Patient Specific Modeling of Musculoskeletal Fractures

Choosing and executing an optimal treatment plan for skeletal fractures in clinical practice is a complex procedure. Treatment decisions are often qualitative, based on general guidelines and experience/training of the orthopedic surgeons. Despite its potential to assist in quantifying fracture fixation and thus improve patient outcome, computational patient-specific modeling for selection and planning of fracture treatments is limited at present. During the past 25 years extensive work has been reported regarding patient specific finite element (FE) based modeling. Numerous studies have reported on the development, validation and automation of patient specific FE modeling techniques from quantitative CT data sets. However, a patient specific quantitative process that can be applied in a true clinical environment must cope with profound uncertainties such as; material property assignments, surface geometry and most of all uncertainty of in vivo load amplitudes and gait patterns which are usually only roughly estimated. In this chapter we review common techniques of patient specific modeling of bony structures, and present known limitations and sources of error. Method and experimental validation of a new CT based workflow for patient specific modeling of fracture fixation implementing principal strain ratios is presented.