Bipolar 型人工骨頭置換術後の outer head の移動に関する検討

抄録

Radiographic assessment was done to investigate outer head migration after bipolar arthroplasty in 44 osteoarthritic hips (35 patients). Bone graft was performed on the lateral edge of the acetabulum using resected femoral heads in 19 cases who had dysplastic acetabulae.
There was a significant correlation at six months between CE angle and medial migration (r=-0.43, p<0.05). This indicates that the outer head placed with a smaller CE angle tends to move more medially.
Reaming depth toward the acetabular fossa affected superior migration of the outer head. The mean superior migration of the outer head in the deeper reaming group (>6mm) is significantly greater than that in the shallower reaming group (<5mm).
Thickness of the grafted bone correlated strongly with superior migration at 12 months (r=0.93, coefficient for slope=0.85). This result shows that the grafted bone did not act as a brake on the superior migration of the outer head.