Radiostereometric Analysis: The Hip

Abstract

RSA is the most accurate technique available to measure implant migration following total hip arthroplasty. Implant migration is an important predictor of long term fixation of uncemented and cemented femoral and acetabular components. Especially with a more recent interest in uncemented fixation continuous migration after 6 months intervals might be evidence of inadequate bone ingrowths. RSA has the benefit of picking up continous migration long before clinical failure will be evident and is therefore considered to be perfectly suited to evaluate new implant designs and implant coatings. It can also be used to evaluate the impact of hard surface bearings including metal-on-metal and ceramic-on-ceramic on bone in-growth and migration of uncemented components. In the future RSA might be an interesting tool to pick up decreased rates of aseptic loosening with the use of computer navigation within short term follow-ups.