224 / 324
to correct execution of cuts. Two other parame-
ters we apply for sizing the resection are patel-
lar tendon length and patella height. The inex-
tensibility of the patellar tendon is an essential
parameter for correctly sizing the femoral
resection in order to obtain ideal patellar
height. A reduction in the Insall-Salvati ratio is
associated with a reduction in knee joint func-
tion and in the ability to climb stairs [21, 22].
When we perform tibial resections, we do not
alter the flexion or extension spaces, but we
can influence on the patellar height only per-
forming a small resection which would force
us to implant a smaller femoral size.
In conclusion, we believe that in order to cor-
rectly perform bone cuts, it is necessary to
consider several parameters, especially as
concerns the femur. We start from the concept
of maintaining the articular rim, and for this
purpose we perform a very conservative femo-
ral resection after evaluating the volumetrics
of the articular flexion and extension spaces
(posterior condylar offset): essential condi-
tions for obtaining good functional outcome
according to biomechanical studies. To do this,
prosthesis design with an ample range of
femoral components of different size gap
(2mm) is needed.
BONE CUTS FROM THE JOINT-LINE
223
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