Substantial Loss of Skeletal Muscle Mass Occurs After Femoral Fragility Fracture

Reliability and Diagnostic Accuracy of EOS Full-Body Upright Imaging for Sarcopenia: A Retrospective Study Comparing Thigh Muscle to CT-Derived Psoas Muscle Measurements

BACKGROUND

Sarcopenia increases postoperative complication and mortality rates in elderly patients. Although measurement of the psoas muscle area on computed tomography (CT) scans is traditionally used to diagnose sarcopenia, CT is not routine in orthopaedic practice and causes unnecessary radiation exposure. EOS, a low-dose full-body imaging modality, captures musculoskeletal structures in an upright position, offering an alternative for sarcopenia diagnosis.

METHODS

Patients ≥18 years of age were included in this retrospective study if they had undergone non-contrast CT spine and EOS imaging between May 2022 and May 2024. Psoas muscle measurements at L3 and L4 were made using non-contrast CT scans, while thigh muscle measurements were obtained with EOS imaging. Inter- and intra-rater reliabilities were assessed using intraclass correlation coefficients (ICCs). Predicted probabilities for L4-psoas sarcopenia were determined through logistic regression, controlling for demographic covariates and validated with an 80% to 20% train-validate split. Sarcopenia cutoffs for anteroposterior (AP) thigh thickness and lateral (LAT) quadriceps thickness were determined with use of the Youden index.

RESULTS

Sarcopenia was identified in 23.1% of 134 patients (85 female and 49 male; 121 White, 7 Black, and 6 Hispanic) on the basis of L4-psoas muscle index thresholds. EOS and CT measurements showed excellent ICCs (≥0.90). Multivariable regressions identified AP thigh thickness and LAT quadriceps thickness as significant predictors of psoas area and L4-psoas sarcopenia. The area under the receiver operating characteristic curve for identifying L4-psoas sarcopenia was 0.85 for AP thigh thickness and 0.77 for LAT quadriceps thickness. Cutoffs were 12.47 cm (males) and 10.68 cm (females) for AP thigh thickness, and 3.23 cm (males) and 2.20 cm (females) for LAT quadriceps thickness. In the validation cohort of 27 patients, the AP thigh thickness model showed 0.94 sensitivity and 0.89 specificity, while the LAT quadriceps thickness model showed 0.70 sensitivity and 1.00 specificity. Applying these cutoffs to the entire data set showed that 66.7% of males and 75.0% of females with measurements below both cutoffs had sarcopenia.

CONCLUSIONS

EOS is a reliable alternative to CT for muscle mass assessment and sarcopenia diagnosis. EOS may be a valuable tool for assessing sarcopenia without a CT scan, as thigh muscle measurements via EOS correlate well with CT-derived psoas measurements. This imaging modality aids in early sarcopenia diagnosis, potentially enhancing preoperative planning and reducing radiation exposure, unnecessary costs, and resource utilization.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Food Insecurity Is Common in the Orthopaedic Trauma Population

INTRODUCTION

Food insecurity is the condition of limited access to healthy and safe food. Malnutrition resulting from food insecurity is a concern particularly in the surgical population due to the association with impaired healing. This aim of this study was to report the incidence and risk factors for food insecurity in the orthopaedic trauma population.

METHODS

Orthopaedic trauma centers at three distinct regions of the United States enrolled patients who had undergone extremity or pelvis fracture fixation within the previous 6 months. Participants completed the United States Department of Agriculture Household Food Insecurity Survey, and food insecurity was defined as a score ≥3. In addition, participants recorded patient demographics and injury/treatment/household characteristics and completed information about diet quality. Diet quality was compared between households with and without food insecurity using chi-square or Fisher exact tests. Logistic regression was used to create a multivariable model of factors associated with greater odds of food insecurity.

RESULTS

Food insecurity was documented in 11.5% (81/703) of households. Households with food insecurity were less likely to report daily consumption of fruit, vegetables, and protein-rich foods. We found a greater odds of food insecurity among households with a yearly income of <$50,000 (odds ratio = 4.30 [95% confidence interval = 2.07 to 8.92], P < 0.001), tobacco use (2.33 [1.26 to 4.28], P = 0.007), Medicaid or no insurance (2.34 [1.19 to 4.62], P = 0.014), and Hispanic or Latino ethnicity (4.55 [1.69 to 12.24], P = 0.003), for each 10-year decrease in age (1.19 [1.00 to 1.40], P = 0.045), multiple surgically treated fractures (2.41 [1.08 to 5.35], P = 0.031), and for each additional 15 minutes of travel time to the nearest grocery store (2.12 [1.37 to 3.26], P < 0.001).

CONCLUSION

Food insecurity is common in the orthopaedic trauma population, and households with food insecurity are more likely to have low diet quality. Nutrition supplementation during the healing phase after trauma and referral to nutrition assistance programs has the potential to mitigate malnutrition and prevent negative outcomes resulting from food insecurity.

Feasibility, acceptability and prognostic value of muscle mass and strength measurement in patients with hip fracture: a systematic review

PURPOSE

Sarcopenia is diagnosed on the basis of low muscle strength, with low muscle mass used to confirm diagnosis. The added value of measuring muscle mass is unclear. We undertook a systematic review to assess whether muscle mass measurement in patients with hip fracture was acceptable, feasible and independently associated with adverse outcomes.

METHODS

Electronic databases (MEDLINE, EMBASE, CENTRAL, CINAHL, Clinicaltrials.gov) were searched for studies of patients with hip fracture aged ≥ 60 with perioperative muscle mass or strength assessments. Associations with postoperative outcomes including death, length of stay and activities of daily living were extracted. Risk-of-bias was assessed using the AXIS and ROBINS-I tools. Due to the degree of study heterogeneity, data were analysed by narrative synthesis.

RESULTS

The search strategy identified 3317 records. 36 studies were included with 7860 participants. Acceptability of muscle mass measurement was not assessed, but measurement appeared feasible using biompedance, dual energy x-ray absorptiometry and computed tomography. Univariate analyses indicated that lower muscle mass was associated with higher death rates at 30 days, worse mobility, worse activity of daily living metrics and worse physical performance but there was no significant association with length of stay or postoperative complications. Four studies included both muscle mass and strength in multivariable analyses; muscle mass was a significant independent predictor of only one adverse outcome in a single study after adjustment for muscle strength and other predictor variables.

CONCLUSION

Current data suggest that muscle mass assessment offers no additional prognostic information to muscle strength measures in patients with hip fracture.

Radiographic Thigh Muscle Measurements Are a Reliable Predictor of Psoas Area and Sarcopenia

BACKGROUND

Sarcopenia is associated with falls, fractures, postoperative complications such as periprosthetic joint infections and dislocations, and early mortality. Although cross-sectional imaging is currently used to diagnose sarcopenia, inexpensive and widely available screening tests are needed. The goal of this study was to investigate whether measurements of thigh muscles made on radiographs can predict psoas muscle area and the presence of sarcopenia as determined on computed tomography (CT) scans.

METHODS

A retrospective radiographic review was performed to measure thigh muscle area in the coronal and sagittal planes using the differential in soft-tissue attenuation. Psoas muscle area on CT at L3 and L4 served as the gold standard for the diagnosis of sarcopenia. The correlation between thigh muscle and psoas muscle areas was determined, and multivariable models were developed to identify predictors of psoas muscle area and sarcopenia.

RESULTS

Four hundred and fourteen patients (252 male, 162 female) were identified. Seventy-six (18.4%) of the patients had an L4 psoas muscle area below the sex-specific cutoff value for sarcopenia. Patients with sarcopenia on abdominal CT had significantly smaller thigh muscle measurements on all radiographic views. The mean and standard deviation of the thigh muscle measurements were determined for the entire cohort and for patients with sarcopenia, as well as for adults aged 18 to 40 years without sarcopenia to provide normative reference values. The intraclass correlation coefficients were >0.8 for all radiographic measurements. The anteroposterior-view measurement of thigh muscle width and lateral-view measurement of quadriceps height were identified as independent predictors of both psoas muscle area and sarcopenia.

CONCLUSIONS

Measurements of thigh muscle size made on radiographs can predict both psoas muscle area and sarcopenia. These measurements are a reliable and readily available screening tool to aid in the diagnosis and treatment of sarcopenia in the orthopaedic population.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Loss of Muscle Mass and Strength After Hip Fracture: an Intervention Target for Nutrition Supplementation

PURPOSEOF REVIEW

To summarize what is known about the deleterious effect of hip fracture on muscle mass and strength as well as the scientific evidence for post-surgical nutrition supplementation to maintain muscle and improve function.

RECENT FINDINGS

This review provides a discussion of the relationship between muscle mass, strength, and physical function following hip fracture, briefly describes the approaches to measuring lean mass, discusses prevalence of sarcopenia and malnutrition among older men and women with hip fracture, and reviews the effects of essential amino acids on muscle. Loss of muscle mass and strength following hip fracture is substantial with consequences for recovery of functional independence. EAA-based nutrition supplementation, which directly effects muscle, has potential to improve outcomes.