Establishing a range of motion boundary for total hip arthroplasty.

Range of motion of the hip joint is a major contributor to dislocation post total hip replacement. Impingement is often treated as a surrogate for dislocation and occurs--prosthetically--when the neck of the femoral component contacts with the rim of the pelvic acetabular cup. This impingement is caused by movement of the leg during activities of daily living. This article analyses hip joint range of motion and its implication for impingement. A systematic literature review was undertaken with the purpose of establishing a range of motion benchmark for total hip replacement. This paper proposes a method by which a three-dimensional range of motion boundary established from the literature can be presented. The nominal boundary is also validated experimentally using a number of configurations of a neutral hip joint coordinate frame.