Weight‐bearing computed tomography volumetric analysis for diagnosis of syndesmotic instability: A new standard of care?

Assessing the severity and clinical impact of syndesmotic injury, especially when subtle, remains among the most diagnostically challenging conditions in foot and ankle orthopaedics. The distal tibiofibular syndesmosis is a complex, three-dimensional (3D) joint critical to ankle stability, and substantial injury to its ligament complex-especially if undetected or undermanaged-can result in long-term functional impairment. Unfortunately, routine clinical and conventional imaging evaluations are often inconclusive, falling short of capturing the dynamic and subtle nature of syndesmotic instability. Moreover, while myriad techniques have been reported to assist with diagnosis, none have proven reliably effective in isolation nor superior to comparison with the patient's uninjured side. Currently, there exists no singular test that can reproducibly function as a binary endpoint for diagnosis, suggesting that the future of accurate diagnosis-particularly of subtle instability, which can occur in various planes-will require either a composite testing endpoint, more sensitive 3D imaging modalities supported by artificial intelligence databases, or both. As orthopaedic practice advances towards individualised, precision-based care, diagnostic modalities must evolve to better reflect functional anatomy and quantify pathology in multiple planes at once. Weight-bearing computed tomography (WBCT) has emerged as a transformative tool that enables high-resolution, comparative 3D assessment of the syndesmosis under physiological load. Cadaveric and clinical studies have demonstrated WBCT's high diagnostic accuracy, reproducibility and efficiency-especially when integrated with automated 3D volumetric analysis. Quantitative thresholds such as side-to-side 3D volume differences or lateral translation measurements provide robust criteria for instability. Since it has been demonstrated that these imaging techniques are more accurate when comparing the injured to the uninjured limb rather than using population norms, the contralateral side can serve as an internal reference-improving precision and reducing reliance on generalised values. New machine learning algorithms using WBCT now allow real-time, high-accuracy evaluation with almost immediate comparative results. As normative databases grow, these algorithms will improve, clarifying variations between a patient's two ankles. Standardised software can also reduce measurement errors still common with conventional assessments. Despite its advantages, WBCT adoption is limited by cost and integration challenges. Nonetheless, its expanding applications represent a shift in orthopaedic diagnostics towards more functional, individualised imaging.