Métodos radiológicos para evaluación de polietileno en artroplastia de cadera.

Richard W. McCalden, MD, FRCSC1, Douglas D. Naudie, MD, FRCSC1, Xunhua Yuan, PhD2 and Robert B. Bourne, MD, FRCSC1 1 Division of Orthopaedic Surgery, London Health Sciences Centre, University Campus, 339 Windermere Road, London, Ontario, Canada N6A 5A5. E-mail address for R.W. McCalden: richard.mccalden@lhsc.on.ca. E-mail address for D.D. Naudie: dnaudie@mac.com. E-mail address for R.B. Bourne: robert.bourne@lhsc.on.ca 2 Medical Imaging Laboratory, Robarts Research Institute, 100 Perth Drive, London, Ontario, Canada N6A 5K8. E-mail address: xyuan@imaging.robarts.ca

Investigation performed at the Division of Orthopaedic Surgery, London Health Sciences Centre, London, Ontario, Canada

The authors did not receive grants or outside funding in support of their research or preparation of this manuscript. They did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the authors are affiliated or associated.

All wear-measurement techniques assess femoral head penetration and therefore cannot distinguish between true polyethylene wear and bedding-in. Multiple wear measurements that are made at different time-intervals after bedding-in has occurred are required to determine the true wear rate.

Computer-assisted edge-detection techniques offer improved accuracy and precision compared with manual techniques and appear to be ideally suited for the retrospective and prospective examination of large groups of patients with intermediate to long-term radiographic follow-up (more than five years).

While radiostereometric analysis offers improved accuracy and precision compared with computer-assisted edge-detection techniques, widescale clinical application is limited because of its relative expense, the required expertise, and the fact that it can only be used in a prospective fashion.