Muscle force sensitivity of a finite element fracture risk assessment model in osteogenesis imperfecta - biomed 2009
Fritz, J.M.; Guan, Y.; Wang, M.; Smith, P.A.; Harris, G.F.
Biomedical Sciences Instrumentation 45: 316-321
2009
ISSN/ISBN: 0067-8856 PMID: 19369782 Document Number: 630982
Osteogenesis imperfecta (OI) is a heritable bone fragility disorder characterized by skeletal deformities and increased bone fragility. There is currently no established clinical method for quantifying fracture risk in OI patients. A method for developing a finite element model of the femur to assist in fracture risk assessment of a selected patient with OI type I was created. The material properties were based on nanoindentation testing of OI bone specimens collected during routine surgery. Dynamic data from clinical gait analysis was used to prescribe joint reaction forces and moments in a quasi-static model. Muscle forces were prescribed according to current literature. Von Mises stresses were analyzed across all seven phases of the gait cycle and analyzed for sensitivity to changes in muscle forces. The model showed that the patient with OI was not at current risk for fracture during normal gait. The highest stress levels occurred during mid stance and loading response. Maximum von Mises stresses were most sensitive to the gluteal muscles. Insight provided by the model may be useful for similar clinical applications, more refined model development and an improved ability for fracture prediction.