| BUECHEL-PAPPAST KNEE REPLACEMENT SYSTEM - REVISION |
Surgical
Concepts
The basic procedure given here is intended for the typical
revision case where there is substantial loss of bone. It
uses a minimum of instruments consistent with the ability
to insert a set of trials which, when stabilized with REBAR
screws, are used to determine the final position of the revision
components. For those cases where there is sufficient bone
stock to provide direct support for the trials, an auxiliary
set of instruments is provided.
The surgical
technique employed, where there is insufficient bone to support
compressive load transfer through the prosthesis-bone interface
directly, is the use of a screw supported bone graft or cement
augment. For example, for cemented fixation if there is insufficient
proximal tibial bone stock, screws are implanted in the available
bone such that their heads will support the tibial component
at a position maintaining the joint line. The tibial trial
can be placed on screw heads, its position and stability assessed
and the screw head level adjusted until the tibial component
is correctly positioned and stable. When the implantable tibial
component is cemented in place the cement is used to fill
any defects. In this construct the screws act as cement reinforcing
elements helping the cement resist shearing and tensile loads.
Alternately, for cementless technique, screws can be used
to fixture the bone graft replacing lost bone stock. A similar
technique can be used for reconstruction of deficient distal
femoral bone.
This
technique avoids the need for metallic augments, or the need
for a variety of metallic components with a series of different
fixation geometries which substantially increase cost. Further,
augments can be a source of metal to metal rubbing which will
generate toxic wear debris.
The minimal additional instrumentation associated with the
implantation of the B - P revision components decreases the
cost and increases the convenience of utilizing these components.
This simplicity of instrumentation thus reduces cost and complexity
of revision and salvage surgery, a situation where such reduction
is badly needed.
Revision
Knee Surgical Procedure
Basic Steps
Auxiliary
Steps
Revision
Knee Instruments and Trials
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