Master Techniques in Orthopedic Surgery Knee CH21

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PART IV Revision Total Knee Arthroplasty

FIGURE 21-13. The 3D printed titanium femoral cones are bilobed in design to ensure they bottom out, preventing longitudinal fractures of the femur.

FIGURE 21-14. A central symmetric femoral reamer is inserted to a specific depth that corresponds to the size of the three-dimensional printed titanium cone.

Restoration of Flexion and Extension Gaps Prosthesis sizing and positioning is used to recreate balanced flexion and extension gaps. At this stage, appropriate component rotation and alignment must be set; and component sizes, stem extensions, and conventional modular augments are selected and assembled. In most cases where metaphyseal cones are used, standard metal block augments are also required to address distal or posterior femoral bone loss, especially if isolated to one condyle.

FIGURE 21-15. An intramedullary device is placed in the femur at the corresponding depth, and in the appropriate amount of external rotation, to prepare for the smaller side reamers.

FIGURE 21-16. The smaller side reamers are used to mill out the bone for the bilobe design of the femoral cone.