Date Published: May 10, 2011
Publisher: SAGE-Hindawi Access to Research
Author(s): Conor P. McGrory, Brian J. McGrory.
Demonstrable anterior subluxation of the femoral head after a total hip arthroplasty is a rare complication and is usually transient. Both a case of recurrent subluxation and a case of chronic subluxation are described in this paper, each one presenting with unexpected femoral head eccentricity in the acetabulum on radiograph. We show how this unusual complication can be successfully identified and treated.
Instability after total hip replacement (THA) occurs infrequently and leads in most cases to hip dislocation. In rare cases, instability presents as transient subluxation [1–3]. A patient reports a sound or click and often has a sense of giving way or apprehension. Dislocation and subluxation of the hip after THA normally occur in the first three postoperative months, but cases of late instability are not uncommon [4, 5].
We reviewed two cases of patients who presented with apparent eccentric polyethylene wear and pain, after contemporary THA. In both situations the acetabular component was positioned in excessive abduction. After direct lateral radiograph confirmed femoral head subluxation and examination under fluoroscopy with the leg internally rotated confirmed reduction, revision surgery was offered. Both patients underwent revision surgery to reposition the cup, and in both cases pain-free ambulation, without recurrent subluxation, was achieved after recovery.
This is the first report, to our knowledge, that documents the radiographic presentation and treatment of both chronic (patient 1) and intermittent (patient 2) anterior THA subluxations.
The corresponding author confirms that any research associated with this manuscript underwent ethics committee approval and the correct procedure was followed regarding releases and ethical research standards.