Session V: Revision total knee replacement: an overview.

Revision total knee surgery has evolved through ened with time such that, at the time of revision the decade of the 1990s so that it has a pretotal knee replacement, equalization of the dictable outcome if certain principles are obextension and flexion gap or mediolateral staserved. These principles include the underbility is not possible or is so compromised that standing of the loss of biologic constraint of mechanical constraint is needed to augment the knee by ligamentous instability and musbiologic constraint. This usually means that a cle function and the consequent choice of meconstrained condylar knee design must be used. chanical implant constraint; the compromise Scuderi8 agrees with the current author that to the metaphyseal bone of the femur and tibia instability of knees at the time of revision toand the resultant necessity for the use of bone tal knee replacement provides the indication graft and stems; and the technical performance for a CCK prosthesis. Trousdale et al reported of the operation to optimize the function of the that 80% of 20 Total Condylar-III (forerunner extensor mechanism. of the CCK) knee replacements still were inSharkey and colleagues stated that instatact at 15 years. (Trousdale RT, Beckenbaugh bility was the predominant cause for failure JP, Pagnano MW: Why are knee replacements (Sharkey PF, Hozack WI, Rothman RH, Shasfailing today? Presented at the Annual Meettri S, Jacoby SM: 15 year results with Total ing of the American Academy of Orthopaedic Condylar III implants in revision total knee Surgeons, San Francisco, 2001.) This finding arthroplasty. Presented at the American Assoagrees with the experience of the current auciation of Hip and Knee Surgeons Meeting, thor that technically correct CCK design knee Dallas, TX, 2001). Instability can result from prostheses have excellent durability. inequality of the flexion and extension gaps Maximum mechanical constraint is a hinged from inadequate correction of sagittal plane dedesigned knee prosthesis and the common indiformities, or the medial compartment-lateral cation for this is global instability of a knee, compartment balance after releases for correcwhich includes bone loss including the ligation of coronal plane angulations. Instability afmentous insertion (especially the medial collatter primary total knee replacement can be worseralligament), loss of the extensor mechanism in an unstable knee (including loss of muscle From The Arthritis Institute, Inglewood, CA. control), and a flexion gap so large that a CCK Reprint requests to Lawrence D. Dorr, MD, The Arthriprosthesis cannot provide adequate stability 1 tis Institute, 501 E. Hardy Street, 3rd Floor, Inglewood, S . 19 d d. al 1 .. CA 90301. Phone: 310-695-4800; Fax: 310-695-4802;Epnnger et a reporte Ism resu ts wIth