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Preoperative Planning. What I do Before a UKA
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Limb Alignment
Excessive axial deformity of the femoro-tibial
mechanical axis threatens survivorship of a
UKA, due to excessive demands on fixation or
due to premature polyethylene wear. Ideally,
alignment of the FT axis is corrected by the
prosthesis, restoring the original deformity of
that knee. This “native deformity” or alignment
normally corresponds with an under-correction
sought at the end of the procedure, as opposed
to the 180 degree reference which is, for many
surgeons, the target for TKR. The pre-operative
deformity, when measured by goniometry,
combines both the native malalignment plus
the intra-articular wear, but it remains the
measurement of choice by tradition (fig. 13).
Fig. 11: Lateral inter-condylar notch osteophyte
rubbing against the ACL.
Fig. 12: Re-evaluation of the ACL after notchplaty
showing a solid and functional aspect of the
ligament.
Fig. 13: Long legs film showing the
global deformity of the left knee.
Femoro-tibial angle is of 7° of varus.