Arthrography of the prosthesetized painful hip: the importance of imaging and functional testing

Thirty-four patients with painful prosthesetized hips were submitted to arthrography in order to evaluate the correlation between pain and the anatomical situation between the implants and the host bone. By injecting a local anaesthetic together with the contrast medium it was possible to perform functional tests comprising passive movements of the hip and full weightbearing for at least 5 minutes in order to ascertain whether or not the pain persisted. This yielded different results varying from total relief to persistence, depending on the type of mobilisation demonstrated by arthrography. In particular, pain was reduced in cases of mobilisation of the acetabular component, and persisted when mobilisation was in the femoral component. A correlation between functional testing, arthrography and bacteriological examination for possible low grade infection allowed for a closer study of the origin of pain, and more accurate planning of surgery when re-prosthesetization was being considered.