[Unusual late complications following total hip endoprosthesis]

A cementless total hip replacement was implanted in a 52-year-old male patient with coxarthrosis. Rapid cranial migration of the cup and ectopic ossification were subsequently observed. Five years after the original operation, revisional arthroplasty had to be performed to replace the cup. At surgery a large amount of granulomatous tissue and the tip of a deep drainage tube were found. Interposed between the polyethylene inlay and the femoral head of the prosthesis, the drain had not been visible on any of the radiographic controls. The X-ray control performed immediately after the first procedure revealed that the drain had been slung around the neck of the prosthesis stem, a procedure preferred by some surgeons. When the drain was removed, the tip must have been caught between the polyethylene inlay and the femoral head of the prosthesis. It is not clear whether the loosening of the cup was ultimately caused by the increased wear due to the presence of the drain tip. However, in light of this finding we no longer sling the drain around the prosthesis shaft, but lay it along the neck of the femoral component in the same direction as it is routed out transcutaneously.