Catastrophic Wear of an Acetabular Component Misdiagnosed as Total Hip Arthroplasty Dislocation.

Total hip arthroplasty constitutes the operation of the century, although not without complications, which require revision surgery due to loosening, infection, dislocation, and wear. Hereby, we report a rare case of acetabular shell wear misdiagnosed as a dislocation. Patients who underwent total hip arthroplasty with ultra-high molecular weight polyethylene are more vulnerable to excessive wear, and close monitoring can prevent this catastrophic sequence. Timely and accurate diagnosis is mandatory to avoid any unnecessary interventions, such as useless reduction attempts. An anteroposterior radiograph is valuable, although computed tomography can settle the diagnosis with accuracy. Evaluation of any previous radiographic examination is very helpful to highlight any differences. Metal debris shown in the joint space, the bubble sign, and also the eccentric location of the prosthetic head are very helpful signs of the catastrophic wear presented to the X-rays. Since late onset dislocations are rare, orthopedic surgeons should be aware that catastrophic wear of the polyethylene and subsequently the acetabular shell can be presented as a late onset dislocation or protrusion. Furthermore, arthroplasty surgeons should adequately monitor patients who underwent hip arthroplasty with this particular polyethylene type.