Can Normal Knee Kinematics Be Restored with Unicompartmental Knee Replacement?

Abstract

In this in vitro cadaver study, the tricompartmental replacement significantly changed knee kinematics while the unicompartmental replacement preserved normal knee kinematics.

Kinematics of passive flexion following balanced and overstuffed fixed bearing unicondylar knee arthroplasty

“…In contrast to our findings, a previous study on the kinematics of fixed bearing UKA (Preservation; DePuy, Johnson and Johnson, Warsaw, IN, USA) reported no differences in axial rotation of the tibia or femoral rollback compared to that of the native knee [8]. However, their loading device was more constrained, and did not appear to allow for axial rotation.…”

“…This allows the surgeon to assess the alignment of the limb through a range of motion, and to appraise the interaction between the passive structures including the native and replaced articular surfaces, and the soft tissue envelope [7]. It is known that UKA more closely replicated normal kinematics of the native knee as compared to TKA during a simulated closed kinetic chain knee extension similar to stair-climbing [8]. Furthermore, using a similar device kinematics following UKA resembled those of knees with a torn medial meniscus with less internal rotation of the tibia with flexion [9].…”

Does Bearing Design Influence Midterm Survivorship of Unicompartmental Arthroplasty?

“…Although TKA remains the gold standard, with survivorship figures of 92% to 100% [3,15,16,25,30], more recent reports demonstrate UKA survivorship of 84% to 98% over the mid-to long term [14,16,34,35,37,44,[54][55][56][57]59]. Proposed advantages of UKA over TKA include the comparative ease of revision [12,24,28,33,50] and patient preference for improved knee kinematics [1,18,22,40,42,43] and function [19,36], and with less blood loss [23] and shorter inpatient stay [46].…”

Effect of Polyethylene Crosslinking and Bearing Design on Wear of Unicompartmental Arthroplasty

“…Unicompartmental arthroplasty (UKA) preserves the rest of the joint and has been shown to better approximate normal knee kinematics than TKA [5]. However, survivorship after unicompartmental arthroplasty is often lower than that after TKA [6,7].…”