186 C. N. PECK ET AL.
forming the hip replacements. However, no measure of
spread was provided in Leonard’s paper.
We acknowledge the limitations of the present study
which should be considered when in terpreting the results.
The surgeries were carried out by five different consult-
ants in lower limb reconstruction each with their own
variations on templating and intraoperative methods to
equalise leg lengths. No account was taken of the
pre-existing limb length which can have a direct impact
on the post operative limb length. Additionally, no as-
sessment was made of disease in the contralateral hip
which may also have a bearing on a surgeons desired
final leg length of the operated hip . Due to the retrospec-
tive nature of the study we were unable to compare the
size of the prosthesis used with the size of prosthesis
templated for. This would have given us a better under-
standing as to whether the size of final implants may
have changed leg length.
The general limitations of using radiographs to make
our measurements include the variation in positioning of
the pelvis with respect to the x-ray film and variations in
relative magnification due to distance from the film.
However, as these factors affect both hips and we are
comparing the difference between the two it is reason-
able to use plain radiographs to assess leg length. Our
methods of measuring leg length discrepancy have been
used in numerous other studies [5,8,11,12,15] and are
considered to be accurate and reliable. To calculate the
magnification the radiographic diameter of the prosthetic
femoral head can be compared to the actual diameter of
the prosthesis. This data was not available in the current
study so a standard magnification factor of 20% was
used to adjust the actual measurements taken from the
radiographs. However, this is the standard magnification
used in most templating systems and consistent with
other studies [3,10,14,15].
5. Conclusions
In conclusion, total hip arthroplasty is a safe, effective
and reproducible treatment for end stage degenerative
hip disease. The current trend is towards the use of ce-
mentless implants particularly in the younger patient.
Our study shows that there is no significant difference in
leg length discrepancy between cementless and cemented
implants. This suggests that with accurate pre-operative
templating both cemented and cementless procedures
produce comparable and acceptable leg length discrep-
ancies.
6. Conflict of Inter e st S ta t e me nt
No benefits in any form have been received or will be
received from a commercial party related directly or in-
directly to the subject of this article.
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