MRI Hip MRI for asymptomatic non-MoM hips: MRI is generally not indicated in routine follow-up of asymptomatic patients with non-MoM prostheses. However, the MRI findings in asymptomatic patients are being investigated [19,31-33]. MARS-MRI for asymptomatic MoM prostheses: Pseudotumors consistent with ARMD have been reported on MRI in patients without pain following MoM arthroplasties [6,33-38]. Thus, MRI may be beneficial in this group. In a series of MoM hip resurfacing arthroplasties, clinical outcomes and radiographic screening underestimated the presence of pseudotumors and supported the use of MRI for screening [38]. Similarly, Koff et al [33] performed 4 yearly MRI examinations of patients with surface replacement prostheses and found evidence of ALTRs in high- functioning individuals without pain. They concluded that MRI should be considered as part of the routine patient follow-up protocol to allow early detection and follow-up of ALTRs. In 2 series, comparison of MRI results to histologic findings showed the sensitivity of MRI for pseudotumors to be 85% and 71%, respectively, and the specificity to be 59% and 87%, respectively [39,40]. Sensitivity was greater when the MRI examination was performed within 3 months of the revision surgery (88%) [39]. Imaging After Total Hip Arthroplasty Combined US and MARS-MRI studies: Comparison to surgical results suggests combining US and MARS-MRI improves accuracy. Small numbers of lesions detected on US are not visible on MRI, and some lesions seen on MRI are not apparent on US [35,36,41]. Radiography Hip Follow-up radiographs for asymptomatic non-MoM total hip prostheses: Radiographs have been the imaging mainstay for following THA [42]. Review of serial radiographs is useful for identifying subtle changes, emphasizing the need for baseline radiographs.
Imaging after Total Hip Arthroplasty PCAs. MRI Hip MRI for asymptomatic non-MoM hips: MRI is generally not indicated in routine follow-up of asymptomatic patients with non-MoM prostheses. However, the MRI findings in asymptomatic patients are being investigated [19,31-33]. MARS-MRI for asymptomatic MoM prostheses: Pseudotumors consistent with ARMD have been reported on MRI in patients without pain following MoM arthroplasties [6,33-38]. Thus, MRI may be beneficial in this group. In a series of MoM hip resurfacing arthroplasties, clinical outcomes and radiographic screening underestimated the presence of pseudotumors and supported the use of MRI for screening [38]. Similarly, Koff et al [33] performed 4 yearly MRI examinations of patients with surface replacement prostheses and found evidence of ALTRs in high- functioning individuals without pain. They concluded that MRI should be considered as part of the routine patient follow-up protocol to allow early detection and follow-up of ALTRs. In 2 series, comparison of MRI results to histologic findings showed the sensitivity of MRI for pseudotumors to be 85% and 71%, respectively, and the specificity to be 59% and 87%, respectively [39,40]. Sensitivity was greater when the MRI examination was performed within 3 months of the revision surgery (88%) [39]. Imaging After Total Hip Arthroplasty Combined US and MARS-MRI studies: Comparison to surgical results suggests combining US and MARS-MRI improves accuracy. Small numbers of lesions detected on US are not visible on MRI, and some lesions seen on MRI are not apparent on US [35,36,41]. Radiography Hip Follow-up radiographs for asymptomatic non-MoM total hip prostheses: Radiographs have been the imaging mainstay for following THA [42]. Review of serial radiographs is useful for identifying subtle changes, emphasizing the need for baseline radiographs.