Application of virtual crack closure technique to simulate a burst fracture for an osteolytic vertebra, a case study.

A main concern of clinicians for patients with an osteolytic vertebra is assessment of a fracture, however a higher concern exists for occurrence of a burst fracture because of its more complexity and less chance of healing. This paper aimed to assess a burst fracture risk using a well-known technique in fracture mechanics as virtual crack closure technique for a case study, involved with multiple myeloma in a lumbar vertebra. The reliability of the model to simulate the ultimate strength for a vertebral segment was exhibited by simulation of anin-vitrocompression test. Then the progression of osteolytic damage for the case study was simulated according to a virtual thermal flux pattern, applied successfully in a recent publication, and propagation of a potential crack which was attributed to lead a burst fracture in the following, was examined under an extension condition for the vertebra versus progression of the osteolytic damage. The significant finding of this study was a graph that exhibited propagation of the crack up to an unstable condition versus the progression of osteolytic damage. The model showed that before increase of the osteolytic damage in the vertebra equal to 20%, there was a minor growth of the potential crack, however in the following, the crack propagated versus progression of damage that led to instability of the vertebra for an osteolytic damage equal to 50%. This study showed eligibility of the presented modeling technique for estimation of the maximum progression of an osteolytic lesion for a case study that may expose a serious burst fracture. In spite of promising results of the simulation method, proposed here to examine a burst fracture for a diseased vertebra, its efficiency for clinical applications requires more complementary studies in the future.