Does tibial design modification improve implant stability for total knee arthroplasty? An experimental cadaver study

Abstract

Aims One of the main causes of tibial revision surgery for total knee arthroplasty is aseptic loosening. Therefore, stable fixation between the tibial component and the cement, and between the tibial component and the bone, is essential. A factor that could influence the implant stability is the implant design, with its different variations. In an existing implant system, the tibial component was modified by adding cement pockets. The aim of this experimental in vitro study was to investigate whether additional cement pockets on the underside of the tibial component could improve implant stability. The relative motion between implant and bone, the maximum pull-out force, the tibial cement mantle, and a possible path from the bone marrow to the metal-cement interface were determined. Methods A tibial component with (group S: Attune S+) and without (group A: Attune) additional cement pockets was implanted in 15 fresh-frozen human leg pairs. The relative motion was determined under dynamic loading (extension-flexion 20° to 50°, load-level 1,200 to 2,100 N) with subsequent determination of the maximum pull-out force. In addition, the cement mantle was analyzed radiologically for possible defects, the tibia base cement adhesion, and preoperative bone mineral density (BMD). Results The BMD showed no statistically significant difference between both groups. Group A showed for all load levels significantly higher maximum relative motion compared to group S for 20° and 50° flexion. Group S improved the maximum failure load significantly compared to group A without additional cement pockets. Group S showed a significantly increased cement adhesion compared to group A. The cement penetration and cement mantle defect analysis showed no significant differences between both groups. Conclusion From a biomechanical point of view, the additional cement pockets of the component have improved the fixation performance of the implant. Cite this article: Bone Joint Res 2022;11(4):229–238.

High rate of radiolucent lines following the cemented original design of the ATTUNE total knee arthroplasty

“…22 In 2017, DePuy launched a modified tibial component (attUne s+) incorporating backside grooves with the aim of facilitating interdigitation of the cement to improve fixation. 57 However, an estimated 600,000 tKas were implanted before this change of design. 7 Furthermore, the rest the design remained the same and there is currently little clinical evidence that these changes have influenced the rates of RLL formation.…”

Consequences of using poly-ether-ether-ketone versus traditional implant on tibial cement penetration and short-term clinical outcomes during total knee arthroplasty: a randomized controlled trial

“…Previous studies have identified prosthetic debonding as a concern, as some tibial implants have ineffective strand locks at the prosthesis-bone cement interface, resulting in postoperative implant failure [ 25 – 27 ]. In an effort to address this issue, Jaeger et al [ 28 ] conducted a cadaver study, implanting a tibial component with and without additional cement pockets in 15 fresh-frozen human leg pairs. The authors found that the additional cement pockets were biomechanically advantageous, improving the fixation performance of the implant.…”

Is TKA femoral implant stability improved by pressure applied cement? a comparison of 2 cementing techniques

“…Afterwards, the specimens were cast in a mold using synthetic resin (Rencast FC 53, Huntsman Advanced Materials GmbH, Germany), in order to secure the specimens into the material testing machine. For the assessment of implant stability, an incremental dynamic load was applied at 1 Hz for the axial force with simultaneous extension-flexion between 20° and 50°, as had been done in a prior study [ 28 ]. The load maxima occurred at the time of extension and flexion, respectively [ 29 ].…”