MoM hip prostheses: The FDA notes that in the symptomatic patient following insertion of a MoM prosthesis, radiographs in conjunction with nonimaging information, may disclose the need for revision [44]. Metallosis resulting from severe wear of a metal on metal articulation may occasionally be identified on radiographs [64]. Component position can be assessed [65]. Matharu et al [54] found hips with resurfacing arthroplasties and symptomatic pseudotumors were more likely than those without pseudotumors to have abnormal radiographs (80.0% compared with 63.4%). Radiographic features Imaging After Total Hip Arthroplasty that predicted revision for pseudotumors included high inclination, acetabular or femoral osteolysis, and acetabular loosening. In that study, 20% of hip resurfacing prostheses with pseudotumors at revision surgery had normal radiographic features [54]. Based on these findings, Matharu et al [54] concluded that radiographs were important and useful in all follow-up protocols to assess MoM hip resurfacing prostheses. Petscavage-Thomas and Ha [49] concluded on literature review that cross-sectional imaging, particularly MRI, is still beneficial even in the presence of normal radiographs. US Hip Non-MoM hip prostheses: There is insufficient evidence to support the use of US of the hip as the initial imaging modality for the patient with a symptomatic non-MoM prosthesis. US for MoM hip prostheses: In a series of 82 hips (82 patients) undergoing revision of MoM prostheses, Lainiala et al [51] found the sensitivity of US examination to be 83% with a specificity of 92% for pseudotumors in the trochanteric region and a sensitivity of 79% and a specificity of 94% for identifying pseudotumors in the iliopsoas region. Matharu et al [66] studied a series of 40 MoM hip resurfacing arthroplasties (39 patients) undergoing revision surgery who had preoperative imaging with both US and MARS-MRI.
Imaging after Total Hip Arthroplasty PCAs. MoM hip prostheses: The FDA notes that in the symptomatic patient following insertion of a MoM prosthesis, radiographs in conjunction with nonimaging information, may disclose the need for revision [44]. Metallosis resulting from severe wear of a metal on metal articulation may occasionally be identified on radiographs [64]. Component position can be assessed [65]. Matharu et al [54] found hips with resurfacing arthroplasties and symptomatic pseudotumors were more likely than those without pseudotumors to have abnormal radiographs (80.0% compared with 63.4%). Radiographic features Imaging After Total Hip Arthroplasty that predicted revision for pseudotumors included high inclination, acetabular or femoral osteolysis, and acetabular loosening. In that study, 20% of hip resurfacing prostheses with pseudotumors at revision surgery had normal radiographic features [54]. Based on these findings, Matharu et al [54] concluded that radiographs were important and useful in all follow-up protocols to assess MoM hip resurfacing prostheses. Petscavage-Thomas and Ha [49] concluded on literature review that cross-sectional imaging, particularly MRI, is still beneficial even in the presence of normal radiographs. US Hip Non-MoM hip prostheses: There is insufficient evidence to support the use of US of the hip as the initial imaging modality for the patient with a symptomatic non-MoM prosthesis. US for MoM hip prostheses: In a series of 82 hips (82 patients) undergoing revision of MoM prostheses, Lainiala et al [51] found the sensitivity of US examination to be 83% with a specificity of 92% for pseudotumors in the trochanteric region and a sensitivity of 79% and a specificity of 94% for identifying pseudotumors in the iliopsoas region. Matharu et al [66] studied a series of 40 MoM hip resurfacing arthroplasties (39 patients) undergoing revision surgery who had preoperative imaging with both US and MARS-MRI.