BACKGROUND: The prevalence of pseudotumors in patients with large-head metal-on-metal (MOM) THA has been the subject of implant recalls and warnings from various regulatory agencies. To date, there is no consensus on whether ultrasound or MRI is superior for the detection of pseudotumors. QUESTIONS/PURPOSES: We prospectively compared ultrasound to MRI for pseudotumor detection in an asymptomatic cohort of patients with MOM THAs. We also compared ultrasound to MRI for assessment of pseudotumor growth and progressive soft tissue involvement at a 6-month interval. METHODS: We enrolled 40 patients with large-head MOM THAs in the study. The mean age was 54 years (range, 34-76 years). The mean time from surgery was 54 months (range, 40-81 months). There were 28 men and 12 women. All patients underwent ultrasound and MRI using slice encoding for metal artifact correction. The gold standard was defined as follows: if both ultrasound and MRI agreed, this was interpreted as concordant and the result was considered accurate. RESULTS: Ultrasound and MRI agreed in 37 of 40 patients (93%). The prevalence of pseudotumors was 31% (12 of 39) in our cohort. Twenty-three of 39 patients (59%) had completely normal tests and four (10%) had simple fluid collections. Ultrasound had a sensitivity of 100% and specificity of 96% while MRI had a sensitivity of 92% and specificity of 100%. CONCLUSIONS: A negative ultrasound rules out pseudotumor in asymptomatic patients as this test is 100% sensitive. Given its lower cost, we recommend ultrasound as the initial screening tool for pseudotumors.
BACKGROUND: The prevalence of pseudotumors in patients with large-head metal-on-metal (MOM) THA has been the subject of implant recalls and warnings from various regulatory agencies. To date, there is no consensus on whether ultrasound or MRI is superior for the detection of pseudotumors. QUESTIONS/PURPOSES: We prospectively compared ultrasound to MRI for pseudotumor detection in an asymptomatic cohort of patients with MOM THAs. We also compared ultrasound to MRI for assessment of pseudotumor growth and progressive soft tissue involvement at a 6-month interval. METHODS: We enrolled 40 patients with large-head MOM THAs in the study. The mean age was 54 years (range, 34-76 years). The mean time from surgery was 54 months (range, 40-81 months). There were 28 men and 12 women. All patients underwent ultrasound and MRI using slice encoding for metal artifact correction. The gold standard was defined as follows: if both ultrasound and MRI agreed, this was interpreted as concordant and the result was considered accurate. RESULTS: Ultrasound and MRI agreed in 37 of 40 patients (93%). The prevalence of pseudotumors was 31% (12 of 39) in our cohort. Twenty-three of 39 patients (59%) had completely normal tests and four (10%) had simple fluid collections. Ultrasound had a sensitivity of 100% and specificity of 96% while MRI had a sensitivity of 92% and specificity of 100%. CONCLUSIONS: A negative ultrasound rules out pseudotumor in asymptomatic patients as this test is 100% sensitive. Given its lower cost, we recommend ultrasound as the initial screening tool for pseudotumors.
Authors: G Grammatopoulos; G Grammatopolous; H Pandit; Y-M Kwon; R Gundle; P McLardy-Smith; D J Beard; D W Murray; H S Gill Journal: J Bone Joint Surg Br Date: 2009-08
Authors: Helen Anderson; Andoni Paul Toms; John G Cahir; Richard W Goodwin; James Wimhurst; John F Nolan Journal: Skeletal Radiol Date: 2010-07-25 Impact factor: 2.199
Authors: Kevin J Bozic; Steven Kurtz; Edmund Lau; Kevin Ong; Vanessa Chiu; Thomas P Vail; Harry E Rubash; Daniel J Berry Journal: J Bone Joint Surg Am Date: 2009-07 Impact factor: 5.284
Authors: Christopher S J Fang; Paul Harvie; Christopher L M H Gibbons; Duncan Whitwell; Nicholas A Athanasou; Simon Ostlere Journal: Skeletal Radiol Date: 2008-05-14 Impact factor: 2.199
Authors: H Pandit; S Glyn-Jones; P McLardy-Smith; R Gundle; D Whitwell; C L M Gibbons; S Ostlere; N Athanasou; H S Gill; D W Murray Journal: J Bone Joint Surg Br Date: 2008-07
Authors: Andrea Lazik; Stefan Landgraeber; Patrick Schulte; Oliver Kraff; Thomas C Lauenstein; Jens M Theysohn Journal: Skeletal Radiol Date: 2015-03-25 Impact factor: 2.199
Authors: Brett K J Kilb; Andrew P Kurmis; Michael Parry; Karen Sherwood; Paul Keown; Bassam A Masri; Clive P Duncan; Donald S Garbuz Journal: Clin Orthop Relat Res Date: 2018-02 Impact factor: 4.176
Authors: Nicholas B Frisch; Nolan M Wessell; Kevin Taliaferro; Marnix Van Holsbeeck; Craig D Silverton Journal: Skeletal Radiol Date: 2017-02-15 Impact factor: 2.199
Authors: Isabelle Catelas; Eric A Lehoux; Ian Hurda; Stephen J Baskey; Luca Gala; Ryan Foster; Paul R Kim; Paul E Beaulé Journal: Clin Orthop Relat Res Date: 2015-09-01 Impact factor: 4.176