Several factors have been implicated in unsatisfactory
results after total hip replacement (THR). We examined whether femoral
offset, as measured on digitised post-operative radiographs, was
associated with pain after THR. The routine post-operative radiographs
of 362 patients (230 women and 132 men, mean age 70.0 years (35.2
to 90.5)) who received primary unilateral THRs of varying designs
were measured after calibration. The femoral offset was calculated
using the known dimensions of the implants to control for femoral
rotation. Femoral offset was categorised into three groups: normal
offset (within 5 mm of the height-adjusted femoral offset), low
offset and high offset. We determined the associations to the absolute
final score and the improvement in the mean Western Ontario and
McMaster Universities osteoarthritis index (WOMAC) pain subscale
scores at three, six, 12 and 24 months, adjusting for confounding
variables. The amount of femoral offset was associated with the mean WOMAC
pain subscale score at all points of follow-up, with the low-offset
group reporting less WOMAC pain than the normal or high-offset groups
(six months: 7.01 ( Cite this article: