TY - JOUR
T1 - Magnetic resonance imaging findings in symptomatic versus symptomatic subjects following metal-on-metal hip resurfacing Arthroplasty
AU - Nawabi, Danyal H.
AU - Hayter, Catherine L.
AU - Su, Edwin P.
AU - Koff, Matthew F.
AU - Perino, Giorgio
AU - Gold, Stephanie L.
AU - Koch, Mevin M.
AU - Potter, Hollis G.
N1 - Funding Information:
GE Healthcare provided funding for the scanning of asymptomatic subjects. The fellowship training for one of the authors (D.H.N.) was supported by the British Hip Society Charnley Latta Fund and the Norman Capener Award.
PY - 2013/5/15
Y1 - 2013/5/15
N2 - Background: Although pseudotumors have been reported at the sites of well-functioning and painful metal-on-metal hip prostheses, there are no objective data on the magnitude of the adverse reaction. This observational study was performed to investigate the ability of modified magnetic resonance imaging (MRI) to detect and quantify adverse synovial responses in symptomatic and asymptomatic subjects following metal-on-metal hip resurfacing. We hypothesized that the magnitude of the synovial reactions would be greater in symptomatic patients. Methods: Sixty-nine patients (seventy-four hips) with hip resurfacing were divided into three groups: asymptomatic (twenty-two hips), symptomatic with a mechanical cause (twenty), and unexplained pain (thirty-two). The volume of synovitis was calculated on MRI for all patients. Results: Synovitis was detected in fifteen asymptomatic hips (68%), fifteen (75%) with symptoms with a mechanical causes, and twenty-five (78%) with unexplained pain. The mean volume (and standard deviation) of the synovitis in these groups was 5 ± 7 cm3, 10 ± 16 cm3, and 31 ± 47 cm3, respectively. The coefficient of repeatability between the examiners was 1.8 cm3 for measurement of synovitis. Of the thirteen subjects with revision arthroplasty, six had an adverse local tissue reaction. This subgroup had the highest volumes of synovitis on MRI. Conclusions: An adverse synovial reaction was detected on MRI in both symptomatic and asymptomatic subjects. We found a larger volume of synovitis in symptomatic patients; this increase reached significance only in the group with an adverse local tissue reaction. Synovial volume on MRI may be a valuable marker in the longitudinal assessment of asymptomatic patients with a metal-on-metal hip resurfacing and in identifying patients with adverse local tissue reaction. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
AB - Background: Although pseudotumors have been reported at the sites of well-functioning and painful metal-on-metal hip prostheses, there are no objective data on the magnitude of the adverse reaction. This observational study was performed to investigate the ability of modified magnetic resonance imaging (MRI) to detect and quantify adverse synovial responses in symptomatic and asymptomatic subjects following metal-on-metal hip resurfacing. We hypothesized that the magnitude of the synovial reactions would be greater in symptomatic patients. Methods: Sixty-nine patients (seventy-four hips) with hip resurfacing were divided into three groups: asymptomatic (twenty-two hips), symptomatic with a mechanical cause (twenty), and unexplained pain (thirty-two). The volume of synovitis was calculated on MRI for all patients. Results: Synovitis was detected in fifteen asymptomatic hips (68%), fifteen (75%) with symptoms with a mechanical causes, and twenty-five (78%) with unexplained pain. The mean volume (and standard deviation) of the synovitis in these groups was 5 ± 7 cm3, 10 ± 16 cm3, and 31 ± 47 cm3, respectively. The coefficient of repeatability between the examiners was 1.8 cm3 for measurement of synovitis. Of the thirteen subjects with revision arthroplasty, six had an adverse local tissue reaction. This subgroup had the highest volumes of synovitis on MRI. Conclusions: An adverse synovial reaction was detected on MRI in both symptomatic and asymptomatic subjects. We found a larger volume of synovitis in symptomatic patients; this increase reached significance only in the group with an adverse local tissue reaction. Synovial volume on MRI may be a valuable marker in the longitudinal assessment of asymptomatic patients with a metal-on-metal hip resurfacing and in identifying patients with adverse local tissue reaction. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
UR - http://www.scopus.com/inward/record.url?scp=84879775931&partnerID=8YFLogxK
U2 - 10.2106/JBJS.K.01476
DO - 10.2106/JBJS.K.01476
M3 - Article
C2 - 23677356
AN - SCOPUS:84879775931
SN - 0021-9355
VL - 95
SP - 895
EP - 902
JO - Journal of Bone and Joint Surgery
JF - Journal of Bone and Joint Surgery
IS - 10
ER -