Revision TKR: Revision of Tibial Component:

- Discusssion:
    - remove 1-2mm of bone using the intramedullary guide.
    - be aware of the preoperative flexion stability and ROM in choosing posterior slope;
    - for example, if the knee was unstable in flexion preoperatively, 0 degrees posterior slope may help reduce some of the flexion gap;
    - reaming for medullary stems:
           - after reaming to 12 mm, continue to procede slowly by 1 mm increments;
           - reaming should cease once firm resistance is encountered;
           - it is not necessary to have direct cortical contact, inorder to avoid excessive bone loss;
           - generally, stem diameter will be the same size as the reaming diameter;
    - debridement of remaining membrane debris:
           - all reactive membranes need to be removed;
    - insertion of trial tibial component:
           - place an appropriately sized tibial component and stem;
           - keep this component in position during femoral preparation;
           - typically it will be necessary to insert intra-medullary stems;
           - it is essential that the intra-medullary stem be inserted centrally in the medullary canal, which may or may not conform to the
                   center of the cut tibial surface;
           - if there is a descrepancy between central medullary rod position and an optimally positioned tibial joint surface, the difference is
                   made up w/ tibial wedges;
                   - the tibial surface may have to be recut to conform to the wedges;
           - tibial rotational alignment
                   - unlike a primary TKR, the trial tibial component usually cannot "find its optimal alignment" in relation to the femoral
                             component because the tibial stem locks the component in fixed rotation;
                   - consider alignment based on the center of the femoral component trochlea and tibial tubercle

- References:
       - Tibial Stems in Revision Total Knee Arthroplasty: Is There an Anatomic Conflict?



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, November 9, 2015 7:41 am