Low-Contact-Stress Knee Arthroplasty: Past History or Ahead of Time?

Abstract

Low-contact-stress mobile-bearing (MB) total knee arthroplasty (TKA) can rely on a long history. Its concept comprises a combination of high condylar congruency and compensatory bearing rotation to promote load sharing. However, other MB designs have become available, and critical points have been raised about the benefit of MB in general. Although there is kinematic and kinetic support for the low-contact-stress concept, there is no tribologic or clinical proof of its superiority over fixed-bearing concepts. Further study should be controlled for differences in polyethylene quality and need to provide a measure of condylar congruency to differentiate authentic low-contact-stress variants form others. [Orthopedics. 2016; 39(3):e402-e412.].

Efficacy of a Second-Generation Rotating Bearing Tibial Platform in Total Knee Arthroplasty: A Prospective Observational Cohort Study with Registry Analysis

“…8 Since its inception, the original design of the low contact stress (LCS), total knee prosthesis has undergone modifications to improve usability and longevity. 9 Separation of the rotating bearing from the tibial cone was an early complication of the design, 10 with poor seating on the tibia and the appearance of radiolucency about the tibial plateau, particularly in uncemented procedures, associated with pain in individuals who had received a LCS prosthesis. 11 These findings may be associated with the stress concentration at the end of the tibial cone, 9 combined with a full porous coating which encouraged bone growth distally and resorption proximally, depending on placement.…”

“…9 Separation of the rotating bearing from the tibial cone was an early complication of the design, 10 with poor seating on the tibia and the appearance of radiolucency about the tibial plateau, particularly in uncemented procedures, associated with pain in individuals who had received a LCS prosthesis. 11 These findings may be associated with the stress concentration at the end of the tibial cone, 9 combined with a full porous coating which encouraged bone growth distally and resorption proximally, depending on placement. 12 To address some of these concerns, derivatives to the mobile-bearing LCS knee prosthesis were introduced, such as the rotating bearing knee (RBK; Global Orthopaedic Technology, NSW, Australia), with porous coating limited to the proximal third of the tibial cone and the introduction of additional tibial pegs for stability.…”