PMC2729255_01
Radiographs show irregularity of the surface of the left acetabulum and osteoporotic changes of the superior part of the left acetabulum in comparison with the right hip. There is an obvious pseudoarthrosis of the femoral neck after internal fixation.
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fig1
Radiographs obtained at that time showed pseudoarthrosis of a left femoral neck fracture (Figure 1).
The outer head is set adequately in the acetabulum.
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fig2
We did not recognize supra-acetabular instability during surgery (Figure 2).
Subluxation of the outer head is apparent. The superior part of the acetabulum shows compression and the inclination of acetabular subchondral bone is increased compared with that on the right side.
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fig3
An antero-posterior radiograph obtained at that time showed slight subluxation of the outer head of the prosthesis and a compression fracture of the superior part of the acetabulum (Figure 3).
The outer head is dislocated completely. The outer part of the subchondral bone is inclined in the superior direction.
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fig4
Collapse at the fracture site progressed over time and the outer head dislocated completely at 6 weeks after surgery (Figure 4).
There is no loosening of the acetabular component at three years after revision surgery.
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fig5
There was no sign of infection and the stability of this new acetabular component was very good (Figure 5).