Extract
Numerous publications clearly support the conclusion that, overall, total
knee arthroplasty is successful. The definitive improvement in quality of
life, in combination with the aging of the population, has led to an
increasing demand for total knee arthroplasty. While cruciate-retaining and
posterior-stabilized devices will perform well for the vast majority of
patients presenting as candidates for primary total knee arthroplasty, the
orthopaedic surgeon occasionally encounters cases of advanced severity
(Figs. 1-A and
1-B)1-4.
Complex presentations range from higher degrees of ligamentous incompetency to
severe restriction of the range of motion with substantial flexion contracture
to posttraumatic arthritis and to post-osteotomy deformity of either the
distal part of the femur or the proximal part of the tibia. The challenge
confronting the reconstructive surgeon is to obtain a well-balanced
flexion-extension gap with balanced collateral ligaments. This is frequently
best accomplished with a modular system that offers a continuum of constraint
(Fig. 2). Modularity allows
intraoperative customization; namely, the use of stems, wedges, and augments.
Frequently these difficult primary arthroplasties require the use of
posterior-stabilized constrained
implants1,5-16.