From Structural WBCT Findings to Biomechanical Interpretation in Hallux Valgus: Current Evidence, Limitations, and Clinical Implications

Hallux valgus is increasingly characterized using weight-bearing computed tomography (WBCT), which provides three-dimensional information on first-ray alignment and articular relationships under load. However, structural abnormalities identified on static WBCT should not be equated with direct measurements of biomechanics or function. This narrative review examines the evidentiary transition from structural WBCT findings to biomechanical interpretation in hallux valgus. Normal first-ray mechanics provide the reference framework for evaluating altered tarsometatarsal alignment, first-metatarsal rotation, metatarsosesamoid relationships, and medial-column coupling. Throughout the review, three levels of evidence are distinguished: structural relationships directly demonstrated by WBCT, biomechanical interpretations supported by anatomical or experimental evidence, and dynamic functional or prognostic consequences that require independent validation. Within this framework, coexisting three-dimensional abnormalities may be interpreted as mechanically interrelated without implying a universal causal sequence. Postoperative WBCT can characterize residual or corrected structural relationships, but normalization of imaging parameters does not by itself establish restoration of dynamic function or superior clinical outcome. Computational modeling may extend patient-specific geometry toward mechanical estimation, although its validity depends on model assumptions and independent validation. The principal contribution of WBCT is therefore to provide detailed structural information under load that can inform biomechanical hypotheses, while the functional and prognostic significance of these findings remains to be established through dynamic and longitudinal studies.