Learning objectives
To discuss the most important radiological measurements of hip prosthesis.
Background
Total hip arthroplasty is the most successful method of treatment for patients with severe osteoarthritis,
femoral head avascular necrosis or proximal femur fractures.
Total hip arthroplasty systems are modular and allow better selection of components for every patient.
Malposition of prosthesis components results in impingement syndrome,
accelerated wear or unexplained pain.
The main role of imaging is to assess the position of the components and their relationship to surrounding structures.
Most radiological measurements can be assessed in standard pelvic x-ray.
It is nessesary to obtain...
Imaging findings OR Procedure Details
Pelvic tilt
Sagittal balance of pelvis can influence position of acetabular component (Fig.1,2).
In case of imbalance the compensatory mechanism can cause shift in pelvic tilt to anterior or posterior side and accelerated hip osteoarthritis.
With pelvic tilt posteriorly,
acetabular component anteversion may increase as the patient's position changes from standing to sitting.
Acetabular version angle
Acetabular version angle is the angle between coronal plane and edges of acetabular component.
Acetabular version angle can be:
Radiological- angle between the acetabular axis and the coronal plane...
Conclusion
Correct position of hip prosthesis components is necessary for a good long-term outcome and patient satisfaction.
A radiologist should be familiar with clinically significant radiological measurements.
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The association between Femoral Tilt...