MRI for an Acute Secondary Site Complication in Post-arthroplasty Management: Narrative Review of Safety Concerns for an Implanted Hip and Knee Joint

Arthroplasty in the elderly may present with acute or late-onset complications unrelated to an implanted arthroplasty joint. Magnetic resonance imaging (MRI) evaluation of an acute onset complication in the immediate post-arthroplasty scenario presents safety concerns. An arthroplasty surgeon's dilemma relates to the loosening, heating, or migration of implanted hip or knee joints. We present a representational case scenario for discussion. A hip arthroplasty patient presenting with hemiplegia in the immediate postoperative period necessitated an MRI evaluation for the brain with an additional angiogram. A knee arthroplasty patient presenting with lower limb weakness in the immediate postoperative period necessitated an MRI evaluation of the brain. Loosening of surgical metallic clips used for wound closure and the instability or loosening of recently implanted hip and knee joints pose significant safety concerns for the arthroplasty surgeon. The confirmatory diagnosis of the secondary site complication in the acute post-arthroplasty perioperative period, however, allowed the allied super-specialist to plan the management protocol. A review of the literature suggests that the use of nonferromagnetic elements in implanted joints with the use of cement or the press-fit method of implantation during arthroplasty has high safety margins. The staples used for wound closure have significant strength to hold the wound without any disruption or dehiscence during the MRI imaging. The metallic artifacts associated with an implanted joint do not interfere in the evaluation of the secondary site MRI. MRI can be safely done in a well-fixed joint of non-ferromagnetic elements. The review of literature also suggests that MRI can be done even in the presence of skin staples for the assessment of an acute secondary site complication in a post-arthroplasty patient. The risk-to-benefit ratio though needs to be applied for imaging a secondary site.