Magnetic Resonance Imaging Findings in Painful Metal-On-Metal Hips

A Prospective Study

Shiraz A. Sabah, BSc,* Adam W.M. Mitchell, FRCR,y Johann Henckel, MRCS,z Ann Sandison, MRCPath,§ John A. Skinner, FRCS(Orth),• and Alister J. Hart, FRCSG(Orth)z

*Imperial College London, London, UK; y Department of Radiology, Charing Cross Hospital, London, UK; z Department of Musculoskeletal Surgery, Charing Cross Hospital, London, UK; §Department of Histopathology, Charing Cross Hospital, London, UK; •Department of Orthopaedics, Charing Cross Hospital, London, UK; and b Imperial College Healthcare NHS Trust, London, UK.

The Journal of Arthroplasty Vol. 26 No. 1 2011

Abstract: Metal artifact reduction sequence magnetic resonance imaging findings are reported in a prospective series of 31 patients with unexplained painful metal-on-metal (MOM) hips. The abnormalities identified were fluid collection (20 patients), solid mass (2 patients), moderate to severe muscle atrophy (23 patients), and muscle edema (8 patients). In conclusion, soft tissue lesions and muscle atrophy appear to be prevalent in unexplained painful MOM hips. Metal artifact reduction sequence magnetic resonance imaging may be useful to diagnose and monitor at-risk hips but requires validation in well-functioning MOM hips before it can guide clinical decision making.