藤田 順之

BACKGROUND: Posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) has a potential risk for postoperative pleural effusion. Although pleural effusion at an early period after PSF for AIS occurs with a relatively high frequency and occasionally requires some treatments, the impact of postoperative pleural effusion on future pulmonary function or lung volume (LV) has not been clarified to date. The aim of this study was to evaluate the effect of pleural effusion after PSF for AIS on the postoperative pulmonary function and LV. METHODS: A total of 114 consecutive patients who underwent PSF for AIS followed up greater than 2 years at our institute were retrospectively reviewed. We evaluated postoperative pleural effusion by computed tomography (CT) at the 1-week follow-up and divided patients into the pleural effusion (PF) and non-pleural effusion (NP) groups. We investigated spirometry parameters recorded for testing included vital capacity (VC), forced expiratory volume in the first second (FEV1), %VC, and FEV1% and measured the LV using CT images and a workstation at baseline and 2 years after surgery. RESULTS: A total of 87 (76.3%) patients with postoperative pleural effusion were identified, but all patients were asymptomatic and did not require additional treatment for postoperative pleural effusion. All pulmonary function parameters at the 2-year follow-up exhibited no significant differences between the two groups. Although preoperative left LV (1.21±0.30 L vs. 1.36±0.34 L; p=.022) and total LV (2.68±0.62 L vs. 2.99±0.73 L; p=.031) were significantly lower in the PF group than in the NP group, all postoperative LV parameters were similar between the two groups. CONCLUSIONS: Pleural effusion at an early period after PSF for AIS was a postoperative occurrence without an impact on future pulmonary function and LV.

Bone marrow endothelial cells (BMECs) play a key role in bone formation and haematopoiesis. Although recent studies uncovered the cellular taxonomy of stromal compartments in the bone marrow (BM), the complexity of BMECs is not fully characterized. In the present study, using single-cell RNA sequencing, we defined a spatial heterogeneity of BMECs and identified a capillary subtype, termed type S (secondary ossification) endothelial cells (ECs), exclusively existing in the epiphysis. Type S ECs possessed unique phenotypic characteristics in terms of structure, plasticity and gene expression profiles. Genetic experiments showed that type S ECs atypically contributed to the acquisition of bone strength by secreting type I collagen, the most abundant bone matrix component. Moreover, these cells formed a distinct reservoir for haematopoietic stem cells. These findings provide the landscape for the cellular architecture in the BM vasculature and underscore the importance of epiphyseal ECs during bone and haematopoietic development.

OBJECTIVE: To investigate the characteristics and symptoms of patients with hip osteoarthritis that are associated with spatiotemporal gait parameters, including their variability and asymmetry. DESIGN: A retrospective, cross-sectional study. SETTING: University hospital. PARTICIPANTS: The study analyzed the gait analysis data of 155 patients (N=155) with hip osteoarthritis who were admitted to a university hospital for total hip replacement and were able to walk on a treadmill without a handrail. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The dependent variables were gait parameters during treadmill walking. These included gait speed, stride length, cadence, coefficient of variation of stride length and stride time, swing time symmetry index, and step symmetry index. Single and multiple regression analyses were conducted using independent variables of the characteristics and symptoms of the patients, including age, sex, height, pain, leg-length discrepancy, and muscle strength of the affected and normal sides measured with a hand-held dynamometer (iliopsoas, gluteus medius, and quadriceps). RESULTS: In the analysis, gait speed and stride were the dependent variables, whereas age, height, and muscle strength on the affected side were the significant independent variables (P<.05). Additionally, pain demonstrated a marginal association with gait speed (P=.053). Only the leg-length discrepancy correlated with cadence. When the coefficient of variation of the stride length was the dependent variable, age and muscle strength on the affected side were significant. For the swing time symmetry index, only the muscle strength on the affected side was significant. Furthermore, the step symmetry index only correlated with leg-length discrepancy. The muscle strength on the affected side was the only significant independent variable for the coefficient of variation of the stride time. CONCLUSIONS: The results revealed that each of the frequent clinical symptoms of hip osteoarthritis, such as pain, muscle weakness, and leg-length discrepancy, can explain different aspects of gait performance.

Background and Objectives: There are several advantages of using lateral lumbar interbody fusion (LLIF) for correction surgeries for adult spinal deformity (ASD); however, we currently have unresolved new issues, including occasional anterior longitudinal ligament (ALL) rupture during the posterior correction procedure. When LLIF was initially introduced, only less lordotic cages were available and ALL rupture was more frequently experienced compared with later periods when more lordotic cages were available. We performed finite element analysis (FEA) regarding the mechanism of ALL rupture during a posterior correction procedure. Methods: A spring (which mimics ALL) was introduced at the location of ALL in the FEA and an LLIF cage with two different lordotic angles, 6 and 12 degrees (6DC/12DC), was employed. To assess the extent of burden on the ALL, the extension length of the spring during the correction procedure was measured and the location of the rotation center was examined. Results: We observed a significantly higher degree of length extension of the spring during the correction procedure in the FEA model with 6DC compared with that of 12DC. We also observed that the location of the rotation center was shifted posteriorly in the FEA model with 6DC compared with that of 12DC. Conclusions: It is considered that the posterior and rostral edge of the less lordotic angle cage became a hinge, and the longer lever arm increased the burden on ALL as the principle of leverage. It is important to use an LLIF cage with a sufficient lordotic angle, that is compatible with the degree of posterior osteotomy in ASD correction.

OBJECTIVES: Although cervical spondylotic myelopathy (CSM) has a marked impact on locomotive function, few studies have evaluated this relationship in terms of locomotive syndrome. Thus, we assessed (i) the stages of locomotive syndrome in preoperative CSM patients using the 25-question geriatric locomotive function scale (GLFS-25), (ii) the correlation between GLFS-25 scores and the Japanese orthopaedic association (JOA) scores or the JOA cervical myelopathy evaluation questionnaire (JOACMEQ) scores, and (iii) the factors associated with stage 3 locomotive syndrome in preoperative CSM patients. METHODS: We used clinical data from 107 patients scheduled for cervical spinal surgery for CSM. Data were collected prior to surgery, and included age, gender, body mass index, medical history, JOA score, and JOACMEQ and GLFS-25 scores. RESULTS: Of the included CSM patients, 93.5% were diagnosed with locomotive syndrome, of whom 77.6% were stage 3 according to GLFS-25 evaluation. For the correlation between GLFS-25 and JOA or JOACMEQ, the upper and lower extremity function scores of JOACMEQ and the JOA were strongly inversely correlated with the GLFS-25 score. Finally, multivariate analysis suggested that severe lower extremity status in the JOACMEQ was significantly associated with stage 3 locomotive syndrome in preoperative CSM patients. CONCLUSIONS: Using the GLFS-25, we found that lower extremity status had the strongest association with stage 3 locomotive syndrome in preoperative CSM patients. These findings are useful for preventing CSM patients from requiring future nursing care.

BACKGROUND: To investigate the possibility of silver (Ag)-induced adverse events and the degree of bone fusion in posterior lumbar interbody fusion surgery using an Ag-containing hydroxyapatite (HA) lumbar interbody cage. METHODS: An Ag-HA cage consisting of highly osteoconductive HA interfused with Ag was developed, and we applied it clinically at three university-affiliated hospitals from April 2020 to December 2020. During the 12-month postoperative observation period, Ag-related adverse events, neuropathy, and postoperative complications were investigated as indicators of safety, while clinical improvement and the fusion status were investigated as indicators of efficacy. Clinical improvement was defined as improvement beyond the minimum clinically important difference (MCID) in the numerical rating scale (NRS; 1.6) for low back and lower limb pain and the Oswestry Disability Index (ODI; 12.8). RESULTS: We performed lumbar interbody fusion using an Ag-HA cage for 48 patients (female, n = 25; mean age, 67.5 years). The mean preoperative NRS was 6.4 (standard deviation, 1.9), while the mean preoperative ODI was 44 [12]. No adverse effects (i.e., argyria) were identified during the 12-month observation period. Surgical site infection occurred in one case, although the implant was preserved via immediate debridement. In total, 39 (81%) participants showed clinical improvement beyond MCID for both NRS and ODI. Bone fusion was achieved at 45 levels (88%) at 6 months and 48 levels (91%) at 12 months postoperatively. CONCLUSIONS: The results of this study suggest that Ag-HA cages can be safely used in spinal fusion procedures and have the potential to prevent postoperative infections, prevent deterioration of the quality of life, and result in favorable outcomes. Larger-scale and longer-term follow-up studies will be required to corroborate these conclusions. Trial registration UMIN 000039964 (date: April 01, 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.

Spinal diseases are commonly associated with pain and neurological symptoms, which negatively impact patients' quality of life. Platelet-rich plasma (PRP) is an autologous source of multiple growth factors and cytokines, with the potential to promote tissue regeneration. Recently, PRP has been widely used for the treatment of musculoskeletal diseases, including spinal diseases, in clinics. Given the increasing popularity of PRP therapy, this article examines the current literature for basic research and emerging clinical applications of this therapy for treating spinal diseases. First, we review in vitro and in vivo studies, evaluating the potential of PRP in repairing intervertebral disc degeneration, promoting bone union in spinal fusion surgeries, and aiding in neurological recovery from spinal cord injury. Second, we address the clinical applications of PRP in treating degenerative spinal disease, including its analgesic effect on low back pain and radicular pain, as well as accelerating bone union during spinal fusion surgery. Basic research demonstrates the promising regenerative potential of PRP, and clinical studies have reported on the safety and efficacy of PRP therapy for treating several spinal diseases. Nevertheless, further high-quality randomized controlled trials would be required to establish clinical evidence of PRP therapy.

Abstract Background Polypharmacy is a growing public health problem occurring in all healthcare settings worldwide. Elderly patients with lumbar spinal canal stenosis (LSS) who manifest low back and neuropathic pain and have a high frequency of comorbidity are predicted to take many drugs. However, no studies have reported polypharmacy in elderly patients with LSS. Thus, we aimed to review the polypharmacy among elderly LSS patients with elective surgeries and examine how the surgical treatment reduces the polypharmacy. Methods We retrospectively enrolled all the patients aged ≥ 65 years who underwent spinal surgery for LSS between April 2020 and March 2021. The prescribed drugs of participants were directly checked by pharmacists in the outpatient department preoperatively and 6-month and 1-year postoperatively. The baseline characteristics were collected beside the patient-based outcomes including Roland–Morris Disability Questionnaire, Zurich Claudication Questionnaire, and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). The cutoff number of drugs for polypharmacy was defined as 6. The prescription drugs were divided into 9 categories: drugs for neuropsychiatric, cardiovascular, respiratory, digestive, endocrine metabolic, and urinary renal diseases; blood products; pain relief medication; and others. Results A total of 102 cases were finally analyzed, with a follow-up rate of 78.0%. Of the participants, the preoperative polypharmacy prevalence was 66.7%. The number of drugs 6-month and 1-year postoperatively was significantly less than the preoperative one. The proportions of polypharmacy at 6 months and 1 year after surgery significantly decreased to 57.8% and 55.9%, respectively. When the prescribed drugs were divided into 9 categories, the number of drugs for pain relief and digestive diseases was significantly reduced after surgery. The multi-variable analysis revealed that a higher score in the psychological disorder of JOABPEQ was associated with 3 or more drugs decreased 1-year postoperatively (OR, 2.5; 95% CI: 1.0–6.1). Conclusion Polypharmacy prevalence was high among elderly LSS patients indicated for lumbar spinal surgery. Additionally, our data showed that lumbar spinal surgery was effective in reducing polypharmacy among elderly LSS patients. Finally, the multi-variable analysis indicated that better psychological condition was associated with the reduction of prescribed drugs after lumbar spinal surgery.

Treatment for lumbar spinal canal stenosis (LSCS) is mainly classified into conservative and surgical therapies. Among conservative therapies, pharmacological treatment is commonly prescribed for LSCS. Meanwhile, surgical treatment is the last option for LSCS. This study aimed to examine the impact of lumbar surgery on pharmacological treatment for patients with LSCS. Consecutive patients aged ≥ 40 years who underwent lumbar surgery for LSCS were identified. A total of 142 patients were retrospectively reviewed for preoperative and 6-month and 1-year postoperative LSCS medications. The results showed that the number of LSCS medications significantly decreased after lumbar surgery. The proportion of the patients taking non-steroidal anti-inflammatory drugs, pregabalin/mirogabalin, opioids, prostaglandin E1 analogs, and neurotropin was significantly decreased after lumbar surgery, but that of the patients taking mecobalamin, acetaminophen, and serotonin-noradrenalin reuptake inhibitors was not significantly changed. Additionally, around 15% of the participants showed an increase in LSCS medications even after lumbar surgery. Multivariable analysis revealed that individuals without improvements in walking ability (RR: 2.7, 95% CI: 1.3–5.9) or social life (RR: 2.3, 95% CI: 1.1–5.0) had a greater risk of a postoperative increase in LSCS medications. The study results may provide physicians with beneficial information on treatment for LSCS.

Oxidative stress (OS) results in many disorders, of which degenerative musculoskeletal conditions are no exception. However, the interaction between OS and ligamentum flavum (LF) hypertrophy in lumbar spinal canal stenosis is not clearly understood. The first research question was whether OS was involved in LF hypertrophy, and the second was whether the antioxidant N-acetylcysteine (NAC) was effective on LF hypertrophy. In total, 47 LF samples were collected from patients with lumbar spinal disorders. The cross-sectional area of LF was measured on axial magnetic resonance imaging. Immunohistochemistry of 8-OHdG and TNF-α were conducted on human LF samples. A positive association was found between 8-OHdG or TNF-α expression and cross-sectional area of LF. Flow cytometry analysis showed that H2O2, buthionine sulfoximine, and TNF-α treatment significantly increased intracellular reactive oxygen species in primary LF cells. NAC inhibited the induction of LF hypertrophy markers by OS or TNF in a real-time reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Western blotting analysis indicated that p38, Erk, and p65 phosphorylation were involved in intracellular OS signaling in LF cells. In conclusion, our results indicated that OS could be a therapeutic target for LF hypertrophy. Although this study included no in vivo studies to examine the longitudinal efficacy of NAC on LF hypertrophy, NAC may have potential as a therapeutic agent against lumbar spinal canal stenosis.

Background and Objectives: Modic type 1 is known to be associated with lower back pain (LBP), but at present, a treatment has not been fully established. Meanwhile, platelet-rich plasma (PRP) has been used for tissue regeneration and repair in the clinical setting. There is no clinical PRP injection trial for the intervertebral disc of LBP patients with Modic type 1. Thus, this study aimed to verify PRP injection safety and efficacy in LBP patients with Modic type 1. As a preliminary experiment, two LBP cases with Modic type 1 are presented. Materials and Methods: PRP was administered intradiscally to two LBP patients with Modic type 1. PRP was obtained from the patients' anticoagulated blood. Primary endpoints were physical condition, laboratory data, and X-ray for safety evaluation. Secondary endpoints were pain scores using the visual analog scale (VAS), the Oswestry Disability Index (ODI), and the Roland-Morris Disability Questionnaire (RDQ) to evaluate PRP efficacy. The observation period was 24 weeks after the PRP injection. In addition, changes in Modic type 1 using MRI were evaluated. Results: This study assessed two LBP patients with Modic type 1. There were no adverse events in physical condition, laboratory data, or lumbar X-rays after injection. Follow-up MRI showed a decrease of high signal intensity on T2WI compared to before PRP administration. The pain scores tended to improve after the injection. Conclusions: PRP injection into the intervertebral disc of LBP patients with Modic type 1 might be safe and effective. This analysis will be continued as a prospective study to establish the efficacy.

INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is a disorder with a three-dimensional spinal deformity and is a common disease affecting 1-5% of adolescents. AIS is also known as a complex disease involved in environmental and genetic factors. A relation between AIS and body mass index (BMI) has been epidemiologically and genetically suggested. However, the causal relationship between AIS and BMI remains to be elucidated. MATERIAL AND METHODS: Mendelian randomization (MR) analysis was performed using summary statistics from genome-wide association studies (GWASs) of AIS (Japanese cohort, 5,327 cases, 73,884 controls; US cohort: 1,468 cases, 20,158 controls) and BMI (Biobank Japan: 173430 individual; meta-analysis of genetic investigation of anthropometric traits and UK Biobank: 806334 individuals; European Children cohort: 39620 individuals; Population Architecture using Genomics and Epidemiology: 49335 individuals). In MR analyses evaluating the effect of BMI on AIS, the association between BMI and AIS summary statistics was evaluated using the inverse-variance weighted (IVW) method, weighted median method, and Egger regression (MR-Egger) methods in Japanese. RESULTS: Significant causality of genetically decreased BMI on risk of AIS was estimated: IVW method (Estimate (beta) [SE] = -0.56 [0.16], p = 1.8 × 10-3), weighted median method (beta = -0.56 [0.18], p = 8.5 × 10-3) and MR-Egger method (beta = -1.50 [0.43], p = 4.7 × 10-3), respectively. Consistent results were also observed when using the US AIS summary statistic in three MR methods; however, no significant causality was observed when evaluating the effect of AIS on BMI. CONCLUSIONS: Our Mendelian randomization analysis using large studies of AIS and GWAS for BMI summary statistics revealed that genetic variants contributing to low BMI have a causal effect on the onset of AIS. This result was consistent with those of epidemiological studies and would contribute to the early detection of AIS.

Objective: Although syringomyelia is considered a risk factor for neurological complications of correction surgery for scoliosis, only a few reports on the surgical results of the correction surgery complicated with associated syringomyelia are available. The purpose of this study is to verify the potential risk of neurological complications due to the presence of syringomyelia and explore the factors affecting the surgical outcomes of posterior correction surgery for scoliosis associated with syringomyelia. Methods: This is a retrospective observational study in a single university hospital setting. Among 754 consecutive patients who underwent posterior correction and fusion surgery for scoliosis from 2009 through 2018 in our institution, we identified 28 patients presenting with spinal syringomyelia on preoperative whole spine MRI. The identified cases comprised 14 males and 14 females aged 11 years to 23 years (14.0 ± 2.9 years), and those with wide-type syrinx within fused spinal levels had undergone surgery for syringomyelia beforehand. First, we investigated the occurrence rate of peri- and postoperative neurological complications. Then we explored the factors affecting the correction rate of the Cobb angle and the incidence of coronal decompensation. Results: Neurological complication (transient sensory deficits in bilateral legs) occurred in one case with thoracic single curve and narrow-type syrinx, disappearing spontaneously within several weeks postoperatively. The cases with an L4 long curve (n = 3, including L4 in thoracolumbar long C-shaped curve) showed a significantly poor correction rate (38.7%, p = 0.003) and developed postoperative coronal decompensation. Conclusions: Prior treatment for wide-type syrinx located within the spinal fusion level effectively prevented severe neurological complications, and when treating cases with long-curve L4 scoliosis associated with syringomyelia, the surgeons should note the occurrence of postoperative coronal decompensation.

Osteosarcoma is a malignant tumor that produces neoplastic bone or osteoid osteoma. In human multicentric osteosarcoma (HMOS), a unique variant of human osteosarcoma (HOS), multiple bone lesions occur simultaneously or asynchronously before lung metastasis. HMOS is associated with an extremely poor prognosis, and effective treatment options are lacking. Using the proteins in our previously generated HMOS cell lines as antigens, we generated antibodies using a human antibody phage library. We obtained antibody clones recognizing 95 independent antigens and developed a fluorescence probe-based enzyme-linked immunosorbent assay (ELISA) technique capable of evaluating the reactivity of these antibodies by fluorescence intensity, allowing simple, rapid, and high-throughput selection of antibody clones. These results were highly correlated with those using flow cytometry. Subsequently, the HMOS cell lysate was incubated with the antibody, the antigen-antibody complex was recovered with magnetic beads, and the protein bands from electrophoresis were analyzed using liquid chromatography-mass spectrometry (LC/MS). CAVIN1/polymerase I transcript release factor was specifically detected in the HMOS cells. In conclusion, we found via a novel high-throughput screening method that CAVIN1/PTRF is an HMOS-specific cell membrane biomarker and an antigen capable of producing human antibodies. In the future, antibody-drug conjugate targeting of these specific proteins may be promising for clinical applications.

Adolescent idiopathic scoliosis (AIS) is a serious health problem affecting 3% of live births all over the world. Many loci associated with AIS have been identified by previous genome wide association studies, but their biological implication remains mostly unclear. In this study, we evaluated the AIS-associated variants in the 7p22.3 locus by combining in silico, in vitro, and in vivo analyses. rs78148157 was located in an enhancer of UNCX, a homeobox gene and its risk allele upregulated the UNCX expression. A transcription factor, early growth response 1 (EGR1), transactivated the rs78148157-located enhancer and showed a higher binding affinity for the risk allele of rs78148157. Furthermore, zebrafish larvae with UNCX messenger RNA (mRNA) injection developed body curvature and defective neurogenesis in a dose-dependent manner. rs78148157 confers the genetic susceptibility to AIS by enhancing the EGR1-regulated UNCX expression. © 2022 American Society for Bone and Mineral Research (ASBMR).

Age-related changes in the posterior extensor muscles of the cervical and lumbar spine have been reported in some studies; however, longitudinal changes in the thoracic spine of healthy subjects are rarely reported. Therefore, this study aimed to evaluate changes in the cross-sectional areas (CSAs) of posterior extensor muscles in the thoracic spine over 10 years and identify related factors. The subjects of this study were 85 volunteers (mean age: 44.7 ± 11.5) and the average follow-up period was about 10 years. The CSAs of the transversospinalis muscles, erector spinae muscles, and total CSAs of the extensor muscles from T1/2 to T11/12 were measured on magnetic resonance imaging. The extent of muscle fat infiltration was assessed by the signal intensity (luminance) of the extensor muscles' total cross-section compared to a section of pure muscle. We applied a Poisson regression model, which is included in the generalized linear model, and first examined the univariate (crude) association between each relevant factor (age, sex, body mass index, lifestyle, back pain, neck pain, neck stiffness, and intervertebral disc degeneration) and CSA changes. Then, we constructed a multivariate model, which included age, sex, and related factors in the univariate analysis. The mean CSAs of the transversospinalis muscles, erector spinae muscles, and total CSAs of the extensor muscles significantly increased over 10 years. Exercise habit was associated with increased CSAs of the erector spinae muscles and the total area of the extensor muscles. The cross-section mean luminance significantly increased from baseline, indicating a significant increase of fat infiltration in the posterior extensor muscles. Progression of disc degeneration was inversely associated with increased fat infiltration in the total extensor muscles.

BACKGROUND: Since osteopenia has been reported to potentially associated with the progression of scoliosis, bone mineral density (BMD) might have some influences on adolescent idiopathic scoliosis (AIS). However, little is known about longitudinal BMD changes in AIS patients. This study aimed to investigate whether osteopenia in preoperative AIS patients persist at bone maturity, and to evaluate the association between BMD and AIS severity. METHODS: We reviewed 61 AIS patients who underwent surgery when they were Risser grade 4 or below and less than 20 years old (16.6 ± 1.9 years), were followed until they were at least 18 years old and had a Risser grade of 5, and followed at least 2 years after the surgery (mean follow-up 4.9 ± 1.7 years). We evaluated radiographical parameters and proximal femur BMD before surgery and at the final follow-up. A BMD of less than the mean minus 1SD was considered as low BMD. Based on preoperative BMD, 37 patients were assigned to normal BMD (N) group (1.02 ± 0.08 g/cm2) and 24 patients to low BMD (L) group (0.82 ± 0.06 g/cm2). RESULTS: All patients in the N-group had normal BMD at the final follow-up. In the L group, 15 patients (62.5%) had low BMD at the final follow-up (L-L group; preoperative 0.79 ± 0.05 g/cm2 and final follow-up 0.78 ± 0.05 g/cm2). The mean preoperative Cobb angle was significantly larger in the L-L group (67.8 ± 11.2°) than in those with normal BMD at the final follow-up (L-N group, 55.6 ± 11.8°) or the N-N group (50.8 ± 7.6°). Preoperative BMD was significantly negative correlated with the preoperative Cobb angle. The age at surgery and mean preoperative BMI were similar in the L-N and L-L groups. CONCLUSIONS: Of AIS patients with low preoperative BMD, 62.5% still had low BMD after reaching bone maturity, and low BMD was associated with the severity of scoliosis.

BACKGROUND: The efficacy of platelet-rich plasma (PRP) for lateral epicondylitis has been demonstrated. However, the healing process monitored by repeated magnetic resonance imaging (MRI) is unclear. The purpose of this study was to evaluate sequential changes using MRI in patients with lateral epicondylitis treated by PRP injection at 6 follow-up visits over a 2-year period. METHODS: Thirty patients who underwent PRP treatment for lateral epicondylitis and sequential MRI evaluation were prospectively enrolled. The MRI scores (ranging from 0 to 3) and clinical scores, including the visual analog scale (VAS) pain score and Patient-Rated Tennis Elbow Evaluation (PRTEE) score, were measured at baseline (before treatment) and 1, 3, 6, 12, 18, and 24 months after the procedure. Sequential changes in the MRI scores and clinical scores during the treatment period were evaluated. In addition, the associations between MRI scores and clinical scores were assessed. RESULTS: The mean MRI score at baseline was 2.30, and the mean MRI scores at 1, 3, 6, 12, 18, and 24 months after the procedure were 1.97, 1.77, 1.13, 0.73, 0.60, and 0.33, respectively. Significant improvements in the MRI scores occurred by 3 months and continued over a period of 24 months. Regarding the clinical scores, the mean VAS pain scores were 72 at baseline, 48 at 1 month, 34 at 3 months, 28 at 6 months, 15 at 12 months, 14 at 18 months, and 11 at 24 months and the mean PRTEE scores were 56, 36, 26, 18, 8, 9, and 6, respectively. Significant improvements in the VAS pain score and PRTEE score occurred by 1 month and continued over a period of 12 months. There was little association between the MRI scores and clinical scores. CONCLUSIONS: Continuous tendon recovery assessed by MRI was found during a 2-year period after PRP treatment. Improvements in the MRI scores followed and continued longer than improvements assessed by the clinical scores.

BACKGROUND CONTEXT: The risk factors for radiographical adjacent segment disease (ASD) in patients with degenerative spondylolisthesis have been previously reported. However, there are only few reports on patients with spondylolytic spondylolisthesis who underwent single-level posterior lumbar interbody fusion (PLIF). PURPOSE: The study aimed to investigate the risk factors for radiographical ASD in patients with L5-S1 spondylolytic spondylolisthesis who underwent single-level PLIF. STUDY DESIGN/SETTING: A retrospective study PATIENT SAMPLE: This study retrospectively reviewed 135 consecutive patients (91 men and 44 women) with symptomatic L5-S1 spondylolytic spondylolisthesis who underwent single-level PLIF. OUTCOME MEASURES: The pre- and postoperative (at the final follow-up) spinopelvic parameters, % slip, sacral slope, lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), PI minus LL (PI - LL), lumbosacral angle, C7 sagittal vertical axis, and thoracic kyphosis were measured using standing radiographs. METHODS: Radiographical ASD was defined as disc height loss (>3 mm), increase of posterior angulation (>5°), or progression of spondylolisthesis (>3 mm) between the pre- and postoperative radiographs. Pfirrmann's classification was used to evaluate disc degeneration. The radiographical parameters and changes between the pre- and postoperative values were evaluated and compared for the non-ASD and ASD groups. Binary logistic regression analysis was performed to evaluate the adjusted associations between each potential explanatory variable and ASD development. RESULTS: The radiographical ASD incidence was 11%. Additionally, 60% of the patients with ASD had radiographical ASD at 1 year and all cases of radiographical ASD in this follow-up period occurred within 3 years after the initial surgery. The mean period of ASD occurrence after initial surgery was 21.7 ± 12.6 months. No patients required reoperation for radiographical ASD. Multivariate analysis revealed that a preoperative (odds ratio [OR], 5.9; 95% confidence interval [CI], 1.2-28.9; p=.03) and a postoperative (OR, 6.5; 95% CI, 1.2-34.5; p=.03) PI - LL of ≥15° were risk factors for radiographical ASD. CONCLUSIONS: Pre- and postoperative PI - LL value mismatch was identified as significant independent risk factors for radiographical ASD in patients with L5-S1 spondylolytic spondylolisthesis. Obtaining larger lordosis at L5-S1 may be the key to preventing radiographical ASD.

CASE: Appendicular fecaliths have been reported to migrate to nearby organs before or during surgical treatment and become a late source of infection. We report an extremely rare case of recurrent iliopsoas abscesses caused by appendicular fecaliths that have migrated to the psoas muscle before or during the previous appendicectomy for acute appendicitis. In this case, surgical removal of fecaliths cured the iliopsoas abscess. CONCLUSION: Orthopaedic surgeons and gastroenterologists should remember that appendicular fecaliths that migrated into the iliopsoas muscle may cause late-onset iliopsoas abscesses.

目的:本研究の目的は,本邦の医療統計データを利用して,腰痛や関節症を含む運動器疾患の平均寿命及び健康寿命に及ぼす影響を算出することである.方法:2016年の簡易生命票,人口動態統計,国民生活基礎調査,介護サービス施設・事業所調査と,2014年および2017年患者調査のデータを利用した.これらのデータから各疾患を除外した際の平均寿命および健康寿命を算出した.運動器疾患としては関節リウマチ,関節症,腰痛,骨粗鬆症,骨折が選択され,運動器疾患以外では,悪性新生物,虚血性心疾患,脳血管障害が選択された.結果:すべての運動器疾患において,除外しても平均寿命にはほとんど影響を与えなかったが,健康寿命は増加した.各疾患の不健康期間への影響を算出すると,悪性新生物を除外した場合,不健康期間が1年以上延びるのに対して,運動器疾患を除外した場合,全ての疾患で不健康期間を減少させ,特に腰痛と関節症を除外すると不健康期間が0.3〜1.5年短縮した.考察:本研究結果から,運動器疾患は平均寿命には影響しないが,健康寿命に影響しており,特に腰痛と関節症が,健康寿命に大きく影響していることが判明した.(著者抄録)

STUDY DESIGN: Multicenter retrospective study. OBJECTIVES: We aim to investigate features of cervical spondylotic myelopathy (CSM) associated with anterior cervical spondylolisthesis (ACS) during posterior decompression surgery. METHODS: A total of 732 patients with CSM were enrolled, who underwent posterior decompression surgery between July 2011 and November 2015 at 17 institutions. The patients with ACS (group A), defined as an anterior slippage of ≥2 mm on plain radiographs, were compared with those without ACS (group non-A). Also, the characteristics of patients with ACS progression (group P), defined as postoperative worsening of ACS ≥2 mm or newly developed ACS, were investigated. Moreover, kyphosis was defined as C2-C7 angle in neutral position ≤-5°. The Japanese Orthopedic Association (JOA) scoring system was used for clinical evaluation. RESULTS: Group A consisting of 62 patients (8.5%) had worse preoperative clinical status but comparable surgical outcomes to group non-A. Furthermore, ACS was associated with greater age, and the degree of slippage did not affect myelopathy grades. Seventeen patients (2.3%) were observed in group P, and preoperative ACS was a significant predisposing factor for the progression without clinical impact. Among the patients in group A, preoperative cervical kyphosis was a risk factor for lower JOA recovery rate. CONCLUSIONS: Although the presence of ACS increases the risk of postoperative progression, it is not a contraindication for posterior decompression. However, surgeons need to consider the indication of fusion surgery for the patients who have ACS accompanied by kyphosis because of the poor surgical outcomes.

STUDY DESIGN: This is a retrospective study. PURPOSE: This study aims to evaluate the risk factor associated with pseudoarthrosis after placement of lateral interbody fusion (LIF) cages for adult spinal deformity (ASD) treatment. OVERVIEW OF LITERATURE: LIF technique is widely used for ASD correction. Furthermore, pseudoarthrosis is a major complication of fusion surgery required for revision surgery. METHODS: This study included 42 patients with ASD (two men and 40 women; 112 segments; mean, 68.5±8.4 years; and mean follow-up, 31.6±17.0 months) who underwent LIF and posterior correction surgery. The concave slot of the LIF cage was filled with an autologous iliac crest bone graft (IBG), and the convex slot with a porous hydroxyapatite/collagen (HAp/Col) composite was soaked with bone marrow aspirate. Endplate injury, the gap between vertebral endplate and cage in the coronal or sagittal plane, and fusion status were evaluated using computed tomography multiplanar reconstruction at 12 months after surgery. Moreover, the associated risk factors for pseudoarthrosis were analyzed. RESULTS: Fusion at LIF segments were observed in 71.4% segments at 12 months after surgery. Fusion on the concave slot (autologous IBG side), convex slot (porous HAp/Col composite side), and both concave and convex slots were observed in 66.1%, 37.5%, and 36.6% of patients, respectively. Moreover, pseudoarthrosis was observed in 28.6% at 12 months after surgery. Consequently, logistic regression analysis of the fusion at the LIF segment revealed that the gap between the LIF cage and endplate in the coronal plane (p=0.030; odds ratio, 0.183; 95% confidence interval, 0.030-0.183) was significantly associated with pseudoarthrosis at the LIF segments. CONCLUSIONS: ASD surgery fusion rate using LIF cages was 71.4% at 12 months after surgery. The fusion rate was higher on the concave slot filled with autologous IBG than on the convex slot filled with a porous HAp/Col composite. The gap in the coronal plane was a risk factor for pseudoarthrosis at the LIF segment.

OBJECTIVES: This study aimed to compare the pre- and postoperative morphology of the median nerve using three-dimensional (3-D) MRI in patients with carpal tunnel syndrome (CTS). METHODS: We assessed 31 patients with CTS who underwent open carpal tunnel release and T2*-weighted MRI of the wrist preoperatively and at 6 months postoperatively. The median nerve morphology was evaluated on the basis of the cross-sectional areas (CSAs) and cross-sectional volumes (CSVs). The association between these MRI findings and nerve conduction studies was also evaluated. RESULTS: The mean preoperative CSA and CSV values at the proximal carpal tunnel level significantly decreased from 22.2 mm2 and 24.4 mm3 to 16.5 mm2 and 18.1 mm3, respectively, postoperatively. Median nerve swelling at the proximal carpal tunnel level was observed in 29 (94%) and 23 (74%) patients before and after surgery, respectively. The mean preoperative CSA and CSV values at the hamate level significantly increased from 9.9 to 12.3 mm2 and from 10.9 to 13.5 mm3 after surgery, respectively. Nerve narrowing at the hamate bone level was preoperatively observed in 28 (90%) patients and postoperatively in 21 (68%) patients. Preoperative CSA and CSV values at the proximal carpal tunnel were significantly associated with preoperative distal motor and sensory latency. CONCLUSIONS: Visual confirmation of the median nerve morphology using 3-D MRI is useful when considering postoperative recovery and explaining the nerve condition to the patients. KEY POINTS: • The 3-D morphology of the median nerve after carpal tunnel release can be delineated using 3-D MRI. • Preoperative swelling of the median nerve in the 2-D and 3-D planes reflects the severity of carpal tunnel syndrome. • Visual confirmation of the median nerve morphology is useful when considering median nerve recovery after carpal tunnel release and for explaining the condition of the nerve to patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Although intramedullary astrocytoma is associated with a high mortality rate, the optimal treatment has not reached a consensus. This study aimed at evaluating neurologic function and overall survival rate (OSR) in the treatment of this tumor. SETTING: The single institution in Japan. METHODS: This study enrolled 67 subjects who underwent surgical treatment for intramedullary astrocytoma. Demographic, imaging, and surgical information were collected from each participant. Tumors were histologically categorized using the World Health Organization classification, and subjects were divided into low-grade (I and II; n = 40) and high-grade (III and IV; n = 27) groups. Neurologic status was evaluated using the modified McCormick scale (MMS). OSR was assessed using Kaplan-Meier methods. RESULTS: The OSR decreased when the pathological grade increased (p < 0.01). Regarding the therapeutic efficacy for low-grade astrocytomas, subjects who underwent gross total resection (GTR) showed a higher OSR than those who did not (p = 0.02). GTR prevented worsening of MMS score, while non-GTR increased the MMS score (p < 0.01). In the high-grade group, 19 and 10 underwent radiation therapy and chemotherapy, respectively. However, both treatments did not improve OSR. Cordotomy was performed for subjects whose lesional area was at the thoracic level, but the OSR did not significantly increase. CONCLUSIONS: The most beneficial therapeutic strategy for low-grade astrocytomas was GTR, whereas that for the high-grade tumors was unclear. Further studies with a larger sample size are warranted to validate the effective treatment for malignant astrocytomas.

BACKGROUND: Patients with lumbar spinal canal stenosis (LSS) often have peripheral arterial disease and aortic disease based on atherosclerosis. Oxidized LDL, which is clinically involved in the development of atherosclerosis, may also influence LF hypertrophy, but the function of the oxidized low-density lipoprotein (LDL)/lectin-type oxidized LDL receptor 1 (LOX-1) system in LF hypertrophy is unknown. We aimed to elucidate the potential involvement of oxidized LDL/LOX-1 system in ligamentum flavum (LF) hypertrophy. METHODS: A total of 43 samples were collected from LF tissues of the patients who underwent posterior lumbar spinal surgery. Immunohistochemistry for LOX-1 was performed using human LF samples. We treated the cells in vitro with inflammatory cytokines TNF-α and IL-1β, oxidized LDL, and simvastatin. The expressions of LOX-1 and LF hypertrophy markers including type I collagen, Type III collagen, and COX-2 were assessed by real-time RT-PCR and immunocytochemistry. Phosphorylation of MAPKs and NF-κb was evaluated by Western blot after treatment with TNF-α, IL-1β, oxidized LDL, and simvastatin. RESULTS: A significant weak correlation was observed between the number of positive cells of LOX-1 and cross-sectional area of LF on preoperative axial magnetic resonance imaging. In functional analysis, simvastatin treatment neutralized the oxidized LDL-mediated induction of mRNA expressions of LF hypertrophy markers. Western blot analysis showed that oxidized LDL as well as TNF-α and IL-1β activated the signaling of MAPKs and NF-κb in LF cells, and that simvastatin treatment reduced the phosphorylation of all signaling. The TNF-α and IL-1β treatments increased both mRNA and protein expression of LOX-1 in LF cells. CONCLUSION: We found a link between the oxidized LDL/LOX-1 system and LF hypertrophy. In addition, our in vitro analysis indicate that oxidized LDL may affect LF hypertrophy through signaling of MAPKs. Our results suggest that the oxidized LDL/LOX-1 system may be a potential therapeutic target for LSS.

AIMS: Elderly patients with musculoskeletal disorders are generally expected to receive many prescription drugs for non-musculoskeletal comorbidities and for alleviating chronic musculoskeletal pains. The aims of this study were to review the use of prescription drugs in elderly patients with elective surgeries for musculoskeletal disorders and to identify the factors associated with polypharmacy in elderly patients with musculoskeletal disorders. METHODS: We retrospectively collected the clinical data of patients aged ≥65 years who underwent knee arthroplasty, total hip arthroplasty, or spinal surgery for lumbar or cervical degenerative disorders at our institution. The following data were evaluated: age, body mass index, sex, surgical site, prescription drugs used, American Society of Anesthesiologists physical status grade, and medical history, including hypertension, hyperlipidemia, diabetes, stroke, malignancy, and smoking. Polypharmacy was defined as the use of six or more drugs. RESULTS: In the present study, 767 consecutive patients were evaluated retrospectively. The prevalence of polypharmacy was >50% in the elderly patients with musculoskeletal disorders. The mean numbers of total drugs and pain relief medications were significantly higher in the lumbar surgery group than in the other surgery groups. Multivariable analysis revealed that the factors associated with polypharmacy were lumbar surgery, hypertension, hyperlipidemia, diabetes, and malignancy. CONCLUSIONS: This is the first study to cross-sectionally review the drugs prescribed to patients with degenerative musculoskeletal disorders. It clearly identified the factors associated with polypharmacy in elderly patients with degenerative musculoskeletal disorders. Particular attention should be paid to polypharmacy in elderly patients with lumbar degenerative disorders. Geriatr Gerontol Int 2022; 22: 121-126.