The median effective concentration of ropivacaine for ultrasound-guided anterior iliopsoas muscle space block in the elderly undergoing hip surgery: a dose-finding study.

Background: In order to improve perioperative pain and reduce the adverse outcome of severe pain in elderly hip fractures, anterior iliopsoas muscle space block (AIMSB) can be used clinically to reduce pain. The aim of the study is to investigate the 50% effective concentration (EC50) of ropivacaine for ultrasound-guided anterior iliopsoas space block in elderly with hip fracture. Methods: A total of 27 patients were enrolled with aged ≥65 years, American society of Anesthesiologists (ASA) physical status classification II-III and undergoing Total Hip Arthroplasty (THA). We measured the EC50 using Dixon's up-and-down method. Ultrasound-guided AIMSB was performed preoperatively with an initial concentration of 0.2% in the first patient. After a successful or unsuccessful postoperative analgesia, the concentration of local anesthetic was decreased or increased 0.05%, respectively in the next patient. The successful block effect was defined as no sensation to pinprick in the area with femoral nerve, obturator nerve, and lateral femoral cutaneous nerve in 30 min. Meanwhile, the EC50 of ropivacaine was determined by using linear model, linear-logarithmic model, probit regression model, and centered isotonic regression. Results: A total of 12 patients (48%) had a successful block. All patients with a successful block had a postoperative visual analog scale score of <4 in the 12 h. The estimated EC50 values in linear model, linear-logarithmic model, probit regression model, and centered isotonic regression (a nonparametric method) were 0.268%, 0.259%, 0.277%, and 0.289%. The residual standard error of linear model was the smallest (0.1245). Conclusion: The EC50 of ropivacaine in anterior iliopsoas space block under ultrasound guidance is 0.259-0.289%.

Three-dimensional numerical schemes for the segmentation of the psoas muscle in X-ray computed tomography images.

The analysis of the psoas muscle in morphological and functional imaging has proved to be an accurate approach to assess sarcopenia, i.e. a systemic loss of skeletal muscle mass and function that may be correlated to multifactorial etiological aspects. The inclusion of sarcopenia assessment into a radiological workflow would need the implementation of computational pipelines for image processing that guarantee segmentation reliability and a significant degree of automation. The present study utilizes three-dimensional numerical schemes for psoas segmentation in low-dose X-ray computed tomography images. Specifically, here we focused on the level set methodology and compared the performances of two standard approaches, a classical evolution model and a three-dimension geodesic model, with the performances of an original first-order modification of this latter one. The results of this analysis show that these gradient-based schemes guarantee reliability with respect to manual segmentation and that the first-order scheme requires a computational burden that is significantly smaller than the one needed by the second-order approach.

Quantification of muscle recovery in post-ICU patients admitted for acute pancreatitis: a longitudinal single-center study.

OBJECTIVES: Critically ill patients with severe pancreatitis exhibit substantial muscle wasting, which limits in-hospital and post-hospital outcomes. Survivors of critical illness undergo extensive recovery processes. Previous studies have explored pancreatic function, quality of life, and costs post-hospitalization for AP patients, but none have comprehensively quantified muscle loss and recovery post-discharge. By applying an AI-based automated segmentation tool, we aimed to quantify muscle mass recovery in ICU patients after discharge. MATERIALS: Muscle segmentation was performed on 22 patients, with a minimum of three measurements taken during hospitalization and one clinically indicated examination after hospital discharge. Changes in psoas muscle area (PMA) between admission, discharge and follow up were calculated. T-Test was performed to identify significant differences between patients able and not able to recover their muscle mass. RESULTS: Monitoring PMA shows muscle loss during and gain after hospitalization: The mean PMA at the first scan before or at ICU admission (TP1) was 17.08 cm², at the last scan before discharge (TP2), mean PMA was 9.61 cm². The percentage change in PMA between TP1 and TP2 ranged from - 85.42% to -2.89%, with a mean change of -40.18%. The maximum muscle decay observed during the stay was - 50.61%. After a mean follow-up period of 438.73 days most patients (81%) were able to increase their muscle mass. Compared to muscle status at TP1, only 27% of patients exhibited full recovery, with the majority still presenting a deficit of 31.96%. CONCLUSION: Muscle recovery in ICU patients suffering from severe AP is highly variable, with only about one third of patients recovering to their initial physical status. Opportunistic screening of post-ICU patient recovery using clinically indicated imaging and AI-based segmentation tools enables precise quantification of patients' muscle status and can be employed to identify individuals who fail to recover and would benefit from secondary rehabilitation. Understanding the dynamics of muscle atrophy may improve prognosis and support personalized patient care.

Association between cup fixation screw and iliopsoas impingement after total hip arthroplasty.

BACKGROUND: Iliopsoas impingement after total hip arthroplasty can result not only from acetabular cup but also from cup fixation screw. However, research addressing this screw impingement is scarce, leaving the details undetermined. This study aimed to elucidate the incidence and threshold of symptomatic iliopsoas impingement attributable to protrusion of the cup fixation screw into the iliopsoas muscle and to evaluate its impact on postoperative radiographic imaging findings and patient-reported outcome measures. METHODS: A total of 152 hips were included in this study. The symptomatic threshold of screw protrusion was determined using a receiver operating characteristic curve, and patients were divided into low-protrusion and high-protrusion groups using this threshold. The area and Hounsfield Unit values of the iliopsoas muscle on CT and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire postoperatively were investigated. FINDINGS: 10 hips (6.5%) were exhibited symptoms of IPI in this series. The threshold for screw protrusion length was identified as 6.4 mm. Patients in the high protrusion group exhibited significantly larger area and lower Hounsfield Unit values of the iliopsoas muscle. In addition, the high protrusion group revealed significantly lower scores (total, pain, movement, mental). Furthermore, subscales scores (pain, movement) in the high protrusion group didn't improve from 3 months to 12 months postoperatively with significance. INTERPRETATION: This study underscores the imperative for surgeons to consider the length of the cup fixation screw. This careful consideration is crucial for mitigating the incidence of postoperative iliopsoas impingement and enhancing total hip arthroplasty outcomes.

Low psoas muscle index has a negative impact on survival after minimal invasive esophagectomy for cancer in European men.

INTRODUCTION: Sarcopenia, a key component of frailty in cancer patients, is associated with complicated procedures and worse survival after esophageal resection. The psoas muscle index (PMI) has been implicated as a possible sarcopenia imaging marker. This retrospective study aims to elucidate the effect of PMI and BMI in a cohort in Europe after totally minimally invasive esophagectomy for cancer. METHODS: The study included 318 consecutive adult patients (261 men and 57 women) who underwent minimally invasive esophagectomy for cancer between January 2016 and April 2021 in a German University Hospital. The PMI was measured at the third lumbar vertebra in the preoperative CT scan. The endpoints postoperative complication rates and survival rates were analysed and correlated with PMI and BMI according to gender. RESULTS: Male patients with low PMI (< 5.3 cm2/ m2) had a significantly higher rate of postoperative pulmonary and cardiac complications (p = 0.016, respectively p = 0.018). Low PMI and low BMI (<25 kg/m2) were associated with decreased survival rates in the univariate (p < 0.001) and multivariate analysis in male patients (p = 0.024, respectively 0.004). Having a low PMI (< 5.3 cm2/ m2) was significantly associated with worse overall survival in normal and underweight men (p < 0.001), but not in obese men with a BMI ≥ 25kg/m2 (p = 0.476). CONCLUSION: Preoperative PMI and BMI are valid risk factors regarding postoperative survival after minimal invasive esophagectomy for cancer especially in a male European cohort.

Psoas attenuation is associated with early postoperative complications in geriatric patients undergoing multilevel lumbar fusion surgery for degenerative lumbar spinal stenosis.

BACKGROUND: Morphometric analysis of the psoas major muscle has shown utility in predicting postoperative morbidity in various surgical fields, but its usefulness in predicting complications in elderly patients undergoing multilevel lumbar fusion surgery has not been studied. The study aimed to investigate if psoas major parameters are independent risk factors of early postoperative complication among elderly patients. METHODS: Patients who underwent multilevel lumbar fusion for degenerative lumbar spinal stenosis (DLSS) were included. The psoas major was measured at the lumbar 3/4 intervertebral disc level in three ways on computed tomography image: psoas muscle mass index, mean muscle attenuation, and morphologic change of the psoas major. Early complications were graded using the Clavien-Dindo classification system and the Comprehensive complication index (CCI). A CCI ≥ 26.2 indicated severe complications. Logistic regression was performed to identify independent risk factors. RESULTS: This retrospective study reviewed 108 patients (mean age 70.9 years, female to male ratio 1.8:1). Complications were observed in 72.2% of patients, with allogeneic blood transfusion being the most frequent (66.7%), followed by wound infection, acute heart failure (2.8% each). Severe complications occurred in 13.9% of patients. After multivariable regression analysis, those in the lowest psoas muscle attenuation tertile had higher odds of experiencing early postoperative complications (OR: 3.327, 95% CI 1.134-9.763, p = 0.029) and severe complications (OR: 6.964, 95% CI 1.928-25.160, p = 0.003). CONCLUSION: The psoas muscle attenuation can be used as a predictor of early postoperative complications in elderly patients undergoing multilevel lumbar fusion surgery for DLSS.

Myositis Ossificans of the Psoas Major Muscle After XLIF With Preoperative Administration of Romosozumab: A Case Report.

CASE: A 62-year-old woman receiving romosozumab for 3 months underwent extreme lateral interbody fusion (XLIF) for lumbar degenerative spondylolisthesis. From 1 week after surgery, she experienced gradually increasing pain from the right groin to the front of the thigh. Examination revealed ossifying myositis in bilateral psoas major muscles. Etidronate treatment was initiated, improving pain after 4 days. Computed tomography showed lesion disappearance by 3 months after surgery. CONCLUSION: We report a rare case of myositis ossificans in bilateral psoas major muscles following XLIF surgery, possibly influenced by intraoperative manipulation and romosozumab treatment. Etidronate administration may be effective, as with heterotopic ossification.

Assessment of Psoas Muscle Index in Middle-Aged Type 2 Diabetes Patients: Impact of Insulin Therapy on Sarcopenia.

OBJECTIVE: Sarcopenia, characterized by progressive skeletal muscle loss, poses significant health risks, including physical impairment and mortality. The relationship between sarcopenia and insulin resistance suggests insulin therapy's potential in preserving muscle mass, particularly in Type 2 diabetes mellitus (T2DM) patients. This study aims to evaluate the Psoas Muscle Index (PMI) via computed tomography (CT) in middle-aged T2DM patients on insulin therapy versus oral antidiabetic drugs (OAD) and controls. METHODS: This retrospective study included 107 middle-aged T2DM patients undergoing non-contrast CT scans and 58 age-matched controls. CT images were analyzed to calculate PMI. Statistical analysis included Chi-square tests, independent samples t-tests, Mann-Whitney U tests, and correlation analyses. RESULTS: Insulin-treated patients exhibited higher PMI than OAD users (p < 0.001), while OAD users had lower PMI than controls (p < 0.001). No significant difference was found between insulin-treated patients and controls (p = 0.616). Negative correlations were observed between T2DM duration/age and PMI across all groups, with a positive correlation between T2DM duration and BMI observed in the OAD group. CONCLUSIONS: Insulin therapy in T2DM patients, regardless of age or disease duration, positively impacts muscle mass, highlighting its potential in preserving muscular health and advocating for tailored treatment strategies in T2DM management.

Incidental discovery of unilateral hydronephrosis unveiling psoas major desmoid-type fibromatosis in a 24-year-old male: A case report with a 5-year follow-up.

RATIONALE: Desmoid-type fibromatosis (DTF), also known as aggressive fibromatosis, is a rare neoplasm originating from the fascial or musculoaponeurotic tissues. While benign and characterized by slow growth, it exhibits local aggressiveness and lacks specific clinical characteristics. However, in a considerable percentage of patients, it could be asymptomatic and discovered by accident during routine clinical examinations. Only a few cases of DTF arising from the psoas major muscle have been reported in the medical literature. PATIENT CONCERNS: A 24-year-old male, asymptomatic and without significant personal or family medical history, was diagnosed with grade 2 hydronephrosis by abdominal ultrasonography during a routine physical examination. This diagnosis was made 15 days after undergoing uncomplicated open-heart surgery to repair an atrial septal defect. DIAGNOSIS: Intravenous pyelogram revealed hydronephrosis with dilation of the pelvicalyceal system. Ureteroscopy ruled out any intrinsic lesions of the ureter. Contrast-enhanced computed tomography identified a 3.5 × 2 × 5.2 cm mass in the retroperitoneum, closely associated with the psoas muscle and enveloping the ureter adjacent to the iliac artery. Postoperative pathological analysis confirmed a definitive diagnosis of sporadic DTF. INTERVENTIONS: The patient underwent exploratory abdominal surgery, during which the tumor was resected without any intraoperative complications. RESULTS: After close monitoring over a 5-year follow-up period, which included periodic physical examinations, magnetic resonance imaging, and ultrasonography, no local recurrence was detected. LESSONS: Achieving an accurate preoperative diagnosis presents a challenge in cases involving retroperitoneal tumors originating from the psoas major muscle and encasing the ureter. However, the insertion of a double J stent is deemed a crucial step in the surgical process, facilitating the dissection and isolation of the ureter from the tumor while preserving kidney function.

[Radiographic parameters and influencing factors of paraspinal muscle degeneration in healthy people].

Objective: To measure the paraspinal muscle parameters, explore the characteristics of paraspinal muscles, and investigate the influence factors of paraspinal muscle degeneration in healthy people. Methods: Eighty-two healthy Chinese people were prospectively recruited between February 2020 and November 2020, including 36 males and 46 females. The age ranged from 21 to 75 years, with a mean of 48.0 years. The height ranged from 150 to 183 cm, with a mean of 165.6 cm. The body mass ranged from 43 to 100 kg, with a mean of 65.4 kg. The body mass index (BMI) ranged from 16.7 to 32.4 kg/m 2, with a mean of 23.7 kg/m 2. Parameters of the paraspinal muscles (multifidus muscle, erector spinae muscle, and psoas major muscle) at L 3, L 4, and L 5 levels were measured by MRI, including the relative total cross-sectional area (rtCSA), relative fatty cross-sectional area (rfCSA), relative signal intensity (rSI), and fatty infiltration (FI). The differences of paraspinal muscle parameters at different genders and different measurement levels were compared; Pearson or Spearman correlation analysis was used to explore the relationship between paraspinal muscle parameters and age, height, body mass, BMI. Results: From L 3 to L 5 level, the rtCSA and rfCSA of multifidus muscle and psoas major muscle as well as the rfCSA of erector spinae muscle increased, while rtCSA of erector spinae muscle decreased. The FI and rSI of paraspinal muscles increased gradually. The parameters of paraspinal muscles at L 4 and L 5 levels were significantly different from those at L 3 levels ( P<0.05). There were significant differences in rtCSA and rfCSA of multifidus muscle, rtCSA, FI, and rSI of erector spinae muscle as well as rtCSA, rfCSA, and FI of psoas major muscle between L 4 and L 5 levels ( P<0.05). Compared with males, the rfCSA and FI of multifidus muscle, FI of erector spinae muscle, and FI of psoas major muscle were significantly higher in females, while the rtCSA of psoas major muscle was significantly lower ( P<0.05). Age was significantly negatively correlated with rtCSA of paraspinal muscles ( P<0.05), but significantly positively correlated with FI of paraspinal muscles, rfCSA and rSI of multifidus and erector spinae muscles ( P<0.05). Height was significantly negatively correlated with rfCSA and FI of paraspinal muscles ( P<0.05). Conclusion: The degree of paraspinal muscle degeneration increases gradually along the spine axis from head to tail. Paraspinal muscle degeneration is related to age, height, and gender. The relationship between the body mass, BMI and paraspinal muscle degeneration needs further study.

The role of CT-assessed sarcopenia and visceral adipose tissue in predicting long-term survival in patients undergoing elective endovascular infrarenal aortic repair.

OBJECTIVES: To evaluate if ileo-psoas muscle size and visceral adipose tissue (VAT) can predict long-term survival after endovascular aneurysm repair (EVAR). METHODS: Patients who underwent EVAR between 2004 and 2012 in a single centre were included. Total psoas muscle area (TPA), abdominal VAT area, subcutaneous adipose tissue (SAT), and total adipose tissue were measured on the preoperative CT. Primary endpoint was all-cause mortality. Values are presented as median and interquartile range or absolute number and percentage. Cox regression analyses were performed to assess the associations with mortality. RESULTS: Two hundred and eighty-four patients could be included in the study. During a median follow-up of 8 (4-11) years, 223 (79.9%) patients died. Age (P ≤ .001), cardiovascular (P = .041), cerebrovascular (P = .009), renal diseases (P = .002), and chronic obstructive pulmonary disease (P ≤ .001) were independently associated with mortality. TPA was associated with mortality in a univariate (P = .040), but not in a multivariate regression model (P = .764). No significant association was found between mortality and TPA index (P = .103) or any of the adiposity measurements with the exception of SAT (P = .040). However, SAT area loss in a multivariate analysis (P = .875). CONCLUSIONS: Assessment of core muscle size and VAT did not contribute to improving the prediction of long-term survival after EVAR. ADVANCES IN KNOWLEDGE: The finding of this study contradicts the previously claimed utility of core muscle size and VAT in predicting long-term survival after EVAR.

Evaluation of Sarcopenia by Psoas Muscle Measurements in Osteoporotic Patients with Vertebral Compression Fracture.

OBJECTIVE: To examine the effect of sarcopenia on osteoporotic vertebral compression fracture with psoas muscle measurements. STUDY DESIGN: Cross-sectional study. Place and Duration of the Study: Department of Radiology, Sivas Cumhuriyet University, Sivas, Turkiye, from January 2020 to March 2023. METHODOLOGY: Measurements evaluating psoas muscle area (PMA), psoas muscle index (PMI), and psoas muscle density (PMD) were made at L2 vertebral corpus level for the diagnosis of sarcopenia from muscle mass with computed tomography (CT). The association between sarcopenia and osteoporotic compression fracture was examined with significance at p <0.05. RESULTS: Osteoporotic patients with 37 compression fractures and 37 without compression fractures were examined. PMA and PMI were statistically significantly lower in the study group (p <0.01). PMD was also found to be statistically significantly lower in the study group (p <0.05). Diagnostic performance (DP) was good for the discrimination of patients and control groups for psoas area (AUC = 0.88; 95% confidence interval (CI) 0.807 - 0.956 and PMI (AUC = 0.83; 95% CI 0.734 - 0.917. It was poor for psoas density (AUC = 0.66, 95% CI 0.531 - 0.782). CONCLUSION: Sarcopenia is an important risk factor for osteoporotic compression fracture. Psoas measurements show a significant association with osteoporosis and vertebral fracture and can be easily determined on CT scan. KEY WORDS: Sarcopenia, Osteoporotic compression fracture, Psoas muscle.

Management of intramuscular melanoma metastases to the psoas.

We detail a case of a woman in her 40s with isolated melanoma skeletal muscle metastasis (MSMM) to the right psoas muscle. This patient underwent R0 surgical resection through a novel pelvic approach. She received subsequent adjuvant immunotherapy with Braftovi/Mektov along with adjuvant radiation. She is currently disease free at 9 months post surgery. Here, we describe our novel surgical approach including description of the tumour pathology. We explain our multidisciplinary management of MSMM consisting of a multidisciplinary surgical approach by surgical oncology, gynecological oncology and urology as well as multidisciplinary medical management by oncology, radiation oncology and pathology. Finally, we discuss best current options for therapeutic management.

Preoperative risk factors for skeletal muscle mass loss in patients with biliary tract cancer.

BACKGROUND: Endoscopic retrograde cholangiography (ERC)-related procedures, usually performed before biliary tract cancer (BTC) surgery, are associated with increased risk for various complications, which can cause sarcopenia. No study has previously elucidated the relationship between preoperative ERC-related procedures and sarcopenia/skeletal muscle mass loss. METHODS: Patients with BTC who underwent radical surgical resection following ERC-related procedures were included. Skeletal muscle mass was evaluated using the psoas muscle mass index (PMI), which was determined using computed tomography images, and the change in PMI before the initial pre-ERC and surgery (ΔPMI) was calculated. Risk factors for advanced skeletal muscle mass loss, defined as a large ΔPMI, were evaluated. RESULTS: The study cohort included 90 patients with a median age of 72 (interquartile range, 65-75) years. The median PMI pre-ERC and surgery was 4.40 and 4.15 cm2/m2, respectively (p < .01). The median ΔPMI was -6.2% (interquartile range, -10.9% to 0.5%). By multivariate analysis, post-ERC pancreatitis and cholangitis before surgery were independent predictive factors for large PMI loss (odds ratio, 4.57 and 3.18, respectively; p = .03 and p = .02, respectively). CONCLUSIONS: Skeletal muscle mass decreases preoperatively in most patients with BTC undergoing ERC. Post-ERC pancreatitis and cholangitis before surgery were independent risk factors for large skeletal muscle mass loss.

Use of 3D-CT-derived psoas major muscle volume in defining sarcopenia in colorectal cancer.

BACKGROUND: Sarcopenia is characterized by reduced skeletal muscle volume and is a condition that is prevalent among elderly patients and associated with poor prognosis as a comorbidity in malignancies. Given the aging population over 80 years old in Japan, an understanding of malignancies, including colorectal cancer (CRC), complicated by sarcopenia is increasingly important. Therefore, the focus of this study is on a novel and practical diagnostic approach of assessment of psoas major muscle volume (PV) using 3-dimensional computed tomography (3D-CT) in diagnosis of sarcopenia in patients with CRC. METHODS: The subjects were 150 patients aged ≥ 80 years with CRC who underwent primary tumor resection at Juntendo University Hospital between 2004 and 2017. 3D-CT measurement of PV and conventional CT measurement of the psoas major muscle cross-sectional area (PA) were used to identify sarcopenia (group S) and non-sarcopenia (group nS) cases. Clinicopathological characteristics, operative results, postoperative complications, and prognosis were compared between these groups. RESULTS: The S:nS ratios were 15:135 for the PV method and 52:98 for the PA method. There was a strong positive correlation (r = 0.66, p < 0.01) between PVI (psoas major muscle volume index) and PAI (psoas major muscle cross-sectional area index), which were calculated by dividing PV or PA by the square of height. Surgical results and postoperative complications did not differ significantly in the S and nS groups defined using each method. Overall survival was worse in group S compared to group nS identified by PV (p < 0.01), but not significantly different in groups S and nS identified by PA (p = 0.77). A Cox proportional hazards model for OS identified group S by PV as an independent predictor of a poor prognosis (p < 0.05), whereas group S by PA was not a predictor of prognosis (p = 0.60). CONCLUSIONS: The PV method for identifying sarcopenia in elderly patients with CRC is more practical and sensitive for prediction of a poor prognosis compared to the conventional method.

Clinical and radiographic outcomes following 120 consecutive patients undergoing prone transpsoas lateral lumbar interbody fusion.

PURPOSE: The prone transpsoas approach is a single-position alternative to traditional lateral lumbar interbody fusion (LLIF). Earlier prone LLIF studies have focused on technique, feasibility, perioperative efficiencies, and immediate postoperative radiographic alignment. This study was undertaken to report longer-term clinical and radiographic outcomes, and to identify learnings from experiential evolution of the prone LLIF procedure. METHODS: All consecutive patients undergoing prone LLIF for any indication at one institution were included (n = 120). Demographic, diagnostic, treatment, and outcomes data were captured via prospective institutional registry. Retrospective analysis identified 31 'pre-proceduralization' and 89 'post-proceduralization' prone LLIF approaches, enabling comparison across early and later cohorts. RESULTS: 187 instrumented LLIF levels were performed. Operative time, retraction time, LLIF blood loss, and hospital stay averaged 150 min, 17 min, 50 ml, and 2.2 days, respectively. 79% of cases were without complication. Postoperative hip flexion weakness was identified in 14%, transient lower extremity weakness in 12%, and sensory deficits in 10%. At last follow-up, back pain, worst-leg pain, Oswestry, and EQ-5D health state improved by 55%, 46%, 48%, and 51%, respectively. 99% improved or maintained sagittal alignment with an average 6.5° segmental lordosis gain at LLIF levels. Only intra-psoas retraction time differed between pre- and post-proceduralization; proceduralization saved an average 3.4 min/level (p = 0.0371). CONCLUSIONS: The largest single-center prone LLIF experience with the longest follow-up to-date shows that it results in few complications, quick recovery, improvements in pain and function, high patient satisfaction, and improved sagittal alignment at an average one year and up to four years postoperatively.

Effect of psoas muscle index on early postoperative outcomes in surgically treated spinal tumours in an Asian population.

BACKGROUND: Sarcopenia has been purported to be a pre-operative risk factor that affects patient outcomes in oncological surgery, but no study as of yet has investigated the effect of sarcopenia in patients with spinal tumours. Psoas muscle measurements, including the psoas muscle index (PMI), are an objective way to determine sarcopenia. OBJECTIVES: We investigated if PMI could predict post-operative outcomes (length of hospital stay and post-operative complications) in surgically treated spinal tumour patients in a multi-ethnic Asian population. METHODS: We conducted a retrospective cohort study of patients with spinal tumours who underwent surgery at our tertiary institution from January 2016 to January 2020. PMI was measured on T2-weighted MRI sequences, at the middle of the L3 vertebral body and measurements were collected by 2 independent raters. The primary outcome was length of hospital stay (LOS), and the secondary outcome was post-operative complications. ROC curve was used to attain the cut-off value for PMI and the population was then stratified into 2 groups; sarcopenic if PMI was less than 1.22 and non-sarcopenic if the PMI value was more than or equal to 1.22. Multivariable linear regression was used for LOS, while multivariate logistic regression was used for complications. RESULTS: 57 patients were included with a mean length of stay of 17.8 days (SD 25.1) and the total number of patients with complications were 20 (35.1 %). Mean LOS was significantly higher in the sarcopenic group compared to the non-sarcopenic group. Univariate analysis confirmed the association of lower psoas muscle index corresponding with longer lengths of stay and this was corroborated in a multivariable linear regression model. There were no significant associations between PMI and postoperative complications. CONCLUSIONS: Lower PMI values were significantly associated with a longer LOS. PMI may be warranted for risk stratifying Asian spinal tumour patients undergoing surgery.

Association of magnetic resonance imaging-derived sarcopenia with outcomes of patients with hepatocellular carcinoma after hepatectomy.

PURPOSE: To evaluate whether sarcopenia, diagnosed by magnetic resonance imaging (MRI) protocol, constitutes a prognosis-associated risk factor in patients with hepatocellular carcinoma (HCC) after hepatectomy. METHODS: One hundred and ninety-three patients who underwent hepatectomy for HCC were retrospectively enrolled. The areas of the total skeletal muscle (SM) and psoas muscle (PM) were evaluated at the third lumbar vertebra in the preoperative MR images, and divided by the square of height in order to obtain the skeletal muscle index (SMI) and psoas muscle mass index (PMI). Sarcopenia was diagnosed respectively on the definitions based on the SMI or PMI. The potential of muscle-defined sarcopenia as a prognostic factor for overall survival (OS) and recurrence-free survival (RFS) was investigated in these patients. RESULTS: The areas of SM and PM, and SMI and PMI were significantly higher in the men than in the women (all p < 0.05). Notably, SMI-defined sarcopenia displayed a significant sex difference (p = 0.003), while PMI-defined sarcopenia did not (p = 0.370). Through univariate and multivariate analyses, PMI-defined sarcopenia remained an independent predictor for OS and RFS (HR = 3.486, 95% CI: 1.700-7.145, p = 0.001 and HR = 1.993, 95% CI: 1.246-3.186, p = 0.004), even after adjusting for other clinical variables. Moreover, Kaplan-Meier analysis demonstrated significantly poorer OS and RFS for patients with sarcopenia defined by using PMI, but not SMI, compared to those without sarcopenia (p < 0.001 and p = 0.006, respectively). CONCLUSION: MRI-derived, sarcopenia defined by using PMI, not SMI, may serve as a significant risk factor for RFS and OS in patients with HCC after hepatectomy.

Are trunk muscle sizes different between acute lumbar spondylolysis and nonspecific low back pain?

INTRODUCTION: Morphological differences in the trunk muscles between adolescent athletes with lumbar spondylolysis (LS) and nonspecific low back pain (NSLBP) have not been fully elucidated. This study aimed to investigate the differences in physiological cross-sectional areas (CSA) of the trunk muscles between athletes with acute LS and those with acute NSLBP. METHODS: Magnetic resonance images of 48 patients aged 13-14 years diagnosed with acute LS or NSLBP were retrospectively evaluated. The CSA of the paraspinal, psoas major, and rectus abdominis muscles at the L4-5 intervertebral disc level were measured. RESULTS: CSA of the left and right paraspinal muscles in the acute LS group were significantly larger than those in the acute NSLBP group (left: mean difference, 276.0 mm2; 95% confidence interval [CI], 68.5-483.6 mm2; P = 0.01; right: mean difference, 228.8 mm2; 95% CI, 7.6-450.1 mm2; P = 0.04). The ratio between the left paraspinal muscles and left psoas major in the acute LS group was significantly larger than that in the acute NSLBP group (mean difference, 0.2; 95% CI, 0.0-0.4; P = 0.03). CONCLUSIONS: Trunk muscle size may differ between adolescent athletes with acute LS and those with NSLBP. Future research involving healthy controls is required to better understand the morphological characteristics of these injuries.

Lower psoas mass indicates worse prognosis in percutaneous vertebroplasty-treated osteoporotic vertebral compression fracture.

The correlation between lower psoas mass and the prognosis of osteoporotic vertebral compression fractures (OVCF) is still unclear. This study aims to investigate the impact of lower psoas mass on the prognosis of patients undergoing percutaneous vertebroplasty (PVP). One hundred and sixty-three elderly patients who underwent single-segment PVP from January 2018 to December 2021 were included. The psoas to L4 vertebral index (PLVI) via MRI were measured to assess psoas mass. Patients were divided into high PLVI (> 0.79) and low PLVI (≤ 0.79) groups based on the median PLVI in the cohort. The basic information (age, gender, body mass index (BMI) and bone mineral density (BMD)), surgical intervention-related elements (duration of operation, latency to ambulation, period of hospital stay, and surgical site), postoperative clinical outcomes (Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, Japanese Orthopaedic Association (JOA) scores), and incidence of secondary fractures) were compared. Patients showed no statistically significant differences in terms of age, gender, surgical sute, BMI, BMD and preoperative VAS, ODI, JOA scores (P > 0.05) between the two groups. However, there were significant differences in terms of latency to ambulation, period of hospital stay (P < 0.05). VAS, ODI, and JOA scores at 1, 6, and 12 months after surgery showed that the high PLVI group had significantly better outcomes than the low PLVI group (P < 0.05). Additionally, the low PLVI group had a significantly higher incidence of recurrent fracture (P < 0.05). Lower psoas mass can reduce the clinical effect of PVP in patients with osteoporotic vertebral compression fractures, and is a risk factor for recurrent vertebral fracture.