination angle (RA) were compared between groups. The correlation of these anatomical factors between parent and child or siblings was also investigated. RESULTS:  The 41 patients (20 families) consisted of 12 parent-child pairs and 29 siblings (13 pairs and one trio). Injuries occurred during playing the same sport in 11 families (55%). PITS was significantly steeper in the F-ACL group (9.9 vs. 7.8 degrees). NWI and NA were significantly smaller in the F-ACL group (0.262 vs. 0.278 and 50.5 vs. 58.8 degrees). RA was significantly greater in the F-ACL group (130 vs. 126.9 degrees). A positive correlation in NA (r = 0.677) and a weak correlation in NWI and RA were observed between family members. CONCLUSIONS:  Common anatomical risk factors of ACL injury exist within families, including intercondylar notch stenosis and steep posterior tibial slope. The findings suggest the potential for developing effective ACL injury prevention programs targeting these risk factors.

Impacts of Segond Fractures on Anterior Cruciate Ligament Reconstruction Outcomes.

INTRODUCTION: Segond fractures, characterized by avulsion injuries at the lateral tibial condyle's anterolateral structure (ALS) attachment, often coincide with anterior cruciate ligament (ACL) injuries, potentially leading to knee instability. However, the influence of Segond fractures on knee stability after ACL reconstruction remains uncertain. Despite documented ALS reconstructions, there is a lack of consensus regarding the assessment of ALS failure and the criteria for surgical interventions. This study aimed to determine if Segond fracture presence impacts ACL reconstruction outcomes, utilizing patient-reported subjective assessments and healthcare providers' objective evaluations. MATERIALS AND METHODS: This retrospective study encompassed 639 patients (328 males, 311 females; mean age 26.9 years) who underwent ACL reconstruction, with a follow-up of at least one year. Subjects were divided into two groups: Segond fractures diagnosed through radiographic findings (Group S+, n = 17) and no Segond fractures (Group S-, n = 622). Clinical evaluation included the 36-item Short Form Survey (SF-36), Lysholm score, visual analog scale (VAS) for knee pain, knee injury and osteoarthritis outcome score (KOOS), and knee instability assessment via Telos SE (Telos Japan, Tokyo, Japan). Statistical comparisons were performed between the two groups. RESULTS: At the final follow-up, all SF-36 subscales improved in all eight subscales compared to before surgery, reaching national standard scores; no significant inter-group differences were evident. Lysholm scores were 93.0 ± 12.1 (Group S+) and 91.7 ± 10.9 (Group S-) (P = 0.62), VAS for knee pain was 10.0 ± 18.0 (Group S+) and 11.9 ± 16.9 (Group S-) (P = 0.62), total KOOS was 89.0 ± 17.4 (Group S+) and 90.7 ± 9.9 (Group S-) (P = 0.39), and anterior tibial translation differences were 2.8 ± 3.0 mm (Group S+) and 2.7 ± 2.9 mm (Group S-) (P = 0.73). All these values represent postoperative measurements. No significant discrepancies existed between groups across evaluation methods. CONCLUSIONS: This study's results suggest that Segond fractures have minimal impact on clinical ACL reconstruction outcomes, as assessed through both patient-reported subjective evaluations and objective healthcare provider evaluations. Segond fractures' significance in postoperative outcomes questions the necessity of ALS reconstruction.

Impact of Skeletal Muscle Mass on Physical Function and Locomotive Syndrome of Pre- and Postoperative Adult Spinal Deformity.

Background: The purpose of this study is to identify the relationship between locomotive syndrome (LS) status, physical performance and limb and trunk skeletal muscle mass before and after surgery in adult spinal surgery (ASD) patients. Methods: A retrospective observational investigation of 63 consecutive patients with ASD who underwent spinal surgery was conducted. The total skeletal muscle mass of the arms and legs was considered a measure of the total appendicular skeletal muscle mass measured with whole-body dual-energy X-ray absorptiometry. All data pertaining to the physical performance tests and LS were collected preoperatively with follow-up one year postoperatively. Results: Gait speed, the one-leg standing test and the stand-up test were significantly improved one year after surgery compared to preoperative measurements. The lower extremity skeletal muscle mass predominantly influences physical function improvement including gait stride, one-leg standing and the stand-up test after ASD surgery. Conclusions: This study is the first to show that assessing lower extremity muscles prior to ASD surgery is useful in predicting postoperative recovery.

Pivotal role of IL-8 derived from the interaction between osteosarcoma and tumor-associated macrophages in osteosarcoma growth and metastasis via the FAK pathway.

The prognosis of osteosarcoma (OS) has remained stagnant over the past two decades, requiring the exploration of new therapeutic targets. Cytokines, arising from tumor-associated macrophages (TAMs), a major component of the tumor microenvironment (TME), have garnered attention owing to their impact on tumor growth, invasion, metastasis, and resistance to chemotherapy. Nonetheless, the precise functional role of TAMs in OS progression requires further investigation. In this study, we investigated the interaction between OS and TAMs, as well as the contribution of TAM-produced cytokines to OS advancement. TAMs were observed to be more prevalent in lung metastases compared with that in primary tumors, suggesting their potential support for OS progression. To simulate the TME, OS and TAMs were co-cultured, and the cytokines resulting from this co-culture could stimulate OS proliferation, migration, and invasion. A detailed investigation of cytokines in the co-culture conditioned medium (CM) revealed a substantial increase in IL-8, establishing it as a pivotal cytokine in the process of enhancing OS proliferation, migration, and invasion through the focal adhesion kinase (FAK) pathway. In an in vivo model, co-culture CM promoted OS proliferation and lung metastasis, effects that were mitigated by anti-IL-8 antibodies. Collectively, IL-8, generated within the TME formed by OS and TAMs, accelerates OS proliferation and metastasis via the FAK pathway, thereby positioning IL-8 as a potential novel therapeutic target in OS.

Bilateral Patellofemoral Ligament Reconstruction for Patellar Instability in Ehlers-Danlos Syndrome: A Case Report.

CASE: We report the case of an 11-year-old boy with Ehlers-Danlos syndrome (EDC) who exhibited simultaneous medial and lateral patellar instability. The patient presented with a medial patellar dislocation, and subsequently, the patella became very unstable both medially and laterally. Despite distal realignment, the patellar instability was so significant that he underwent simultaneous reconstruction of the medial and lateral patellofemoral ligament using the semitendinosus tendon, with a good result. CONCLUSION: Simultaneous reconstruction of the medial and lateral patellofemoral ligament is an effective method in cases of extreme patellar instability, such as the EDS case.

Case Report: Angiomatoid fibrous histiocytoma in the hand: a rare clinical presentation and diagnostic challenge.

Angiomatoid fibrous histiocytoma (AFH) is a rare tumor of mesenchymal origin occurring in young adults. Based on its clinical course, it is said to have an intermediate potential. We present a case of a 59-year-old woman with AFH in the hand that was difficult to diagnose. A benign soft tissue tumor was suspected on magnetic resonance imaging, and its size and open biopsy suggested nodular fasciitis or inflammatory myofibroblastic tumor. A diagnosis of AFH was eventually made based on the analysis of the resected specimens. The characteristic findings of histopathology and immunohistochemistry in this case were relatively poor, so fluorescence in situ hybridization contributed to making the correct diagnosis. Considering its prognosis, careful follow-up was decided upon without additional surgery. Our case is a challenging one because of its atypical presentation and inconclusive imaging and histopathological findings.

A nationwide multicenter study of the cost effectiveness of five leading drugs for pharmacological management of cervicobrachial symptoms.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

Anterior fusion surgery with overcorrection in the treatment of adolescent idiopathic scoliosis with Lenke 1 AR curve type: how to achieve overcorrection and its effect on postoperative spinal alignment.

BACKGROUND: The efficacy of anterior fusion with overcorrection in the instrumented vertebra for Lenke 1 AR type curves has been reported, but how to achieve overcorrection and how overcorrection affects spinal alignment are unclear. The purpose of this study was to identify the factors that cause overcorrection, and to investigate how overcorrection affects postoperative spinal alignment in the surgical treatment of Lenke 1 AR type curves. METHODS: Patients who had anterior surgery for a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) type scoliosis and minimum 2-year follow-up were included. The radiographic data were measured at preoperative, postoperative 1 month, and final follow-up. The UIV-LIV Cobb angle was determined as the Cobb angle between the upper instrumented vertebra (UIV) and the lower instrumented vertebra (LIV), and a negative number for this angle was considered overcorrection. The screw angle was determined to be the sum of the angle formed by the screw axis and the lower and upper endplates in the LIV and UIV, respectively. The change (Δ) in the parameters from postoperative to final follow-up was calculated. The relationships between the UIV-LIV Cobb angle and other radiographic parameters were evaluated by linear regression analyses. RESULTS: Fourteen patients met the inclusion criteria. Their median age was 15.5 years, and the median follow-up period was 53.6 months. The median UIV-LIV Cobb angle was -1.4° at postoperative 1 month. The median screw angle was 4.7°, and overcorrection was achieved in 11 (79%) cases at postoperative 1 month. The screw angle (r2 = 0.42, p = 0.012) and Δ FDUV-CSVL (the deviation of the first distal uninstrumented vertebra from the central sacral vertical line, r2 = 0.53, p = 0.003) were significantly correlated with the UIV-LIV Cobb angle. CONCLUSIONS: Screw placement in the UIV and LIV not parallel to the endplate, but angled, was an effective method to facilitate overcorrection in the instrumented vertebrae. The results of the present study suggest that overcorrection could bring spontaneous improvement of coronal balance below the instrumented segment during the postoperative period.

Synovial chondromatosis: Rare involvement of metacarpophalangeal joint and diagnostic challenges in MR imaging.

Synovial chondromatosis (SC) is a rare benign tumor of the cartilaginous tissue that frequently affects large joints intra-articularly. Characteristic imaging findings were reported for the diagnosis of SC. Herein, we report a case of SC of the metacarpophalangeal joint with atypical MRI findings. Considering the clinical presentation, erosion, absence of calcification on X-ray and CT, and low intensity on short tau inversion recovery (STIR), tenosynovial giant cell tumor was the initially diagnosis. However, histopathological findings revealed SC with fibrosis, which was confirmed using Elastica Van Gieson (EVG) staining. In general, low intensity on STIR in SC indicate calcification; however, it can also represent fibrosis in SC. In this case, the diagnosis of SC using MRI was limited highlighting the importance of histopathological findings for an accurate diagnosis of SC.

The Utility and Appropriateness of Single-Position Circumferential Lumbar Interbody Fusion Using O-Arm-Based Navigation in the Novel Oblique Position.

PURPOSE: Single-position surgery with patients in a lateral position, which involves inserting percutaneous pedicular screws (PPS) and lateral interbody fusion (LIF) to avoid changing the position, has been reported. The purpose of the present study was to evaluate the utility and appropriateness of single-position LIF-PPS using O-arm-based navigation in the innovative oblique position. METHODS: This study involved a retrospective analysis of 92 consecutive patients with lumbar spondylolisthesis who underwent LIF-PPS using O-arm-based navigation. Thirty-five subjects demonstrated surgery with repositioning, as well as 24 in the lateral decubitus position, and 33 in the oblique during PPS, where the position was changed to the lateral decubitus position using bed rotation without resetting. We compared these three groups in terms of the surgery time, blood loss, and the accuracy of the screw placement. RESULTS: The operative time was significantly shorter in the single-position surgery, both in the lateral and oblique positions, compared to surgery in a dual position. The blood loss was significantly increased in the lateral position compared to the dual and oblique positions. The screw trajectory angle on the downside was significantly smaller in the lateral position, and the accuracy of the screw placement on the downside was significantly lower in the lateral position compared to the dual and oblique positions. CONCLUSION: Single-position surgery could reduce the average surgery time by about 60 min. The present study indicated the oblique position during PPS insertion might make single-position surgery more useful to improve the accuracy of PPS on the downside, with less blood loss.

Assessment of Changes in Hindfoot Alignment of Total Ankle Arthroplasty for Ankle Osteoarthritis on Weightbearing Subtalar X-ray View.

Background: Recovering normal hindfoot alignment and correcting deformity of the ankle joint following total ankle arthroplasty (TAA) in osteoarthritis (OA) is essential for improving clinical outcomes and increasing long-term survival. We aim to evaluate hindfoot alignment following standard TAA compared to TAA with a total talar prosthesis ("combined TAA") in varus-type OA patients. Methods: This retrospective study was conducted between 2010 and 2022. We included 27 patients (30 feet) who underwent standard TAA and 19 patients (22 feet) who underwent combined TAA. Hindfoot alignment at the subtalar joint was measured by weightbearing subtalar radiographic view before and after surgery. Results: In the standard TAA, the angle between the tibial shaft axis and the articular surface of the talar dome joint (TTS) changed from 75 to 87 degrees (P < .01), the angle between the tibial axis and the surface on the middle facet (TMC) from 89 to 94 degrees (P < .01), and the angle between the tibial axis and the surface on the posterior facet (TPC) from 80 to 84 degrees (P < .01). The angle between the articular surface of the talar dome and the posterior facet of the calcaneus (SIA) decreased from 4.7 to -2.5 degrees (P < .01). In the combined TAA, TTS angle changed from 77 to 88 degrees (P < .01), TMC angle from 93 to 101 degrees (P < .01), TPC angle from 84 to 90 degrees (P < .05), and SIA from 6.6 to 2.1 degrees (P < .01). Varus deviation to the subtalar joint (TMC, TPC) significantly improved postoperatively in both groups. However, TPC was smaller than TTS and SIA was negative in standard TAA, and TPC was larger than TTS and SIA was positive in combined TAA. Conclusion: The amount of correction of the subtalar joint differed depending on the ligament dissection of the subtalar joint and shape of the talar component. Level of Evidence: Level III, retrospective cohort study.

Primary Synovial Sarcoma of the Bone: A Case Report and Literature Review.

BACKGROUND/AIM: Synovial sarcoma (SS), a spindle cell sarcoma, typically occurs in the soft tissues of the extremities and rarely develops in the bones as a primary tumor. To our knowledge, no case of SS in the metacarpal bone has been reported. CASE REPORT: We report a case of primary SS of the metacarpal bone. Considering the clinical and imaging findings, SS was difficult to diagnose; therefore, we performed an open biopsy. Next, we performed a wide resection following the management guidelines for SS of the soft tissue. Immunohistochemistry (IHC) showed positive staining for SS18:SSX and SSX, and fluorescence in situ hybridization showed positive staining for the SS18 split. Owing to FNCLCC grade 3 tumor and the R1 margin, adjuvant chemotherapy with ifosfamide and doxorubicin was initiated. Finally, SS of the bone was diagnosed. Furthermore, we reviewed a total of 37 published cases of primary bone SS, including our case. Age and sex were almost the same in all cases of bone SS, and the most frequent site was the long bone in the lower extremity. CONCLUSION: IHC for SS18::SSX and SSX antibodies are beneficial for diagnosing general SS and SS of the bone. Moreover, SS of the bone should be considered in the differential diagnosis of spindle cell sarcomas of the bone. Wide resection and chemotherapy are recommended as current treatment strategies, although further studies are required regarding treatment validity.

Comparative Study for Characteristics of Locomotive Syndrome in Patients with Lumbar Stenosis and Adult Spinal Deformity.

INTRODUCTION: The differential diagnoses of lumbar spinal stenosis (LSS) and adult spinal deformity (ASD) have been demonstrated primarily using sagittal radiographic spinopelvic parameters. However, it is more important to know the differences in the characteristic clinical symptoms to make accurate treatment decisions. Recently, the relationship between spinal disease and Locomotive Syndrome (LS) has been reported. Additionally, the Geriatric Locomotive Function Scale-25 (GLFS-25) was reported to be a useful scale to evaluate disease severity and characteristic clinical symptoms in spinal disease. METHODS: Sixty-nine consecutive patients with ASD and 196 patients with LSS who underwent spinal surgery were included. Locomotive dysfunction was evaluated using the GLFS-25 questionnaire and physical performance tests including the two-step test and the stand-up test, measured preoperatively. The correlations between sagittal spinopelvic parameters of ASD and LS were examined. RESULTS: All subjects with lumbar degenerative disease in the present study were diagnosed with LS preoperatively. The severity of LS in patients with LSS and ASD were statistically similar. GLFS-25 scores in the mobility and community domain were similarly poor in both groups. Several scores in the domestic life and self-care domains were significantly worse in the ASD group. Question 20 of the GLFS-25, related to load-bearing tasks and housework, was significantly associated with a large pelvic incidence in ASD patients. CONCLUSIONS: Lumbar degenerative disease requiring surgery severely affects the LS of older people. ASD patients had more difficulty with load-bearing tasks and housework such as cleaning the yard, carrying heavy bedding, dressing, and bathing compared to LSS patients.

Nationwide Survey of the Surgical Complications Associated with Lateral Lumbar Interbody Fusion in 2015-2020.

Introduction: Lateral lumbar interbody fusion (LLIF) has been introduced in Japan in 2013. Despite the effectiveness of this procedure, several considerable complications have been reported. This study reported the results of a nationwide survey performed by the Japanese Society for Spine Surgery and Related Research (JSSR) on the complications associated with LLIF performed in Japan. Methods: JSSR members conducted a web-based survey following LLIF between 2015 and 2020. Any complications meeting the following criteria were included: (1) major vessel, (2) urinary tract, (3) renal, (4) visceral organ, (5) lung, (6) vertebral, (7) nerve, and (8) anterior longitudinal ligament injury; (9) weakness of psoas; (10) motor and (11) sensory deficit; (12) surgical site infection; and (13) other complications. The complications were analyzed in all LLIF patients, and the differences in incidence and type of complications between the transpsoas (TP) and prepsoas (PP) approaches were compared. Results: Among the 13,245 LLIF patients (TP 6,198 patients [47%] and PP 7,047 patients [53%]), 389 complications occurred in 366 (2.76%) patients. The most common complication was sensory deficit (0.5%), followed by motor deficit (0.43%) and weakness of psoas muscle (0.22%). Among the patient cohort, 100 patients (0.74%) required revision surgery during the survey period. Almost half of the complications developed in patients with spinal deformity (183 patients [47.0%]). Four patients (0.03%) died from complications. Statistically more frequent complications occurred in the TP approach than in the PP approach (TP vs. PP, 220 patients [3.55%] vs. 169 patients [2.40%]; p<0.001). Conclusions: The overall complication rate was 2.76%, and 0.74% of the patients required revision surgery because of complications. Four patients died from complications. LLIF may be beneficial for degenerative lumbar conditions with acceptable complications; however, the indication for spinal deformity should be carefully determined by the experience of the surgeon and the extent of the deformity.

Clinical differences in preoperative symptoms and surgical outcomes between early and late-teen patients with Lenke type 5C adolescent idiopathic scoliosis.

PURPOSE: This study aimed to compare the clinical features and postoperative outcomes in patients with Lenke type 5C AIS in the early and late teens. METHODS: The study included eligible patients with AIS aged < 20 years with Lenke type 5C curves who underwent selective thoracolumbar/lumbar (TL/L) fusion. The patients were divided into two groups according to the age: younger (11-15 years) and older (16-19 years). Demographic data, radiographic parameters, and 22-item scoliosis research society questionnaire (revised) (SRS-22r) scores were compared. RESULTS: Seventy-three (female: 69, male: 4, mean age: 15.1 years) patients were included. There were 45 and 28 patients in the younger and older groups, respectively. The older group exhibited a significantly smaller TL/L curve than the younger group, whereas no between-group differences were identified regarding curve flexibility and fusion length. The change in coronal balance and subjacent disc angle from preoperative to 2 years after surgery was significantly greater in the younger group, although each curve was equally corrected. Preoperative SRS-22r scores in the older group were significantly worse; however, they improved to the level of the younger group at 2 years after surgery. Postoperative coronal malalignment was observed in six patients (21.4%) in the older group, whereas no cases in the younger group (p < 0.05). CONCLUSION: In patients with Lenke type 5C AIS, we showed that late teens had significantly worse SRS-22r scores than did early teens. Postoperative coronal malalignment was frequently observed in the late teens due to the reduced ability of compensation by subjacent disc wedging.

Advancing Tissue Factor-targeted Therapy for Osteosarcoma via Understanding its Role in the Tumor Microenvironment.

Coagulation activation is associated with cancer progression and morbidity. Recently, mechanisms through which coagulation proteases drive the tumor microenvironment (TME) have been elucidated. This review aims to develop a new strategy dependent on the coagulation system for treating osteosarcoma (OS). We focused on tissue factor (TF), the main initiator of the extrinsic coagulant pathway, as a target for OS treatment. It was found that cell surface-TF, TF-positive extracellular vesicles, and TF-positive circulating tumor cells could drive progression, metastasis, and TME in carcinomas, including OS. Thus, targeting tumor-associated coagulation by focusing on TF, the principle catalyst of the extrinsic pathway, TF is a promising target for OS.

Relationship between floating toes condition and lower limb muscle weight in 8-year-old children: the Yamanashi adjunct study of the Japan Environment and Children's Study (JECS-Y).

[Purpose] Floating toe is a condition in which the toes make insufficient contact with the ground. Weak muscle strength is reportedly one cause of floating toe. However, little evidence exists regarding the relationship between foot muscle strength and floating toe. Here we examined the relationship between foot muscle strength and floating toe by investigating the children' lower extremity muscle mass and floating toe conditions. [Participants and Methods] This cohort study enrolled 118 8-year-old children (62 females, 56 males) with recorded footprints and muscle mass evaluations using dual-energy X-ray absorptiometry. We calculated the floating toe score using the footprint. We measured the muscle weights and the muscle weights divided by the lengths of the lower limbs separately on the left and right sides using dual-energy X-ray absorptiometry. [Results] No significant correlations were observed between the floating toe score and muscle weights or muscle weights divided by lower-limb lengths for either gender or side. [Conclusion] In this study, no significant correlation was found between floating toe degree and lower limb muscle mass, suggesting that lower limb muscle strength is not the primary cause of floating toe, at least in children.

Radiological Assessment of Postoperative Paraspinal Muscle Changes After Lumbar Interbody Fusion With or Without Minimally Invasive Techniques.

STUDY DESIGN: Retrospective cohort study. BACKGROUND: Percutaneous pedicle screws (PPS) have the advantage of being able to better preserve the paraspinal muscles when compared with a traditional open approach. However, the nature of changes in postoperative paraspinal muscle after damage by lumbar fusion surgery has remained largely unknown. It is clinically important to clarify and compare changes in paraspinal muscles after the various surgeries. OBJECTIVE: (1) To determine postoperative changes of muscle density and cross-sectional area using computed tomography (CT), and (2) to compare paraspinal muscle changes after posterior lumbar interbody fusion (PLIF) with traditional open approaches and minimally invasive lateral lumbar interbody fusions (LLIF) with PPS. METHODS: We included data from 39 consecutive female patients who underwent open PLIF and 23 consecutive patients who underwent single-staged treatment with LLIF followed by posterior PPS fixation at a single level (L4-5). All patients underwent preoperative, 6 months postoperative, and 1-year postoperative CT imaging. Measurements of the cross-sectional area (CSA) and muscle densities of paraspinal muscles were obtained using regions of interest defined by manual tracing. RESULTS: We did not find any decrease of CSA in any paraspinal muscles. We did find a decrease of muscle density in the multifidus at 1 year after surgery in patients in the PILF group, but not in those in LLIF/PPS group. CONCLUSIONS: One year after surgery, a significant postoperative decrease of muscle density of the multifidi was observed only in patients who underwent open PLIF, but not in those who underwent LLIF/PPS.