Indications for MARS-MRI in Patients Treated With Articular Surface Replacement XL Total Hip Arthroplasty

Abstract

Level II, diagnostic study.

Letter to the Editor on “Indications for MARS-MRI in Patients Treated With Articular Surface Replacement XL Total Hip Arthroplasty”

“…The authors have used the area under the curve (AUC) to assess the discriminatory ability of their new algorithm (AUC of 50% ¼ a nondiscriminatory algorithm; AUC of 100% ¼ algorithm with perfect discrimination). Although their new algorithm had the highest AUC of the other guidelines assessed, it was still only 63% [1]. This does not therefore represent a clinically useful algorithm, especially given the context of the clinical problem.…”

“…However, it is important to keep in mind that the questions posed must be clinically relevant. I would argue in this particular study of ASR XL implants by Connelly et al [1] that the research question is not clinically relevant, as is the case for their other recent paper on ASR hip resurfacings [5].…”

“…The main reason they state relates to the extra cost of these investigations; however, I would propose that this can largely be ignored given the catastrophic failure of this implant design and the need to first protect our patients from future problems. Furthermore, the authors claim that the algorithm they developed was "highly sensitive and specific" and that it "outperformed existing national guidelines" [1]. From the data presented I would question these bold statements.…”

“…I read the recent study by Connelly et al [1] with interest. The high short-term failure rate of metal-on-metal hip arthroplasty (MoMHA) has led to almost all patients requiring regular surveillance.…”

“…It is therefore unclear why the studies by Connelly et al [1,5] have investigated how to rationalize the use of metal artefact reduction sequence magnetic resonance imaging (MARS-MRI) imaging in this group of patients with high risk withdrawn implants. The main reason they state relates to the extra cost of these investigations; however, I would propose that this can largely be ignored given the catastrophic failure of this implant design and the need to first protect our patients from future problems.…”