MCQs-Hip Recon. 3
abduction/adduction. Remember that you cannot do a varus osteotomy if they lack abduction, and you cannot do a valgus osteotomy if they lack adduction. Then check to see at which position they have an increase in their joint space. If they have increased joint space on abduction and extension of the hip, you can reproduce this position by doing a varus osteotomy and a flexion osteotomy. If they have increased joint space on adduction, then consider a valgus osteotomy.
– if doing an uncemented stem and you find that it toggles – ream and insert a bigger stem! You often cannot back out of this and put a cemented stem in, because you’ve reamed all the cancellous bone away!
– for gram negative hip sepsis, do a two stage implantation, but probably wait a whole year before re-implanting.
– if you decrease the femoral offset, you increase the risk of dislocation. You shorten the lever arm for the abductors, so they have to work harder, and the joint reaction force is increased, and the energy required to walk is increased. The major problem is de-tensioning the soft tissue sleeve and thus increasing risk of dislocation.