Posterior-Stabilized Constrained Total Knee Arthroplasty for Complex Primary Cases

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.