Osteolysis: Osteolysis due to wear typically results in expansile well-defined lucent lesions. Helical CT with metal- artifact reduction is more sensitive than radiographs for identifying and quantifying osteolysis after THA [125]. Walde et al [126] confirmed CT to be more sensitive than radiographs for periacetabular lesion detection in a cadaver model (74.7% sensitivity for CT, 51.7% sensitivity for radiographs). Comparison of CT and MRI Imaging After Total Hip Arthroplasty demonstrated that for lesions of all sizes, CT was less sensitive than MRI (CT, 74.7% sensitive and MRI, 95.4% sensitive) [126]. Most CT examinations of prostheses are not routinely performed with either IV or intraarticular contrast, particularly now that MAR algorithms for CT have been introduced [22,23]. Fluoride PET/CT Skull Base To Mid-Thigh Although most investigations have focused on the ability of fluoride PET/CT to differentiate between aseptic loosening and periprosthetic infection, normal asymptomatic controls were included in several of them. Kobayashi et al [98] reported that increased periprosthetic uptake was present in all cases of loosening and infection but in only 1 (3.7%) of 27 controls. Kumar et al [99] reported that 10 of 12 (83.3%) asymptomatic hip prostheses demonstrated no periprosthetic uptake, whereas periprosthetic uptake was present around all 28 aseptically loosened and all 16 infected devices. Choe at al [97] reported that 3 of 17 (17.6%) control hip prostheses demonstrated minor periprosthetic uptake and the mean SUVmax (4) was significantly less than that of aseptic loosening (7) and infection (11); P < . 01 and P < . 001, respectively. Image-Guided Anesthetic Injection of Hip Intraarticular anesthetic has been used to evaluate painful THAs, primarily to differentiate referred pain (especially from the spine) from pain originating in the hip [127]. Significant pain relief after intraarticular anesthetic injection suggests an intraarticular cause [128,129].
Imaging after Total Hip Arthroplasty PCAs. Osteolysis: Osteolysis due to wear typically results in expansile well-defined lucent lesions. Helical CT with metal- artifact reduction is more sensitive than radiographs for identifying and quantifying osteolysis after THA [125]. Walde et al [126] confirmed CT to be more sensitive than radiographs for periacetabular lesion detection in a cadaver model (74.7% sensitivity for CT, 51.7% sensitivity for radiographs). Comparison of CT and MRI Imaging After Total Hip Arthroplasty demonstrated that for lesions of all sizes, CT was less sensitive than MRI (CT, 74.7% sensitive and MRI, 95.4% sensitive) [126]. Most CT examinations of prostheses are not routinely performed with either IV or intraarticular contrast, particularly now that MAR algorithms for CT have been introduced [22,23]. Fluoride PET/CT Skull Base To Mid-Thigh Although most investigations have focused on the ability of fluoride PET/CT to differentiate between aseptic loosening and periprosthetic infection, normal asymptomatic controls were included in several of them. Kobayashi et al [98] reported that increased periprosthetic uptake was present in all cases of loosening and infection but in only 1 (3.7%) of 27 controls. Kumar et al [99] reported that 10 of 12 (83.3%) asymptomatic hip prostheses demonstrated no periprosthetic uptake, whereas periprosthetic uptake was present around all 28 aseptically loosened and all 16 infected devices. Choe at al [97] reported that 3 of 17 (17.6%) control hip prostheses demonstrated minor periprosthetic uptake and the mean SUVmax (4) was significantly less than that of aseptic loosening (7) and infection (11); P < . 01 and P < . 001, respectively. Image-Guided Anesthetic Injection of Hip Intraarticular anesthetic has been used to evaluate painful THAs, primarily to differentiate referred pain (especially from the spine) from pain originating in the hip [127]. Significant pain relief after intraarticular anesthetic injection suggests an intraarticular cause [128,129].