title: The role of constraint in contemporary modular knee designs.
abstract: The current success of total knee arthroplasty (TKA) as a solution for arthritic problems about the knee is reflected in the increasing number of these procedures. The 1992 annual hospital discharge summaries indicate approximately 160,000 TKAs were performed in the United States for both primary and revision indications. Clinical success of TKA is rooted in a refined appreciation of patient habitus, technical proficiency and implant design. The understanding of this integrated triad has evolved over the past two decades. The evolution of knee implant design reflects recognition of the principle that implant geometry, acting in concert with surrounding soft tissues, determines the joint stability, range of motion and implant/bone interface forces. Interchangeable plateau geometries associated with modular designs, represent a recent development which permit an optimization of these interactions for a specific patient pathology. This paper describes a comparative evaluation of the geometrical constraint offered by six primary modular knee systems and describes their clinical applicability.
authors.affiliation: Orthopaedic Research Laboratories, The Mt. Sinai Medical Center, Cleveland, OH.
authors.forename: P D
authors.initials: PD
authors.lastname: Postak
authors.forename: C S
authors.initials: CS
authors.lastname: Heim
authors.forename: A S
authors.initials: AS
authors.lastname: Greenwald