Imaging Evaluation and Risk Factors for Hip Instability

Initial Imaging and Assessment

Radiographs should be the first imaging modality for assessment of a symptomatic hip prosthesis, helping evaluate component positioning, which is critical in assessing instability risk 1
Serial radiographs are useful but may be affected by differences in hip flexion or rotation, and are used for comparison studies 1

CT with Metal Artifact Reduction (MAR) provides detailed assessment of component position and potential complications, as recommended by clinical guidelines 2
MRI with Metal Artifact Reduction Sequences (MARS) enables evaluation of soft tissues around the prosthetic hip, particularly useful for assessing the pseudocapsule and tendons, according to the American College of Radiology 3
Ultrasound is valuable for assessing soft tissues adjacent to hip arthroplasties without being affected by prosthetic artifacts, as suggested by the American College of Radiology 3

The American College of Radiology suggests that misdiagnosis risk is high in patients with hip prostheses, where extracapsular disease associated with adverse reactions to metal debris (ARMD) could be misinterpreted as trochanteric bursitis or other conditions 4