There is insufficient literature documenting an additional benefit of MRI with IV contrast, relative to noncontrast MRI, in this population. Radiographic Arthrography Hip Loosening: There is no recent relevant literature regarding the use of arthrography of the hip in the evaluation of component loosening. Older studies had suggested a selective role for arthrography for further analysis when there was hip pain and a question of loosening and negative or equivocal radiographs [135,136]. However, this examination appears to be little used currently. Variant 6: Evaluation of symptomatic hip arthroplasty patient with metal-on-metal prosthesis or findings suggesting trunnionosis. Question of adverse reaction to metal debris. Additional imaging following radiographs. Changes due to ARMD may occur months or years after surgery and can be symptomatic or asymptomatic [7,137]. The results of revision surgery may be poor, and early identification of soft tissue changes of ARMD is thought to be important to improve outcome [7,138]. Investigators have sought to identify clinical, laboratory (eg, cobalt and Imaging After Total Hip Arthroplasty chrome ion levels in the blood), and patient features that could identify patients with or likely to develop ARMD so that revision or close follow-up could be performed. These are outside the scope of this document. Imaging remains a critical resource although its optimal utilization is still being clarified. CT Hip Overall, CT is less able than MRI to detect changes associated with ARMD. Noncontrast CT may be considered following other imaging modalities to assess osteolysis. Robinson et al [134] found a sensitivity of 44% for CT in comparison with MARS-MRI for ARMD pseudotumor detection in patients with unexplained painful MoM prostheses. Also, the detected pseudotumors could not be classified as to structure using CT.
Imaging after Total Hip Arthroplasty PCAs. There is insufficient literature documenting an additional benefit of MRI with IV contrast, relative to noncontrast MRI, in this population. Radiographic Arthrography Hip Loosening: There is no recent relevant literature regarding the use of arthrography of the hip in the evaluation of component loosening. Older studies had suggested a selective role for arthrography for further analysis when there was hip pain and a question of loosening and negative or equivocal radiographs [135,136]. However, this examination appears to be little used currently. Variant 6: Evaluation of symptomatic hip arthroplasty patient with metal-on-metal prosthesis or findings suggesting trunnionosis. Question of adverse reaction to metal debris. Additional imaging following radiographs. Changes due to ARMD may occur months or years after surgery and can be symptomatic or asymptomatic [7,137]. The results of revision surgery may be poor, and early identification of soft tissue changes of ARMD is thought to be important to improve outcome [7,138]. Investigators have sought to identify clinical, laboratory (eg, cobalt and Imaging After Total Hip Arthroplasty chrome ion levels in the blood), and patient features that could identify patients with or likely to develop ARMD so that revision or close follow-up could be performed. These are outside the scope of this document. Imaging remains a critical resource although its optimal utilization is still being clarified. CT Hip Overall, CT is less able than MRI to detect changes associated with ARMD. Noncontrast CT may be considered following other imaging modalities to assess osteolysis. Robinson et al [134] found a sensitivity of 44% for CT in comparison with MARS-MRI for ARMD pseudotumor detection in patients with unexplained painful MoM prostheses. Also, the detected pseudotumors could not be classified as to structure using CT.