A RIGID BODY AND SPRING MODEL OF THE LUMBAR SPINE WHICH CONSIDERS THE MECHANICAL LOADS AT THE BONE-SCREW INTERFACE

摘要

A spinal instrument with pedicle screws is one of the most effective surgical techniques for correction of spinal deformity. However, when excessive mechanical loads are applied on the implant upon the fixation, there is a concern for back out of the screw in the cases with poor bone condition such as osteoporosis. For that reason, the mechanical loads at the bone-screw interface should be analyzed for safe and successful correction.A rigid body and spring model (RBSM) is a potentially useful computational model that can be used to predict the surgical outcomes and the post-operative posture in corrective spinal surgery. The purpose of the study is to develop and validate A RBSM of the lumbar spine and spinal instrument model, which can simulate the interface between the pedicle screws and vertebra. The model was used to determine which level sustain the maximum pull-out force under simulated clinical conditions.