Personalized Biomechanical Modeling of Pathologic Fracture: CTFEA Reveals Limitations of Traditional Fracture Risk Assessment in Benign Bone Tumors.

Benign bone tumors such as chondroblastoma, giant cell tumors, and aneurysmal bone cysts are rare but clinically significant lesions that frequently occur in the epiphyseal regions of long bones, particularly near load-bearing joints in children and young adults. These tumors compromise the structural integrity of bone, leading to an elevated risk of pathological fracture. Traditional methods for estimating fracture risk rely on simple geometric thresholds and volumetric ratios, but they fail to account for patient-specific differences in bone geometry, material heterogeneity, and physiological loading conditions. As a result, risk is often misclassified, which may lead to either overtreatment or missed prevention opportunities. To address this limitation, this study presents a novel alternative method (NAM); computational framework using patient-specific computed tomography (CT)-based finite element analysis (CTFEA) to evaluate fracture risk in four patients with benign knee tumors. Clinical CT imaging and motion capture-informed joint loading were used to develop anatomically accurate, mechanically calibrated models incorporating nonlinear bone behavior. CTFEA simulations focused on walking, jogging, and partial weight-bearing conditions captured localized stress and strain distributions and were benchmarked against clinical and volumetric assessment criteria. CTFEA outperformed traditional methods by revealing mechanical vulnerabilities, including in cases classified as low-risk clinically-through its ability to simulate individualized loading scenarios. These findings highlight the transformative potential of CTFEA as a non-invasive, patient-specific alternative to animal or oversimplified models, with direct implications for pre-operative planning and fracture risk stratification in orthopedic surgery.