Is decreased psoas volume a risk factor for hip fracture? A comparative study of patients with and without hip fractures using the exact matching technique

Introduction: Sarcopenia is linked to increased fall and hip fracture risk. However, studies often overlook comprehensively controlling for age, sex, bone mineral density (BMD), and body mass index (BMI). Our study aimed to determine if sarcopenia, determined by evaluating the psoas muscle volume, is an independent risk factor for hip fractures. We employed a methodological approach that includes the exact matching technique. Methods: In this cross-sectional comparative study, we compared the data of patients who sustained hip fractures between 2015 and 2021 with those of a control group from a health screening center in a single center. The study included 545 patients with hip fractures and 1292 without fractures. We collected data on demographics, BMD determined using dual-energy X-ray absorptiometry, and abdominal and pelvic computed tomography (APCT) scans for psoas muscle volume analysis. Results: The analysis after exact matching of 266 pairs revealed that psoas volume/height2 was the most significant and dominant risk factor among the evaluated indices. Multivariate logistic regression analysis, adjusting for age, sex, BMI, and BMD, identified height or height2-adjusted psoas muscle volume as an independent risk factor for hip fractures (p = 0.042 and p = 0.002, respectively). Age, female sex, lower BMI, and lower BMD were associated with an increased risk of hip fractures. Conclusion: Decreased psoas muscle volume adjusted for patient height independently predicts hip fracture risk. Psoas volume assessment via APCT is a practical tool for identifying at-risk individuals, emphasizing the necessity of including sarcopenia in hip fracture risk assessments.