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we had started to question the reality of these
situations in the evaluation of preoperative
stress X-rays.
In addition, how can we analyze the intra- and
extra-articular deformities in the preoperative
evaluation by stress radiographs and also, are
these data’s useful in the planning of soft tis-
sue release procedures in TKA surgery? In this
study, we used a.TFs and compartment space
width measurement techniques to detect the
intra-articular changes by the application of
varus/valgus forces to the knee. Previous stu-
dies have extensively used these measurement
techniques as a global methodology [18, 20,
26, 27] which are influenced by the cartilage
and bone loss in the compartments of the joint
and by the tension of the collateral ligaments
and marginal osteophytes. In present study, we
found that the femorotibial separation angle
and the medial/lateral joint space widths were
differed from the normal knee but the compa-
risons between the surgical groups by stress
radiographs did not give any foresight for
planning soft tissue release procedure in TKA
(p>0.05).
However, the third measurement method;
femorotibial anatomical angle which is
influenced by intra- and extra-articular defor-
mities on varus and valgus stress X-rays sho-
wed significant difference between the groups.
The value of FTA, less than 175.8° on valgus
stress addressed us that the unreduced defor-
mity needed to be corrected by intra-articular
bone resection and an excessive release proce-
dure in the medial side with lengthening the
superficial MCL to the pes anserinus insertion.
In addition, the FTA 179.5° showed that the
deformity was reducible and performing the
medial release was unnecessary for the case.
These thresholds of FTA might allow warning
to plan the medial release in primary TKA.
However, the question still remained in
making a decision to perform pie-crusting
technique depending on the surgeons expe-
rience (no statistically significant difference
was found between group 1 and 2, p=1).
In clinical practice, the varus and valgus stress
X-rays using FTA give objective information
about the reducibility of the deformity and soft-
tissue envelope in the preoperative evaluation
of TKA. However, most intra-operative assess-
ments of balance during TKA are performed
manually after the bone resections and are not
quantitatively assessed. The other possibilities,
in order to obtain objective and quantitative
information about the soft tissue envelope in
TKA surgery, can be the stress long-leg radio-
graphs pre-operatively, computer assisted sur-
gery, surgical tools and current force-sensing
devices intra-operatively [3, 5, 28, 32, 33].
CONCLUSION
A standardized varus and valgus stress X-rays
provide reliable information with FTA that
will help surgeons in the preoperative planning
for soft-tissue release procedures during TKA
in order to achieve proper ligament-balanced
knees with excellent long-term outcomes.
Therefore, the technique may be useful to plan
a soft tissue release to be adopted by the other
centers that are using conventional technique
without navigation in performing TKA.
ACKNOWLEDGEMENTS
The authors would like to thank Hatice Uluer,
MS, Department of Biostatistics, Ege
University Hospital, Izmir, for help with the
statistical analysis.
ARE STRESS X-RAYS USEFUL TO PLANMEDIAL SOFT TISSUE RELEASE PROCEDURES IN TOTAL KNEE ARTHROPLASTY?
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