|
Year |
2002 |
|---|---|
|
Question Number |
91 |
|
Category |
Hip and Knee Reconstruction |
Question
Bipolar hip arthroplasty maintains a useful role in revision arthroplasty for which of the following conditions?
1- Pelvic discontinuity
2- Semental acetabular defects
3- Limb-length discrepancy
4- Cavitary acetabular bone loss
5- Chronic instability
Figures
Answer (click for answer)
Answer-5- Chronic instability
The concept is that a bipolar or hemiarthroplasy have a large head to neck ratio. In the revision of an unstable total hip from soft tissue laxity, hemiartroplasty is a choice. Another choice could be to advance the abductors, or use a constrained liner It is not appropriate when the acetabulum has defects or discontinuity because it relies on a metal/cartilage articulation and can migrate into the pelvis. It is no better then a total hip in restoring leg length descrepency.
Reference: Miller MD: Review of Orthopaedics ed 3. Philadelphia PA,WB Saunders, 2000, pps245-246.