154 / 242
D. Saragaglia, M. Blaysat, M. Grimaldi
154
to 83.3 ± 7.5 points and the mean KOOS score
was of 95.1 ± 3.2 points. These Clinical results
are remarkable and the satisfaction of the
patients is very high (95% of the patients
satisfied or very satisfied). At mid-term follow
up no patient was revised to TKR or to another
osteotomy. This issue could be related not only
to the accurate correction – good over correction
and no oblique joint line – but also to the
vascular effect of double osteotomy at each
side of the joint line.
When should double level osteotomy be
performed? If we consider the “normal”
mechanical axis of the lower limb as described
by Kapandji [10] and later taken up by
Hungerford and Krackow [6] it should be 180°
with an MDFMAof 93° and an MPTMAof 87°
resulting in a joint line perfectly parallel to the
ground. However this assumption is not
confirmed in case of osteoarthritis with varus
misalignement, because, in a personal
unpublished series of 89 TKR, we found an
MDFMA of 93° in only 43.8% of cases; It was
at 90° in 33.7% of the cases, below 90° in
13.5% and above 93° in 9%.
Thus, before performing high tibial osteotomy,
it is crucial to have high quality and reproducible
full-length AP radiographs of the lower limb,
according to a specific protocol [23]. The HKA
angle, the MDFMA and the MPTMA should be
determined on this goniometry (fig. 2). Lateral
instability testing has become less important
than it once was, since the indications for
osteotomy in this setting have become rare. In
case of femoral valgus (MDFMA > 90°-91°), it
is illogical to perform a femoral osteotomy
because we do not want to create in the femur,
the error, we are trying to avoid in the tibia. If
the femur is in varus or at 90°, we think that,
we should proceed with a femoral osteotomy to
achieve an MDFMA of around 93° (93° ± 2°),
and then complete it with a tibial osteotomy to
achieve an HKA angle of 182° ± 2°. In our
experience, it is useless to overcorrect more
than this, to obtain satisfactory results (fig. 3, 4).
Overcorrection, whether femoral or tibial, can
distort the anatomy and lead to a much more
complicated revision TKR. Our mid-term
results have trend to confirm this assertion.
However, we think that a longer follow-up is
needed to prove that overcorrection by ± 2° is
enough for a lasting good result. If the tibia is
not in varus (MPTMA over 88°), we should
perform a femoral osteotomy especially if the
femur is at 90° or in varus or contraindicate any
osteotomy if it leads to joint line obliquity of
more than 5°. If we stick strictly to these
criteria, indications for double level osteotomy
will likely increase with the development of
navigation systems, especially since, as we said
before, femurs in varus are not rare, and more
so, those at 90°.
Finally, despite our trust in opening wedge
osteotomies [24], we think that, at the femoral
level, one should perform a closing wedge
osteotomy to avoid excessive lengthening of
the limb (double opening).
Fig. 3: DLO of the case of figure 2: notice that the
joint line is horizontal.