Motion Analysis System after Total Hip Arthroplasty by using the Patient-Specific 4-dimensional Musculoskeletal Model

Abstract

We constructed a 4-dimensional musculoskeletal model for patients having had total hip arthroplasty (THA), which aims to simulate the movement of the patient's inner body structure and estimates the complications after THA. This model reflects the patient-specific characteristics of the bone geometry, implant alignment and the characteristics of the movement. In order to estimate the direction of the muscle force and the length of the muscles, we have developed a string-typed muscle model representing the route of the muscles. The strings expand and contract according to the movement of the origin and insertion location of the muscle. We developed models of the seven muscles related to the movement of the hip joint. By using this model, clinicians can predict the potential for dislocation or recognize the causes of dislocation, including the influence of the muscles.