Computed tomography-derived bone and muscle biomarkers after fragility hip fracture: readiness for precision risk stratification

Fragility hip fracture is heterogeneous in local skeletal competence, physiological reserve, and recovery potential. Computed tomography (CT), when already acquired for clinical care, can provide proximal-femoral attenuation or quantitative CT-derived bone mineral density, muscle cross-sectional area, and composition metrics. This Mini Review separates acute fracture-status discrimination, pre-fracture longitudinal prediction, and post-index-fracture prognostication. Local femoral attenuation has been associated with fixation-related complications, but it is an indirect structural marker whose interpretation depends on geometry, loading, reduction, and implant–bone interactions. Muscle composition can complement size, but neither directly measures force, coordination, or functional performance. High apparent discrimination frequently derives from the development sample; evidence of added value over clinical predictors, calibration, and independent validation remains limited. We organize interpretation by anatomy, metric, outcome, and time, and illustrate how structural imaging could be combined with clinical, functional, and biomechanical measurements for four post-fracture endpoints. This is an endpoint-specific evidence interpretation framework, not a validated prediction model or treatment algorithm. Prognostic enrichment must be distinguished from treatment-effect modification. Harmonized measurements, external validation, and prospective evaluation of biomarker-guided decisions are required before these phenotypes can support individualized interventions.