Early failure of a Birmingham resurfacing hip replacement with lymphoreticular spread of metal debris: pre-operative diagnosis with MR.

Metal-on-metal hip replacements are the subject of much current debate. There is some evidence that there may be a hypersensitivity reaction, specific to metal-on-metal total hip replacements (THRs), which is associated with early failure of these prostheses. It has to date only been described in total replacements and not in metal-on-metal hip resurfacing. We present the case of a 68-year-old man who underwent bilateral metal-on-metal hip resurfacing for osteoarthrosis. The patient presented 6 months after surgery with pain and lateral thigh swelling. Pre-operative ultrasound and MRI demonstrated findings similar to those described in early failing metal-on-metal THRs, as well as evidence of lymphoreticular spread of metal debris. The operative findings included extensive aseptic soft-tissue necrosis. Histology revealed necrosis and a dense perivascular lymphocytic infiltrate along with metal debris within sinus histiocytes. The surgical, radiological and histological findings are similar to soft-tissue reactions described in metal-on-metal THRs.