Novel Technology Helps Predict Bone Strength and Impending Fractures in Benign Bone Lesions of the Femur

Pathologic femur fractures due to benign bone lesions are a rare but tragic event. Deciding which patients with benign bone lesions in the femur may fracture due to mechnical weakness and may benefit from surgery is based on clinical experience. This suffers from poor sensitivity and specificity. A novel technology, patient-specific CT-based high-order finite element (FE) models of femur, provides an accurate estimate of the risk of pathological fracture. These analyses account for the exact geometry and inhomogeneous material properties, are created in a semi-automated manner and have been validated by biomechanical studies on cadaveric femurs.

The purpose of this study was to prospectively analyze CT scans of patients with benign lesions in the femur and use the analysis results as a decision aid for the surgeon.

Five patients were included. Three with Non-Ossifying Fibroma and two with Fibrous Dysplasia. Three had proximal femur lesions and two had distal femur lesions. In two patients analysis indicated a high risk of fracture and these underwent surgery. In three patients the analysis indicated a low risk of fracture and they were consulted not to have surgery. None of these patients went on to fracture.

This prospective FEA outcome is the first clinical application of this decision aiding tool and sets the basis for further studies which will utilize this novel technology in the decision protocol for prophylactic fixation surgery in patients with benign femoral lesions.