In fifty-two patients with Muller total hip replacement,
roentgenographic measurements of prosthetic component positioning were
correlated with hip-muscle strength and mobility measurements. Compared
with the normal side, the average position of the center of the prosthetic
head was more medial and superior in the pelvis, and the greater trochanter
was more distal and lateral. Increasing neck length (distance from the
center of the prosthetic head to the lesser trochanter) and a more distal
position of the greater trochanter were among the measurements that related
favorably to measurements of patient function. More superior placement of
the center of the prosthetic head in the pelvis was associated with a more
superior position of the lesser trochanter, which related adversely to
function.