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to them, and moreover, this would almost per
definition require some degree of surgical
medial soft tissue release [14-15]. Restoring
the knee to its constitutional alignment by
leaving it in in slight varus and in harmony
with its surrounding soft issue sleeve could
therefore be a more logical option. Recently
published studies seem to confirm this [12-14].
Vanlommel et al noted that preoperative varus
knees that were corrected to their constitutional
alignment did perform better both functionally
as well as subjectively when compared to those
knees that were restored to neutral mechanical
alignment [12].
The debate continues however on which is the
most optimal method to restore constitutional
alignment. In theory several options exist. One
could leave the femoral and/or tibial component
slightly undercorrected, or one could aim for
full anatomic restoration, including the
obliquity of the joint line.
The latter has been popularized as kinematic
alignment reconstruction, during which the
eroded or damaged parts of the knee are
resurfaced to its original anatomic contours.
Today it remains however undetermined
whether one of these strategies is to be
considered superior in terms of functional and
Fig. 1: Histogram depicting the large variability in natural alignment
in healthy male individuals, which contradicts the general belief that
normal alignment is zero. In fact large variability exists between
individuals, and the average alignment in males is around 2° varus.
Fig. 2: Typical constitututional
varus knee with medial OA (left)
requiring knee arthroplasty. The
typical characteristics are clearly
shown; varus OA of the knee, varus
hip neck-shaft angle, varus femoral
bowing, and varus of the
unaffected leg.