Frequency and Characteristics of Overestimated Renal Function in Japanese Patients with Chronic Liver Disease and Its Relation to Sarcopenia.

Renal dysfunction and sarcopenia are important prognostic factors in patients with chronic liver disease (CLD). Muscle atrophy can cause the overestimation of renal function based on serum creatinine. However, the frequency of overestimated renal function in Japanese patients with CLD and its relationship with sarcopenia are unclear. In present study, we evaluated the frequency of overestimated renal function, defined as a >20% higher eGFR using creatinine than using cystatin C, in 307 patients with CLD as well as its relationship with indicators of sarcopenia. In total, 24.8% of patients had overestimated renal function. In a multivariate regression analysis, liver cirrhosis (p = 0.004) and psoas muscle mass index (p = 0.049) were significantly associated with overestimated renal function. Loss of skeletal muscle mass was significantly more frequent in both male and female patients with overestimated renal function than without. In males, the loss of muscle strength and rate of sarcopenia, defined as loss of muscle mass and strength, were significantly higher in patients with than without overestimated renal function. The high frequency of overestimated renal function in Japanese patients suggests that indicators of renal function should be carefully considered; furthermore, monitoring and interventions for both renal function and sarcopenia are needed in patients with CLD.

Radiographs assessment of changes in the psoas muscle at L4-L5 level after single-level lateral lumbar interbody fusion in patients with postoperative motor weakness.

The purposes of this study were (1) to investigate postoperative changes in cross-sectional area (CSA) and signal intensity (SI) of the psoas muscle (PS) using magnetic resonance imaging (MRI) and (2) to compare the CSA and SI of the PS between patients with and without motor weakness after single-level lateral lumbar interbody fusion (LLIF) at level L4-L5. Sixty patients were divided into two groups-those with postoperative motor weakness and those without-and the two groups were compared. Baseline demographics and clinical characteristics, such as operation time and blood loss, length of hospital stay, and postoperative complications, were recorded. The CSA and SI of the PS were obtained from the MRI regions of interest defined by manual tracing. Patients who developed motor weakness after surgery were significantly older (p = 0.040). The operation time (p = 0.868), LLIF operative time (p = 0.476), and estimated bleeding loss (p = 0.168) did not differ significantly between groups. In both groups, the CSA and SI of the left and right PS increased after surgery. The change in the CSA of the left PS was significantly higher in patients with weakness (247.6 ± 155.2 mm2) than without weakness (152.2 ± 133.1 mm2) (p = 0.036). The change in SI of the left PS did not differ between the two groups (p = 0.530). To prevent postoperative motor weakness regardless of the operation time, surgeons should be aware of the potential for surgical invasive of the PS during LLIF in older people.

The prognostic significance of combined geriatric nutritional risk index and psoas muscle volume in older patients with pancreatic cancer.

BACKGROUND: The geriatric nutritional risk index (GNRI), originally developed as a nutritional assessment tool to evaluate mortality and morbidity in older hospitalized patients (i.e., those aged ≥65 years), is regarded as a prognostic factor in several cancers. Body composition is also an important consideration when predicting the prognosis of patients with cancer. This study aimed to investigate the relationship between the GNRI and psoas muscle volume (PMV) for survival outcomes in patients with pancreatic cancer. METHODS: This retrospective study evaluated the prognostic significance of the GNRI and PMV in 105 consecutive patients aged ≥65 years who underwent pancreatectomy for histologically confirmed pancreatic cancer. The patients were divided into high (GNRI > 98) and low GNRI groups (GNRI ≤98), and into high (PMV > 61.5 mm3/m3 for men and 44.1 mm3/m3 for women) and low PMV (PMV ≤ 61.5 mm3/m3 for men and 44.1 mm3/m3 for women) groups. RESULTS: Both the 5-year overall survival (OS) and recurrence-free survival (RFS) rates were significantly greater among patients in the high GNRI group than among patients in the low GNRI group. Similarly, both the 5-year OS and RFS rates were significantly greater among patients in the high PMV group than among patients in the low PMV group. Patients were stratified into three groups: those with both high GNRI and high PMV; those with either high GNRI or high PMV (but not both); and those with both low GNRI and low PMV. Patients with both low GNRI and low PMV had a worse 5-year OS rate, compared with patients in other groups (P <  0.001). The C-index of the combination of the GNRI and PMV for predicting 5-year OS was greater than the C-indices of either the GNRI or PMV alone. Multivariate analysis revealed that the combination of the GNRI and PMV was an independent prognostic factor in patients aged ≥65 years with pancreatic cancer (P = 0.003). CONCLUSIONS: The combination of the GNRI and PMV might be useful to predict prognosis in patients aged ≥65 years with pancreatic cancer.

Low skeletal muscle density combined with muscle dysfunction predicts adverse events after adult cardiovascular surgery.

BACKGROUND AND AIMS: Although muscle dysfunctions are widely known as a poor prognostic factor in patients with cardiovascular disease, no study has examined whether the addition of low skeletal muscle density (SMD) assessed by computed tomography (CT) to muscle dysfunctions is useful. This study examined whether SMDs can strengthen the predictive ability of muscle dysfunctions for adverse events in patients who underwent cardiovascular surgery. METHODS AND RESULTS: We retrospectively reviewed 853 patients aged ≥40 years who had preoperative CT for risk management purposes and who measured muscle dysfunctions (weakness: low grip strength and slowness: slow gait speed). Low SMD based on transverse abdominal CT images was defined as a mean Hounsfield unit of the psoas muscle <45. All definitions of muscle dysfunction (weakness only, slowness only, weakness or slowness, weakness and slowness), the addition of SMDs was shown to significantly improve the continuous net reclassification improvement and integrated discrimination improvement for adverse events in all analyses (p < 0.05). Low SMDs combined with each definition of muscle dysfunction had the highest risk of all-cause death (hazard ratio: lowest 3.666 to highest 6.002), and patients with neither low SMDs nor muscle dysfunction had the lowest risk of all-cause and cardiovascular-related events. CONCLUSION: The addition of SMDs consistently increased the predictive ability of muscle dysfunctions for adverse events. Our results suggest that when CT is performed for any clinical investigation, the addition of the organic assessment of skeletal muscle can strengthen the diagnostic accuracy of muscle wasting.

Is sarcopenia really a risk factor in the development of postoperative complications?

PURPOSE: This study was aimed to evaluate the impact of sarcopenia, which was defined by total psoas area (TPA) and total psoas volume (TPV) measurements, on the development of major postoperative complications. MATERIAL-METHODS: Sarcopenia was assessed in 225 patients with gastrointestinal cancer who underwent surgery between October 2015 and March 2020. The impact of sarcopenia defined by TPA and TPV on major postoperative complications was assessed using multivariate analysis. RESULTS: Both the median TPA and TPV were higher in men than that in women (p < 0.001). The cut-off value of TPA to define sarcopenia was 526.5 mm2/m2 and 495.68 mm2/m2 for men and women, respectively, and the cut-off value of TPV was 79.6 cm3/m2 for men and 83.1 cm3/m2 for women, While 102 patients (45.3%) had sarcopenia defined by TPA, 54 (24%) had sarcopenia defined by TPV. Seventy-eight patients had at least one complication; 36 (46%) had major complications, and 15 patients died during the study. In logistic regression analysis, only sex was found as a risk factor for the development of sarcopenia (OR = 13.403, p = 0.014). There was a positive correlation between TPA and TPV in male and female patients separately (r = 0.841 and r = 0.883, respectively, p < 0.001). Only sarcopenia defined by TPV was found as a risk factor for the development of major postoperative complication (OR: 35.349, p = 0.028). CONCLUSION: Sarcopenia defined by TPV is an independent risk factor in predicting major postoperative complications, not TPA. We believe that volume measurement instead of area is a more accurate method for evaluating sarcopenia in gastrointestinal cancer surgery.

Looking beyond the eyeball test: A novel vitality index to predict recovery after esophagectomy.

OBJECTIVES: To (1) measure 4 physiologic metrics before esophagectomy, (2) use these in an index to predict composite postoperative outcome after esophagectomy, and (3) compare predictive accuracy of this index to that of the Fried Frailty Index and Modified Frailty Index. METHODS: Grip strength (kilograms), 30-second chair sit-stands (number), 6-minute walk distance (meters), and normalized psoas muscle area (cm2/m) were measured for 77 consenting patients from January 1, 2018, to April 1, 2019. Imbalanced random forest classification estimated probability of a composite postoperative outcome, which included mortality, respiratory complications, anastomotic leak, delirium, length of stay ≥14 days, discharge to nursing facility, and readmission. G-mean error was used to compare predictive accuracy among indexes. RESULTS: Median grip strength was 38 kg (25th-75th percentiles, 31-44), number of sit-stands 11 (10-14), psoas muscle area to height ratio 6.9 cm2/m (6.0-8.2), and 6-minute walk distance 407 m (368-451). There was generally weak correlation between these metrics, with the highest between 30-second sit-stands and 6-minute walk distance (r = 0.57). Age, degree of patient-reported exhaustion, and the 4 objective metrics comprised the Esophageal Vitality Index, which had a lower G-mean error of 32% (31-33) than the Fried Frailty Index, 37% (37-38), and the Modified Frailty Index, 48% (47-48). CONCLUSIONS: The Esophageal Vitality Index, an objective, simple assessment consisting of grip strength, 30-second chair sit-stands, 6-minute walk, and psoas muscle area to height ratio outperformed commonly used frailty indexes in predicting postesophagectomy mortality and morbidity. The index provides a robust picture of patients' fitness for surgery beyond the qualitative "eyeball" test.

Adverse Outcomes after Advanced EVAR in Patients with Sarcopaenia.

PURPOSE: To determine whether low total psoas muscle area (tPMA), as a surrogate for sarcopaenia, is a predictor of adverse outcomes in patients undergoing advanced EVAR. MATERIALS AND METHODS: A retrospective review of medical records was performed for 257 patients who underwent advanced EVAR (fenestrated or branched technique) in a single tertiary centre from 1 January 2008 to 1 September 2019. The study cohort was divided into tertiles based on tPMA measurement performed independently by two observers from a peri-procedural CT scan at the level of mid-L3 vertebral body. The low tertile was considered sarcopaenic. Logistic regression analysis was used to assess the association of tPMA with 30-day mortality and post-procedural complications. Univariable analysis and adjusted multivariable Cox regression were used to assess the association of tPMA with all-cause mortality. RESULTS: A total of 257 patients comprised 193 males and 64 females with the mean age of 75.4 years (± 6.8) were included. Adjusted multivariable Cox regression revealed an 8% reduction in all-cause mortality for every 1 cm2 increase in tPMA, P < 0.05. TPMA was associated with 30-day mortality (OR 0.85, 95% CI 0.75-0.96, P < 0.05) and spinal cord ischaemia (SCI) (OR 0.89, 95% CI 0.82-0.97, P < 0.05). For remaining post-procedural complications, tPMA was not a useful predictive tool. TPMA correlated negatively with hospital stay length (rs-0.26, P < 0.001). Patients with lower tPMA were more likely to be discharged to a rehabilitation center (OR 0.93, 95% CI 0.87-0.98 , P < 0.05). CONCLUSION: Measurement of tPMA can be a useful predictive tool for adverse outcomes after advanced EVAR. LEVEL OF EVIDENCE: Level 3, Retrospective cohort study.

Psoas muscle area and attenuation are highly predictive of complications and mortality after complex endovascular aortic repair.

OBJECTIVE: The present study evaluated the psoas muscle area and attenuation (radiodensity), quantified by computed tomography, together with clinical risk assessment, as predictors of outcomes after fenestrated and branched endovascular aortic repair (FBEVAR). METHODS: The present single-center study included 504 patients who had undergone elective FBEVAR for pararenal or thoracoabdominal aortic aneurysms. The clinical risk assessment included age, sex, comorbidities, body mass index, glomerular filtration rate, aneurysm size and extent, cardiac stress test results, ejection fraction, and American Society of Anesthesiologists (ASA) score. Preoperative computed tomography was used to measure the psoas muscle area and attenuation at the L3 level. The lean psoas muscle area (LPMA; area in cm2 multiplied by attenuation in Hounsfield units [HU]) was calculated by multiplying the area by the attenuation. The risk factors for 90-day mortality, major adverse events (MAEs), and long-term mortality were determined using multivariable analysis. MAEs included 30-day or in-hospital death, acute kidney injury, myocardial infarction, respiratory failure, paraplegia, stroke, and bowel ischemia. A novel risk stratification method was proposed according to the strongest predictors of mortality and MAEs on multivariable analysis. RESULTS: The 30-day mortality, 90-day mortality, and MAE rates were 2.0%, 5.6%, and 20%, respectively. The independent predictors of 90-day mortality were chronic obstructive pulmonary disease, chronic kidney disease, ASA score, and LPMA. The independent predictors of MAEs were aneurysm diameter, glomerular filtration rate, and LPMA. For long-term mortality, the independent predictors were chronic kidney disease, congestive heart failure, extent I-III thoracoabdominal aortic aneurysms, ASA score, and LPMA. The patients were stratified into three groups according to the ASA score and LPMA: low risk, ASA score II or LPMA >350 cm2HU (n = 290); medium risk, ASA score III and LPMA ≤350 cm2HU (n = 181); and high risk, ASA score IV and LPMA ≤350 cm2HU (n = 33). The 90-day mortality and MAE rates were 1.7% and 16% in the low-, 7.2% and 24% in the medium-, and 30% and 33% in the high-risk patients, respectively (P < .001 and P = .02, respectively). Patients with ASA score IV and LPMA <200 cm2HU, indicating sarcopenia (n = 14) had a 43% risk of death within 90 days. The 3-year survival estimates were 80% ± 3% for the low-, 70% ± 4% for the medium-, and 35% ± 9% for the high-risk patients (P < .001). The mean follow-up time was 3.1 ± 2.3 years. CONCLUSIONS: LPMA was a strong predictor of outcomes and the only independent predictor of both mortality and MAEs after FBEVAR. A high muscle mass was protective against complications, regardless of the ASA score. Risk stratification based on the ASA score and LPMA can be used to identify patients at excessively high operative risk.

CT evaluated sarcopenia signals: Shorter survival for small cell lung cancer patients.

Sarcopenia is an independent risk factor for morbidity and mortality in patients suffering from small cell lung cancer (SCLC), however, a universal indicator of sarcopenia usable in clinical practice is still missing. A novel indicator for describing the severity of cancer could be helpful in tailoring the anti-tumor therapy. The aim of this study was to evaluate the computed tomography (CT) scans of total muscle area and radiation attenuation in patients suffering from small cell lung cancer. We used staging CT scans performed at the time of diagnosis to measure total muscle area (TMA) and average psoas density (PD) at level of the 3rd lumbar vertebra. TMA and PD were statistically evaluated in association with overall survival and disease staging. We used Mann-Whitney test and Spearman´s correlation coefficient for statistical testing and p-value under 0.05 was considered statistically significant. Retrospectively we examined 47 patients suffering from SCLC (mean age 65.05+/-7.3 years, BMI 23.97+/-4.4 kg/m2, BSA 1.77+/-0.2 m2, 30-day mortality was 4.3 % with 10 months median survival). As sarcopenia was pointed TMA under 55 and 39 cm2/m2 for men and women respectively. The sarcopenic patients had significantly shorter median survival (7 vs. 11 months, p=0.05). We observed a significant relationship between survival and performance status (Spearman´s correlation, R=-0.39, p=0.05). The patients were divided into two groups according to the extensive (ED, n=34) or limited (LD, n=13) form of the disease. We observed significant difference in PD (42.49+/-6.1 vs. 47.67+/-4.5 HU, p=0.006) between ED vs. LD groups.

Impact of Total Psoas Area and Lean Muscular Area on Mortality after Endovascular Aortic Aneurysm Repair.

BACKGROUND: Sarcopenia has assumed growing relevance as a morbimortality predictor after major abdominal surgery. The aim of this study is to access total psoas muscle area (TPA) and lean muscle area (LMA) impact in morbimortality after elective endovascular abdominal aortic aneurysm repair (EVAR). METHODS: Asymptomatic patients submitted to aortic endoprosthesis implantation between January 1, 2014 and December 31, 2018 at our vascular surgery department were retrospectively evaluated. After exclusion criteria were applied, 105 patients were included in the study; preoperative computed tomography scans were evaluated using OSIRIX software (Bernex, Switzerland). Two observers independently calculated TPA at the most caudal level of the L3 vertebra and respective density, therefore calculating LMA. Patients were separated by tertiles with the lowest being considered sarcopenic and with higher muscle steatosis and compared with the higher tertiles. Patient demographics and intraoperative and postoperative period variables were collected. Charlson comorbidity index was calculated and surgical complications classified according to Clavien-Dindo. The intraclass correlation coefficient and Bland-Altman plot were made to characterize interobserver variability. Survival analysis was performed with the Kaplan-Meier method, and differences between survival curves were tested with the log-rank test. The effect of sarcopenia on patient survival was assessed using Cox proportional hazard models. RESULTS: Considering TPA, univariate analyses revealed that patients in the lower tertile had inferior survival (P = 0.03), whereas multivariate analyses showed increased likelihood of mortality (P = 0.039, hazard ratio (HR) 3.829). For LMA, univariate analyses revealed that patients in the lower tertile had inferior survival (P = 0.013), whereas multivariate analyses showed increased likelihood of mortality (P = 0.026, HR 4.153). When analyzing patients in the lowest tertile of both TPA and LMA, both univariate (P = 0.002) and multivariate (P = 0.018, HR 4.166) analyses reveled inferior survival. CONCLUSIONS: Our study reveals reduced survival in patients with low TPA and low LMA submitted to elective EVAR; these factors should probably be taken into consideration in the future for preoperative risk evaluation and surgical planning.

Prognostic impact of the psoas muscle index, a parameter of sarcopenia, in patients with diffuse large B-cell lymphoma treated with rituximab-based chemoimmunotherapy.

Muscle mass, defined as the psoas muscle index (PMI), is an important parameter of sarcopenia and it has been shown to be a prognostic factor of non-hematological cancers. This study aimed to investigate the prognostic impact of sarcopenia defined using PMI measurement in patients with diffuse large B-cell lymphoma treated with R-CHOP. We retrospectively investigated the impact of pretreatment PMI on survival and response to treatment. One hundred and twenty patients with DLBCL were included in the study, of whom 65 had baseline sarcopenia according to the defined PMI cutoffs. Sarcopenic patients displayed a worse response to treatment compared with non-sarcopenic patients. In a multivariate analysis, sarcopenia remained predictive of outcomes for overall survival (p = .009), progression free survival (p = .028), and response to treatment (p = .006). Sarcopenia defined by evaluating PMI is a simple and routinely applicable method that can predict poor outcomes in patients with DLBCL.

Sarcopenia is Associated with Nonunion of Open Tibia and Ankle Fractures.

Background: Sarcopenia is a clinical syndrome of diminished muscle mass and function associated with disability, poor surgical outcomes, and mortality. Open fractures of the tibia and ankle have a high risk for complications including nonunion and surgical site infection (SSI). The purpose of this study is to determine if sarcopenia is associated with SSI and nonunion in individuals that sustain open fractures of the tibia and ankle. Methods: 111 consecutive adults who underwent operative fixation of open fractures of the tibia or ankle from 2006-2017 with preoperative CT of the abdomen and pelvis were retrospectively identified at a single institution. Eleven patients were lost to follow-up. The psoas index (PI = (RPA+LPA)/ height2 (cm2/m2)) was calculated from bilateral psoas cross sectional areas measured on axial CT scans at the L3 pedicle. Patients were stratified by the presence of sarcopenia as defined by established gender specific PI cut-offs of <3.85 cm2/m2 (women) and <5.45 cm2/m2 (men). Records were also abstracted for comorbidities to determine a Charlson Comorbidity Index (CCI) score and postoperative complications including fracture nonunion and SSI. Logistic regression was used to model the relationships between complications, sarcopenia and other factors. Results: 16/100 (16%) patients met gender specific criteria for the diagnosis of sarcopenia by PI. There was no difference in gender, age, or burden of medical comorbidity according to CCI between the sarcopenic and non-sarcopenic groups (all p>0.05). Nonunion occurred in 6 patients with sarcopenia (38%) and 12 without sarcopenia (18%) (Relative risk=2.42, 95%C!=1.08-5.43, p=0.0314). No association was found between sarcopenia and SSI, BMI, smoking status, ISS, and Gustilo and Anderson (GA) classification of open fracture (all p>0.2). GA classification was strongly associated with infection, with each successive classification having a nearly 3-fold increase in risk (p=0.0217). Conclusion: Sarcopenia is an independent risk factor for fracture nonunion following operative fixation of open tibia or ankle fracture, but is not predictive of surgical site infection. Gustilo Anderson classification is strongly associated with SSI risk. Psoas index is a straightforward and objective method of identifying sarcopenia in patients with open fractures. Diagnosing sarcopenia in these individuals can inform medical decision making and patient counseling regarding risk for nonunion. Further work is needed to identify effective interventions to improve outcomes in these patients.Level of Evidence: III.

Associations between the psoas major muscle index and the presence and severity of coronary artery disease.

The associations between the presence and severity of coronary artery disease (CAD) and measurements of the psoas major muscle (PMM) as assessed by multidetector row coronary computed tomography angiography (MDCT) are not known.We enrolled 793 patients who were clinically suspected to have CAD or had at least one cardiac risk factor and had undergone MDCT. The number of significantly stenosed coronary vessels (VD) and measurements of the PMM index (PMMI) were determined using MDCT.PMMI in the CAD group was significantly lower than that in the non-CAD group in males, but not females. In addition, the levels of PMMI tended to increase as the number of VD decreased in males. When male patients were divided into 2 groups according to median value of age, that is, relatively younger (53.4 ±â€Š9.2 years) and older (72.6 ±â€Š5.7 years) groups, the presence of CAD was independently associated with PMMI in the younger group by a multiple logistic regression analysis. The cut-off level of PMMI that gave the greatest sensitivity and specificity for the diagnosis of CAD in younger males was 8.3 cm/m (sensitivity 0.441, specificity 0.752).In conclusion, PMMI may be an imaging marker for evaluating the presence and/or severity of CAD in males, and particularly in the non-elderly.

Iliopsoas the Hidden Muscle: Anatomy, Diagnosis, and Treatment.

The iliopsoas is a deep muscle group which anatomically connects the spine to the lower limbs. It is composed of the iliacus, psoas major, and psoas minor muscles. The iliopsoas functions as the primary hip flexor. Because the iliopsoas is important for daily activities, including sports, impairments and pathology associated with this muscle group can cause significant limitations. Evaluating pathology associated with the iliopsoas muscle group can be challenging because the patient's complaints are often vague and difficult to discern from other hip problems. This article will review relevant anatomy, discuss common pathologies, present clinical based examination methods, and outline conservative treatment interventions focusing on manual therapy and active exercises.

Pre-sarcopenia is the prognostic factor of overall survival in early-stage hepatoma patients undergoing radiofrequency ablation.

Sarcopenia might have impact on the outcome of patients with hepatoma carcinoma (HCC). This study was to determine whether pre-sarcopenia is associated with the outcome of HCC patients undergoing radiofrequency ablation (RFA).Patients with newly diagnosed HCC undergoing RFA were enrolled. We excluded patients without pre-RFA abdominal computed tomography or with incomplete ablation. Psoas muscle area index was calculated at the mid-lumbar 3 level of computed tomography images with the manual trace method. Pre-sarcopenia was defined as psoas muscle area index less than 4.24 and 2.50 cm/m for males and females respectively. The demographics and clinical characteristics were recorded before RFA.All patients were followed regularly until death or end of 2018. A total of 136 patients, including - BCLC stage 0 (n = 44, 32.4%) and - stage A (n = 92, 67.6%), were enrolled (males/females: 78/58, age: 65.4 years) with a mean follow-up period of 3.84 years. There were 75 patients (55.1%) with HCC recurrence and 47 patients (34.6%) with mortality during follow-up. Twenty-two (16.2%) patients were diagnosed with pre-sarcopenia. Multivariate analysis showed pre-sarcopenia (HR: 2.110 (1.092-4.078); P = .026) was the only factor significantly associated with overall survival (OS); however, there were no factors associated with HCC recurrence.For patients without and with pre-sarcopenia, the 1-, 3-, and 5-year OS rates were 92.0%, 77.6%, 68.9%, and 81.8%, 54.5%, 44.1% respectively (P = .007). For early-stage HCC patients undergoing RFA, pre-sarcopenia is the prognostic factor of OS, but not of recurrence, with a worse 5-year OS rate of 44.1%.

Individuals with mild-to-moderate hip osteoarthritis walk with lower hip joint contact forces despite higher levels of muscle co-contraction compared to healthy individuals.

OBJECTIVE: To compare hip joint contact forces (HJCF), hip muscle forces, and hip muscle co-contraction levels between individuals with mild-to-moderate hip osteoarthritis (OA) and healthy controls during walking. DESIGN: Eighteen participants with mild-to-moderate hip OA and 23 healthy controls walked at a self-selected speed while motion capture and electromyographic data were synchronously collected. HJCF were computed using a calibrated electromyography-informed neuromusculoskeletal model. Hip joint contact forces, muscle forces, and co-contraction indices for flexor/extensor and adductor/abductor muscle groups were compared between groups using independent sample t-tests (P < 0.05). RESULTS: There was no between-group difference in self-selected walking speed. On average, participants with hip OA walked with 11% lower first peak (mean difference 235 [95% confidence interval (CI) 57-413] N) and 22% lower second peak (mean difference 574 [95%CI 304-844] N) HJCF compared to controls. Hip muscle forces were also significantly lower in the hip OA compared to control group at first (mean difference 224 [95%CI 66-382] N) and second (mean difference 782 [95%CI 399-1164] N) peak HJCF. Participants with hip OA exhibited higher levels of hip muscle co-contraction in both flexor/extensor and adductor/abductor muscle groups. Consistent with existing literature, hip joint angles (extension, adduction) and external moments (flexion, extension, adduction) were lower in hip OA compared to controls. CONCLUSION: Lower HJCF were detected in mild-to-moderate hip OA, primarily due to lower hip muscle force production, and despite higher levels of hip muscle co-contraction. Findings suggest that lower loading of the hip joint during walking is a feature of mild-to-moderate hip OA, which could have implications for the pathogenesis of hip OA and/or disease progression.

Role of Frailty and Comorbidity Status in Predicting Morbidity and Mortality in Patients with Acute Mesenteric Ischemia.

BACKGROUND: This study was performed to determine the association of frailty and comorbidity status with postoperative morbidity and mortality in patients with acute mesenteric ischemia (AMI). METHODS: Patients diagnosed with AMI between April 2006 and September 2019 were enrolled in this study. Frailty was evaluated by sarcopenia which was diagnosed by third lumbar vertebra psoas muscle area (PMA). Comorbidity status was evaluated by the Charlson Comorbidity Index (CCI) score. Univariate and multivariate analyses evaluating the risk factors for postoperative morbidity and mortality were performed. RESULTS: Of the 174 patients, 86 were managed conservatively and 88 underwent surgery. In surgically managed patients, 39.8% developed complications within 30 days of surgery. Ten patients died within 30 days of the operation. In the univariate analyses, white blood cell >10 g/L, low PMA, CCI score ≥2, and bowel resection were associated with postoperative complications. Multivariate analysis revealed that low PMA, CCI score ≥2, and bowel resection were independent predictors of postoperative complications. CONCLUSIONS: This study demonstrated that low PMA, CCI score ≥2, and bowel resection were independent risk factors for postoperative complications in patients with AMI. Preoperative assessment of frailty using PMA and the evaluation of comorbidity status using CCI may serve as helpful tools in preoperative risk assessment and should be integrated into scoring systems for surgically treated AMI.

Trunk Muscle Cross-Sectional Area as a Predictive Factor for Length of Postoperative Hospitalization after Surgical Aortic Valve Replacement.

PURPOSE: We investigated the utility of trunk muscle cross-sectional area to predict length of hospitalization after surgical aortic valve replacement (AVR) for aortic stenosis (AS). METHODS: Adult AS patients who underwent isolated AVR at a single institution were studied. The cross-sectional area of the erector spinae muscles (ESM) at the first and second lumbar vertebrae and that of the psoas muscle (PM) at the third and fourth lumbar vertebrae were measured on preoperative computed tomography (CT). Each was indexed to body surface area. Risk factors for prolonged postoperative hospitalization (>3 weeks) were assessed using multivariate regression analyses. RESULTS: Of 56 patients (mean age 76 ± 9 years; 25 men), 20 (35.7%) patients required prolonged hospitalization. A smaller indexed ESM cross-sectional area at the first lumbar vertebra (per 1 cm/m2, odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.57-0.88, P <0.01) and lower preoperative serum albumin level (per 0.1 g/dL, OR = 0.83, 95% CI = 0.70-0.99, P <0.05) were shown as independent predictors. Indexed PM cross-sectional area was not statistically significant. CONCLUSION: The cross-sectional area of the trunk muscles can be used to identify patients at risk for prolonged hospitalization after AVR for adult AS.

Paediatric reference values for total psoas muscle area.

BACKGROUND: Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross-sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3-4 and L4-5. METHODS: In this cross-sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1-16 years who required abdominal cross-sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3-4 and L4-5 were measured in square millimetres (mm2 ) as the sum of left and right PMA. Age-specific and sex-specific tPMA percentile curves were modelled using quantile regression. RESULTS: Computed tomography images from 779 children were included. Values of tPMA at L4-5 were significantly larger than at L3-4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm2 at L3-4 and from 447 to 2704 mm2 for L4-5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm2 at L3-4 and from 498 to 3513 mm2 at L4-5. Intraclass correlation coefficients were excellent at L3-4 (0.97, 95% CI 0.94 to 0.981) and L4-5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3-4 r = 0.90; L4-5 r = 0.90) and for girls (L3-4 r = 0.87; L4-5 r = 0.87). An online application was subsequently developed to easily calculate age-specific and sex-specific z-scores and percentiles. CONCLUSIONS: We provide novel paediatric age-specific and sex-specific growth curves for tPMA at intervertebral L3-4 and L4-5 levels for children between the ages of 1-16 years. Together with an online tool (https://ahrc-apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.