Magnetic resonance imaging of joint replacements.

An increasing number of joint replacements are being performed annually. Complications of joint arthroplasty are diverse and may involve the hardware as well as osseous and soft tissue components. Although modalities such as conventional radiography and scintigraphy remain the mainstay of radiological investigation, in some cases these traditional methods of imaging may be negative or underestimate the extent of disease. Magnetic resonance imaging (MRI) has been considered of limited benefit following arthroplasty because of severe image degradation caused by metallic components. However, with modification of pulse sequences, artifact reduction and improved visualization of periprosthetic tissues are achievable, enabling a comprehensive assessment of articular and nonarticular pathologies. The common artifacts in the presence of orthopedic hardware, optimization of pulse sequences to minimize metal-related artifacts, and the clinical uses of MRI following joint replacement, particularly with regard to total hip arthroplasty, total knee arthroplasty, and shoulder arthroplasty, are reviewed.