Range of motion after total hip arthroplasty: experimental verification of the analytical simulator

Dislocation following total hip replacement surgery represents a significant cause of early failure, incurring additional medical costs. The causes of dislocation are multifactorial and are related to surgical approach, soft tissue tension, prosthetic design, and most important, orientation of components. This paper describes experimental verification of our analytical approach for predicting implant impingement and dislocation. Once fully developed and tested, this analytical methodology could be used as a preoperative simulation tool that will present surgeons with information about the “safe” range of motion and chance of dislocation based on selected component positions, allowing for the surgical plan to be optimized based on this criterion. Coupled with a computer-assisted clinical system for precise implant positioning, this approach could significantly reduce the postoperative risk of dislocation, maximize “safe” range of motion and minimize impingement.