The evaluation of manual 2D/3D registration technology and its potential to deduce prosthetic wear in patients with metalon‐metal hip resurfacing prostheses

Abstract

Metal‐on‐metal hip resurfacing arthroplasty (MoMHRA) has been a popular alternative treatment for young patients with hip osteoarthritis. Despite its advantages over total hip arthroplasty, MoMHRA remains controversial. Malpositioning of the metal components can result in abnormal levels of blood metal ions in the patient; and yet, post‐operative management using 2D x‐rays contain high variance leading to poor detection of prosthetic wear. The purpose of this study is to determine whether 2D/3D registration technology can generate accurate acetabular implant measurements; and, whether 3D data can correlate to metal ion counts to deduce wear. Virtual 3D pelvic models (n=72) and acetabular implants were manually superimposed over 2D x‐ray images according to anatomical landmarks to measure acetabular inclination and version angles. CT models were generated for validation. No significant difference was reported between 2D vs. 3D vs. CT data, suggesting measurements were similar to the results of the gold standard CT model; although 3D measurements were more precise compared to 2D. Furthermore, there was no significant correlation in either 2D or 3D measurements compared to metal ion levels, although a stronger trend is demonstrated in 3D measurements. The findings of this study are inconsistent with the reports in literature and so further investigation is required. Supported by Queen's Graduate Award.