Hip fractures are common in older adults and are often associated with muscle loss and frailty. While many studies focus on overall muscle reduction (sarcopenia), the role of regional muscle balance around the hip remains unclear. This prospective observational study aims to evaluate whether differences in muscle distribution, particularly between the gluteus medius and psoas muscles measured using computed tomography (CT), are associated with different hip fracture patterns. The study also investigates the potential effects of socioeconomic status, nutritional risk, and comorbidity burden on fracture configuration. Understanding how regional muscle characteristics relate to hip fracture types may provide new insight into biomechanical mechanisms and support future prevention and rehabilitation strategies for older adults.

Hip fractures represent a major cause of morbidity and mortality in the aging population and are frequently associated with sarcopenia and frailty. Although previous studies have primarily focused on global muscle mass reduction, the biomechanical relevance of regional muscle distribution surrounding the hip joint has not been sufficiently investigated. This prospective observational study evaluates the association between regional muscle balance and hip fracture patterns in older adults using CT-based muscle measurements.

Participants aged 60 years and older presenting with hip fractures following low-energy falls were included. Demographic characteristics, socioeconomic status, nutritional risk assessed by the Geriatric Nutritional Risk Index (GNRI), and comorbidity burden measured by the Charlson Comorbidity Index were recorded. Cross-sectional muscle areas, including total skeletal muscle, bilateral psoas muscle, and gluteus medius muscle, were measured on standardized CT images. The gluteus-to-psoas ratio was calculated to assess regional muscle distribution.

The primary objective of the study is to determine whether CT-based regional muscle characteristics are associated with hip fracture configuration, specifically intertrochanteric and femoral neck fractures. Secondary objectives include evaluating the potential influence of nutritional and socioeconomic factors on fracture patterns. Findings from this study may improve understanding of hip fracture biomechanics and contribute to future risk stratification and individualized rehabilitation approaches.

Inclusion Criteria:

• Age ≥60 years
• Presentation with hip fracture following a low-energy fall
• Availability of pelvic computed tomography (CT) imaging at admission
• Ability to provide written informed consen

Exclusion Criteria:

• Pathological fractures
• Active malignancy
• Subtrochanteric fractures (≥5 cm distal to the lesser trochanter)
• High-energy trauma
• Neuromuscular disorders affecting muscle morphology
• Inflammatory systemic diseases
• Hemiparesis secondary to cerebrovascular events
• Refusal to participate in the study

Older adults aged 60 years and older presenting with hip fractures after low-energy falls were prospectively enrolled. Participants were evaluated in a tertiary care orthopedic trauma center, and fracture types were classified as femoral neck fracture or intertrochanteric femur fracture. All participants underwent standardized clinical assessment and CT-based muscle measurements at admission.