Prospective Registration Study for Establishing Minimal Clinically Important Differences in Patients Undergoing Surgery for Spinal Metastases.

STUDY DESIGN: Multicenter, prospective registry study. OBJECTIVE: To clarify minimal clinically important differences (MCIDs) for surgical interventions for spinal metastases, thereby enhancing patient care by integrating quality of life (QoL) assessments with clinical outcomes. SUMMARY OF BACKGROUND DATA: Despite its proven usefulness in degenerative spinal diseases and deformities, the MCID remains unexplored regarding surgery for spinal metastases. METHODS: This study included 171 (out of 413) patients from the multicenter "Prospective Registration Study on Surgery for Metastatic Spinal Tumors" by the Japan Association of Spine Surgeons. These were evaluated preoperatively and at 6 months postoperatively using the Face scale, EuroQol-5 Dimensions-5 Levels (EQ-5D-5L), including the visual analog scale (VAS), and performance status. The MCIDs were calculated using an anchor-based method, classifying participants into the improved, unchanged, and deteriorated groups based on the Face scale scores. Focusing on the improved and unchanged groups, the change in the EQ-5D-5L values from before to after treatment was analyzed, and the cutoff value with the highest sensitivity and specificity was determined as the MCID through receiver operating characteristic curve analysis. The validity of the MCIDs was evaluated using a distribution-based calculation method for patient-reported outcomes. RESULTS: The improved, unchanged, and deteriorated groups comprised 121, 28, and 22 participants, respectively. The anchor-based MCIDs for the EQ-5D-5L index, EQ-VAS, and domains of mobility, self-care, usual activities, pain/discomfort, and anxiety/depression were 0.21, 15.50, 1.50, 0.50, 0.50, 0.50, and 0.50, respectively; the corresponding distribution-based MCIDs were 0.17, 15,99, 0.77, 0.80, 0.78, 0.60, and 0.70, respectively. CONCLUSION: We identified MCIDs for surgical treatment of spinal metastases, providing benchmarks for future clinical research. By retrospectively examining whether the MCIDs are achieved, factors favoring their achievement and risks affecting them can be explored. This could aid in decisions on surgical candidacy and patient counseling.

Trends in infectious spondylitis from 2000 to 2020.

PURPOSE: This study aimed to investigate the trends in infectious spondylitis over the past two decades. METHODS: We included 157 cases, from 2000 to 2020, of infectious spondylitis. The cases were divided into two groups: 00 (cases during 2000-2009; 82 cases:) and 10 (cases during 2010-2020; 75 cases) groups. Patients' age, sex, causative organism, and localization were examined and compared between the two groups. RESULTS: The proportions of women in the 00 and 10 groups were 30.5% and 38.7%, respectively, with no significant difference (P = 0.28). The average age was significantly higher in the 10 group (72.6 years) than in the 00 group (68.8 years; P < 0.01). A compromised host was the cause of infection in 52.4% and 36.0% of the patients in the 00 and 10 groups, respectively, showing a significant difference. The bacterial identification rates were 70.1% and 77.3% in the 00 and 10 groups, respectively (P < 0.01), and the genus Staphylococcus was the most common bacteria. The proportions of resistant bacteria such as methicillin-resistant Staphylococcus aureus in the 00 and 10 groups were 27.3% and 6.7%, respectively (P < 0.01). Conversely, infectious diseases caused by indigenous bacteria in the oral cavity and intestines were more common in the 10group (37.8%) than in the 00 group (13.0%), showing a significant difference (P < 0.01). CONCLUSION: Recently, infections caused by indigenous bacteria in the oral cavity and intestines have increased more than those caused by resistant bacteria over the past two decade.

Association between phase angle and clinical outcomes in patients with lumbar spinal stenosis from the preoperative to 12-month postoperative period: A prospective observational study.

No reports of longitudinal studies on phase angle (PhA) in lumbar spinal stenosis (LSS) exist, and its association with postoperative clinical outcomes is unclear. We longitudinally investigated PhA in patients with LSS preoperatively to 12 months postoperatively and determined the association between PhA and the Japanese Orthopedic Association (JOA) score. This prospective observational study included patients who underwent consecutive surgical treatments for clinically and radiologically defined LSS. Outcome measures including walking speed, Timed Up and Go test (TUG), JOA score, and PhA based on bioelectrical impedance analysis were measured preoperatively and at 3, 6, and 12 months postoperatively. Correlations between PhA and the JOA score and motor function were analyzed. The effect of PhA on JOA scores was evaluated using mixed-effect models for repeated measurements (MMRM). Eighty-nine patients were included at baseline, and 85, 85, and 78 patients were analyzed at 3, 6, and 12 months postoperatively, respectively. PhA was 3.9 ± 0.8 (p = 0.086), 4.0 ± 0.8 (p = 0.644), and 4.1 ± 0.9 (p = 0.791) at 3, 6, and 12 months postoperatively and 4.2 ± 0.8 at baseline. PhA was significantly correlated with the JOA score (p < 0.01) and walking speed and TUG results (p < 0.01) at all assessment points. In the MMRM, PhA was associated with the JOA score at all assessment points. Changes in postoperative JOA scores after lumbar spine surgery are associated with PhA at each assessment time point. PhA may be a useful postoperative clinical indicator after surgery for LSS.

Efficacy of Subtraction Computed Tomography Arteriography During Preoperative Embolization in Spinal Tumors.

Background: This study aimed to evaluate the efficacy of subtraction computed tomography arteriography (s-CTA) during preoperative embolization in spinal tumors. Methods: The study analyzed 17 vertebrae in 13 patients who underwent preoperative embolization before spinal fixation surgery for malignant spinal tumors to decrease blood loss at our hospital from 2019 to 2021. Their ages ranged from 56 to 88 years (average, 73.5 years). Metastatic bone tumors were most common, including five cases originating as lung carcinomas and three as renal cancers. After digital subtraction angiography of selected tumor-feeding arteries and non-subtraction CTA (ns-CTA) were performed, s-CTA was conducted using data obtained from both procedures. A clarity score of the boundary between the normal bone and tumor was derived for each patient, which was then classified into four grades (good, 3 points; fair, 2 points; faint, 1 point; poor, 0 points) by two experienced radiologists, followed by a comparison between the s-CTA and ns-CTA groups using the Wilcoxon signed-rank test. Results: Clarity scores were significantly higher in the s-CTA group than in the ns-CTA group (P < 0.001). The agreement of Cohen's coefficients between the two radiologists was κ = 0.724 in s-CTA scoring and κ = 0.622 in ns-CTA scoring, which were moderately matched. Seven arteries were not embolized due to insufficient tumor contrast enhancement and their poor relation to the surgical invasion zone. No complications were observed during or after embolization. Conclusion: S-CTA successfully distinguished between tumor and normal bone and may help avoid unnecessary embolization.

Comprehensive analysis of microRNA expression in lumbar facet joint capsules and synovium of patients with osteoarthritis: Comparison between early-stage and late-stage osteoarthritis samples from a single individual.

BACKGROUND: MicroRNA is attracting attention as a therapeutic target for osteoarthritis. We focused on joint capsules and synovium in lumbar facet joint osteoarthritis. The purpose of this study was to identify microRNAs that are upregulated in lumbar facet joint capsules and synovium with osteoarthritis. METHODS: We included patients who underwent spinal fusion for degenerative lumbar spine diseases. We selected patients who had both early-stage and late-stage facet joint osteoarthritis in a single individual. We extracted joint capsule and synovium samples from these patients and isolated microRNAs. During the screening phase, we compared early-stage and late-stage osteoarthritis samples from the same individual. We identified microRNAs with >2-fold change in expression in 75% or more of patients with late-stage osteoarthritis using next generation sequencing. During the technical validation phase, the same samples were used for real-time polymerase chain reaction. We identified microRNAs with >2-fold change in expression in 62.5% or more of patients with late-stage osteoarthritis. RESULTS: Of 40 patients who underwent spinal fusion, we selected eight patients with both early-stage and late-stage facet joint osteoarthritis. During the screening phase, we identified eight upregulated microRNAs out of 2274 microRNAs in late-stage OA. In late-stage OA, two microRNAs (miR-133a-5p and miR-144-3p) were upregulated in seven patients and six microRNAs (miR-133a-3p, miR-133b, miR-206, miR-20a-5p, miR-301a-3p, and miR-32-5p) were upregulated in six patients. During the technical validation phase, we found significant upregulation of miR-144-3p expression in late-stage osteoarthritis compared with early-stage osteoarthritis. Expression of the other microRNAs was not significantly different according to the paired-t test. However, miR-133a-3p, miR-133b, and miR-206 were upregulated >2-fold in 62.5% or more of patients with late-stage osteoarthritis. CONCLUSIONS: Some of the microRNAs identified in this study might be involved in joint capsule degeneration or synovitis.

Relationship among Osteoporosis, Sarcopenia, Locomotive Syndrome, and Spinal Kyphosis in Older Individuals Living in a Local Mountain Area.

STUDY DESIGN: Cross-sectional cohort study. PURPOSE: This study investigated the relationship among osteoporosis, sarcopenia, locomotive syndrome, and spinal kyphosis in older individuals living in a mountain area. OVERVIEW OF LITERATURE: Kyphosis greatly reduces the quality of life of older individuals. Osteoporosis and sarcopenia are kyphosiscausing factors. METHODS: This cross-sectional study included 361 individuals aged ≥65 years (mean age, 75.0 years) living in a local mountain area and underwent medical check-ups from 2014 to 2018. The survey items included kyphosis index, body mass index, back pain prevalence, back pain Visual Analog Scale score, Oswestry Disability Index, walking speed, grip strength, skeletal mass index, osteoporosis (% young adult mean [YAM]), LOCOMO 5 score, and presence of sarcopenia (Asian Working Group for Sarcopenia). The participants were divided into the N (kyphosis index: <12; n=229, 63.4%), M (kyphosis index: 12-15; n=99, 27.4%), and K (kyphosis index: ≥15; n=33, 9.2%) groups. p -values of <0.05 were considered statistically significant. An association factor of kyphosis (kyphosis index: ≥15) was investigated with logistic regression analysis. RESULTS: Age and LOCOMO 5 scores were significantly higher (p <0.05) and %YAM and walking speed were significantly lower (p <0.05) in the K group than in the M and N groups. Other survey items showed significant differences. Only %YAM (odds ratio, 0.20; 95% confidence interval, 0.04-0.96) was an independent factor associated with a kyphosis index of ≥15. CONCLUSIONS: Decreased muscle mass and muscle strength would be related to kyphosis; however, no such relations were noted. Bone loss was significantly related to kyphosis. Osteoporosis-induced decrease in vertebral body height is present in the background. Sarcopenia and locomotive syndrome were not related to kyphosis, whereas decreased bone density was independently associated with kyphosis in older individuals living in a mountain area.

Impact of Sarcopenia on Spinal Spondylosis: A Literature Review.

Sarcopenia and spinal spondylosis (SS) are important health challenges among older individuals; however, data regarding the effect of sarcopenia on SS are lacking. Hence, we aimed to organize the existing knowledge on the impact of sarcopenia on SS and explore potential issues in the available literature. We examined the trends and interventions regarding sarcopenia and SS, searching five databases (PubMed, Embase, CINHAL, Web of Science, and Cochrane Library) from inception to January 2023. Sarcopenia-related events were screened, selected, and reviewed, ultimately identifying 19 relevant studies. The identified reports were predominantly retrospective observational studies addressing lumbar degenerative spine disease (LDSD). Sarcopenia could negatively impact the quality of life and postoperative outcomes in several diseases, including cervical spondylotic myelopathy (CSM) and LDSD. However, there was no consensus among the studies regarding the relationship between sarcopenia and pain. These discrepancies were attributed to gaps in the assessment of sarcopenia, which the current study identifies as important challenges. This review identified several problems in the literature, including the limited number of studies examining CSM, adult spinal deformity (ASD) and scoliosis, and the retrospective study design of most reports. The further accumulation of quality research is needed to clarify the relationship between SS and sarcopenia.

Percutaneous ethanolamine oleate sclerotherapy for aggressive vertebral hemangioma: A case report.

Vertebral hemangiomas are the most common benign lesion of the spine which are often an asymptomatic incidental finding. However, a few hemangiomas are aggressive and characterized by bone expansion and extraosseous extension into the paraspinal and epidural spaces. We report the case of a patient presenting an aggressive vertebral hemangioma causing back pain and bilateral numbness of the legs. Among various treatment modalities, a minimally invasive percutaneous sclerotherapy procedure using ethanolamine oleate under computed tomography and fluoroscopic guidance was safely and successfully performed with good clinical outcomes.

Walking speed is associated with postoperative pain catastrophizing in patients with lumbar spinal stenosis: a prospective observational study.

BACKGROUND: The purpose of this study was to investigate whether walking speed is associated with postoperative pain catastrophizing in patients with lumbar spinal stenosis. METHODS: In this prospective observational study, consecutive patients with clinically and radiologically defined lumbar spinal stenosis underwent surgical treatment (decompression, or posterolateral or transforaminal lumbar interbody fusion) at Tottori University Hospital, between October 2015 and April 2018. The pain catastrophizing scale, walking speed, leg and back pain (numerical rating scale), and Japanese Orthopaedic Association score were evaluated preoperatively and at 3, 6, and 12 months postoperatively. Correlations between the pain catastrophizing scale and each variable were analyzed at each evaluation time point. The effect of walking speed on the pain catastrophizing scale was analyzed using mixed-effect models for repeated measurements. RESULTS: Ninety-four patients were included at baseline, and 83, 88, and 82 patients were analyzed at 3, 6, and 12 months postoperatively, respectively. The pain catastrophizing scale was significantly correlated with walking speed, leg pain, back pain, and the Japanese Orthopaedic Association score at all evaluation time points. The pain catastrophizing scale was associated with walking speed at all evaluation time points. CONCLUSIONS: Our results suggest that changes in postoperative pain catastrophizing after lumbar spine surgery are associated with walking speed. Thus, walking speed is a necessary assessment for the management of pain catastrophizing and associated pain and disability in patients after lumbar spine surgery.

Relationship between Facial Color Changes and Psychological Problems Associated with Lower Back Pain.

Background and Objectives: The aim of this study was to determine whether a non-contact sensor that detects complexion changes can be used to assess the psychological state of patients with chronic lower back pain (LBP). Materials and Methods: Twenty-six patients with LBP (LBP group; mean age = 68.0 ± 13.9 years) and 18 control subjects without LBP (control group; mean age = 60.8 ± 16.1 years) were included in the study. All the subjects in the two groups wore headphones when asked LBP-related and LBP-unrelated questions. During questioning, the facial image of the subjects was captured using a video camera, and the complexion of the subjects was converted into red, green, and blue (RGB) values. RGB correlation coefficients (RGBCCs; range: 0-1) represent the difference in complexion between LBP-related and LBP-unrelated questions. A high RGBCC indicates that the brain is more activated by LBP-related questions than by LBP-unrelated questions. We also noted the scores of subjects on the Numerical Rating Scale (NRS), Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Pain Catastrophizing Scale (PCS), and Hospital Anxiety and Depression Scale (HADS). Results: There were no significant differences in RGBCC between the control and LBP groups (0.64 versus 0.56, p = 0.08). In the LBP group, no correlation was observed between RGBCC and each examination item of NRS, JOABPEQ, and HADS. In contrast, a correlation was observed between RGBCC and the rumination subscale of PCS in the LBP group (Spearman's rank correlation coefficient = 0.40, p = 0.04). Conclusions: The complexion of patients with catastrophic thinking changes when the patients are asked LBP-related questions.

Physical Function and Low Back Pain in Leek Farmers: A Comparison with Non-Farmers.

Background: The purpose of this study was to investigate the low back pain (LBP) and physical function of young to middle aged farmers of leeks in western Tottori Prefecture. Methods: Fifteen farmers (55 years old or younger) cultivating leeks in western Tottori Prefecture were recruited as the subjects, and 14 non-farmers matching the age and sex of the subjects were recruited as the control group. A questionnaire survey was conducted to determine the presence or absence of LBP, smoking, and alcohol consumption. Physical functions were measured by anthropometry (body fat percentage and muscle mass), Finger-Floor distance (FFD), back muscle strength, and upper body bending, and lumbar muscle cross-sectional area (CSA) was evaluated by magnetic resonance imaging (MRI). Results: Weight, BMI, body fat percentage, upper body bending, back muscle strength, and L3/4 iliocostalis lumborum CSA, current LBP were significantly higher in the leek farmer group. One-way analysis of variance showed significant differences in upper body bending, and history of LBP. Conclusion: LBP was more common among leek farmers. The characteristics of leek farmers with LBP were history of LBP.

Laparoscopic pelvic lymph node dissection in cadaver surgical training from the combined perspectives of urologists, gastroenterologists and gynecologists improves overall knowledge and technique: initial experience of multidisciplinary cadaver surgical training at a single institution in Japan.

Surgeons in Japan have recently become more familiar with cadaver surgical training (CST). Extended pelvic lymph node dissection (PLND) considering the vesicohypogastric fascia and ureterohypogastric nerve fascia is gradually being performed not only in urology, but also in gynecology and gastroenterology. We performed CST using a 76-year-old female cadaver who was fixed by the Thiel method, with the aim of confirming the differences in the extent of PLND performed by certified laparoscopic specialists in urology, gastroenterology and gynecology. Even in the common surgeries, there are still several areas where anatomical structures are poorly understood. In recent years, with the spread of robotic surgery, the techniques related to PLND in these three departments have gradually become similar. Through this CST program, we were able to understand the differences in procedures and the extent of PLND in these three departments. By continuing these CSTs, we hope that a standardized PLND procedure will be performed not only within the same department, but also between different departments, and that high-quality PLND will be safely performed.

Evaluating the Reproducibility of the Walking Test for Intermittent Claudication Associated with Lumbar Spinal Stenosis.

STUDY DESIGN: This is a multicenter, prospective study. PURPOSE: This study aimed to evaluate the reproducibility of the walking test for patients with lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: Walking test is one of the useful procedures to investigate cauda equina syndrome with lumbar spinal stenosis. One the other hands, there were few studies to investigate the reproducibility of this test. METHODS: In this study, we prospectively examined 70 LSS patients with intermittent claudication symptoms at a multicenter outpatient clinic. A walking test was administered at baseline and week 4 to assess patients' walking distance and lower limb pain and numbness. Immediately after the walking test, patients were asked to use the Visual Analog Scale (VAS) to rate their pain and numbness in the front, back, outside, inside, and hip of the lower legs. The reproducibility of the walking test was evaluated using Cohen's κ analysis and intraclass correlation coefficients (ICCs). Meanwhile, the Swiss Spinal Stenosis (SSS) Questionnaire was used to evaluate the severity of the stenosis. RESULTS: The walking distance ICC at baseline and at week 4 remained unchanged at 0.7, with acceptable interobserver reliabilities for lower limb pain and numbness in both legs. The average VAS score for lower leg pain was 23.2±25.2 mm at baseline and 27.4±28.8 mm at week 4, while the corresponding average VAS score for numbness was 23.4±26.7 mm at baseline and 24.8±25.2 mm at week 4. The ICC score was 0.7 for leg pain and 0.7 for numbness. The mean SSS was 30.2±5.5 at baseline and 29.2±5.2 at week 4, and there was no significant difference in the severity. CONCLUSIONS: The walking test for LSS has acceptable reproducibility.

Evaluation of infections in orthopedic patients using next-generation sequencing.

INTRODUCTION: Culture tests are used to diagnose infections, but there are various problems such as low sensitivity in detecting infections in orthopedic cases. To address this problem, next generation sequencing (NGS) analysis, which can comprehensively search for bacterial genes, is being applied clinically. In this study, we examined whether NGS analysis was useful in evaluating infections in orthopedic cases. METHODS: The participants were 23 patients suspected of having an infection between 2016 and 2017. Samples were collected from tissues suspected of being infected and were subjected to culture tests and NGS analysis, and the positive rates from the culture tests and from the NGS analysis were compared. We also attempted to determine cutoff value for the NGS analysis. RESULTS: A total of 20 cases were ultimately diagnosed as infections and 3 cases were diagnosed as non-infections. The sensitivity of the culture tests was 70%, and the sensitivity of the NGS analysis was 55%. When the NGS analysis was performed with the diversity index set to the cut-off value, the sensitivity was 75% for the Simpson index. In this study, the sensitivity was 90% when the analysis was performed using the NGS index, which is a combination of the diversity index and the OTUs (operational taxonomic units) value. CONCLUSION: NGS analysis using the NGS index showed excellent sensitivity and specificity compared to culture tests. NGS analysis is therefore a useful modality for assessing infections in orthopedic cases.

Bilateral facet effusion is a risk factor for segmental instability with cervical injury without vertebral fracture.

Magnetic resonance imaging (MRI) is effective in identifying cervical spine injury after trauma. However, cervical instability without major bone injury or dislocation is challenging to assess. Hence, the current study aimed to investigate and compare the MRI and radiography findings of segmental instability in patients with cervical spine injury. We investigated 34 participants with cervical spine injury without vertebral fracture. Based on the radiography findings, the participants were categorized into two: group A with segmental instability (n = 11) and group B without segmental instability (n = 23). Both groups were compared in terms of the presence of segmental instability on radiography and MRI. Anterior longitudinal ligament (ALL) injury, disc injury, and bilateral facet effusion were observed in 6/11, 5/11, and 7/11 patients in group A and in 5/23, 2/23 and 7/23 patients in group B, respectively. The results showed significant differences (p < 0.05). Moreover, 2 and 10 of 11 patients in group A and 16 and 7 of 23 patients in group B presented with hemi lateral facet effusion and paravertebral muscle injury, respectively. However, the results did not significantly differ. According to a logistic regression analysis, bilateral facet effusion after trauma was associated with cervical segmental instability (odd ratio: 10.6, 95% confidence interval: 1.31-84.7). Facet joint effusion might be caused by capsule injury during trauma. Most participants with segmental instability had ALL, disc, and flavum injury and bilateral facet effusion. Therefore, we need to consider bilateral facet effusion with other soft tissue damage of the cervical spine as an association factor to show the instability.

Association between preoperative low muscle mass and psychological factors after surgery among patients with lumbar spinal stenosis: A longitudinal study.

It remains controversial whether preoperative low muscle mass affects clinical outcomes after lumbar surgery. Previous studies evaluated outcomes such as pain, quality of life, and disability, but none investigated preoperative low muscle mass and psychological factors. The purpose of this study was to clarify the association between preoperative low muscle mass and postoperative psychological factors in lumbar spinal stenosis (LSS). A longitudinal analysis was performed in 85 consecutive preoperative patients with LSS. Demographic data, leg pain, low back pain, Japanese Orthopaedic Association score, Pain Catastrophizing Scale (PCS) score, Fear-Avoidance Beliefs Questionnaire on Physical Activity (FABQ-PA) score, Hospital Anxiety and Depression Scale (HADS) score, walking velocity, grip strength, and appendicular lean mass were assessed. Muscle mass was measured using bioelectrical impedance analysis. Patients were divided into two groups based on skeletal muscle mass index. These clinical outcomes were evaluated preoperatively and 1 year after surgery. In the 73 patients who were analyzed 1 year after surgery, the prevalence of preoperative low muscle mass was 21.9%. The normal muscle mass group showed significantly improved PCS, FABQ-PA, HADS-anxiety, and HADS-depression scores 1 year after surgery. The low muscle mass group did not demonstrate significantly improved PCS, FABQ-PA, or HADS-depression scores, and had a significantly smaller increase in the FABQ-PA score than the normal muscle mass group. Multivariate analysis showed that low muscle mass was significantly related to change in FABQ-PA score. Our results suggest that preoperative low muscle mass hinders improvement in fear-avoidance beliefs 1 year after surgery.

Preoperative low muscle mass is a predictor of falls within 12 months of surgery in patients with lumbar spinal stenosis.

BACKGROUND: Patients with lumbar spinal stenosis (LSS) may be at high risk of falls due to various factors. No effective fall risk assessments or fall prevention measures have been performed for patients with LSS because only a few studies have evaluated falls in these patients. This study aimed to evaluate the incidence and preoperative predictors of falls within 12 months of surgery in patients with LSS. METHODS: In this prospective study of 82 consecutive preoperative patients with LSS, preoperative demographic data, previous fall history, leg pain, low back pain, Japanese Orthopaedic Association (JOA) score, Hospital Anxiety and Depression Scale (HADS) scores, lower extremity muscle strength, walking speed, grip strength, and muscle mass were assessed at baseline. Falls were assessed at 3, 6, 9, and 12 months after surgery. Participants were categorized as fallers and non-fallers and baseline variables were compared. Binomial logistic regression was used to identify predictors of falls within 12 months of surgery. RESULTS: Seventy-four patients (90.2%) completed the 12-month follow-up after surgery, of whom 24 patients (32.4%) experienced falls. A higher proportion of fallers were female and had a history of falls compared to non-fallers. Fallers had a significantly lower JOA score and a higher HADS-depression score compared to non-fallers. Fallers had significantly lower tibialis anterior muscle strength, gait speed, grip strength, and skeletal muscle mass index. Fallers had a higher prevalence of low muscle mass compared with non-fallers. The presence of low muscle mass was significantly predictive of falls within 12 months of surgery (odds ratio, 4.46; 95% confidence interval, 1.02-19.63). CONCLUSIONS: Patients with LSS have a high incidence of falls after surgery and preoperative low muscle mass may be a predictor of postoperative falls.