Smith & Nephew REDAPT - Page 9

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Standardized A-P radiographs are also critical
in assessing proper femoral oset. If there is a
native hip on the contralateral side, the proper
oset can be determined by the horizontal
distance between the center of rotation of the
head and anatomic axis of the femur. If there
is a well functioning total hip prosthesis on the
contralateral side, a similar assessment can be
made using the REDAPT™ templates.
Diculties sometimes arise when the
contralateral hip is deformed or has a
malfunctioning THA. Additional problems may
be encountered if the ipsilateral acetabulum
has failed or has a protrusio deformity. In these
cases, it is up to the surgeon to determine
intraoperatively what the proper oset should
be so as to achieve a hip that is stable without
impingement in all physiological positions.
Once the bone stock has been assessed
and proper leg length and oset have been
determined, the surgeon should template
the femur to determine the appropriate
stem size. If there is any compromise in the
diaphyseal femoral bone, it is recommended
that the implant bypass the decient bone by
approximately 5-7cm and that it engages in
good diaphsyeal bone.
REDAPT templates are available in digital and
acetate formats (Figure 3). Consult your Smith
& Nephew representative for assistance in
obtaining templates.
Surgeon tip After the preliminary femoral stem
size is determined, physically draw these on
the A-P radiograph in proper position. Drawing
is valuable when selecting the proper implant in
conjunction with the intraoperative ndings so
as to establish the proper implant position.
Figure 3