Abstract
The lateral view of the hip joint after total hip replacement of 100 joints in 76 cases was studied. More than 5 years had passed since Weber-Stumer-type THR was carried out on them. We did follow-up examinations on their lateral view at 1-, 3-, and 6-months, 1-year, and after that yearly intervals. The lateral view was taken from inside to outside of the diseased joint which was arranged at neutral rotation, while the healthy knee and hip joint was arranged at a 90°flexion. We examined the conformity of the medullary cavity and stem, position of stem insertion, cementing state, bone reaction and clear zone appearance on the stem side. For the examination of the cementing condition, bone reaction and clear zone appearance, lateral views were classified into 7 zones, a, b, c, d, e, f and g.
With respect to the conformity of medullary cavity and stem, and position of stem insertion, the group which had a clear zone beyond stage 3 was not significant. In many cases, the cementing condition was poor at zones a, d and g. Any cementing state which was poor at more than one zone was classified as“poor”. In this group, the rate of the appearance of clear zones above stage 3 was significant. With respect to bone reaction, absorption at zone g and thinning at zone c were observed in many cases. It was shown that the clear zone often appears first in the lateral view. In the group above stage 3, it appeared 3 months earlier than in the A→P view. Thus the lateral view examination was proved to be important. It sometimes gave information earlier than the A→P view, and was useful especially for early diagnosis of loosening.
