Eccentric Wear of Polyethylene Liner in a Bipolar Hemiarthroplasty Leading to a Revision Total Hip Arthroplasty.

INTRODUCTION

Aseptic component loosening is a common cause of revision surgery post a hip replacement surgery. Polyethylene wear is a known cause of this loosening which results due to osteolysis of the bone stock surrounding the implant. Most patients have catastrophic wear through failure which manifests as discomfort, noise in the joint, and eccentric femoral head location with increasing leg length discrepancy. However, sometimes clinical presentation may be quite late while liner erosion leads to subluxation of the femoral head which is seen on radiographic imaging. We present a case of rapid polyethylene liner wear leading to femoral head subluxation in a case of bipolar hemiarthroplasty of the hip.

CASE REPORT

A 70-year-old female patient underwent a bipolar hemiarthroplasty of the right hip for a transcervical neck of femur fracture 5 years ago. She presented to us with a subluxated femoral head within the cup on radiographs with clinical limp and pain. She was taken up for revision total hip replacement surgery.

CONCLUSION

Routine clinical and radiographic follow-ups should be done post-total or hemi hip replacement surgeries to catch polyethylene wear signs and symptoms in the early stage which could then be treated with a simple liner exchange rather than an extensive revision surgery. Whenever dealing with osteoporotic bone, we need to keep a low threshold for extended trochanteric osteotomy for cement removal from the femoral canal.