J Knee Surg 2021; 34(02): 192-199
DOI: 10.1055/s-0039-1694055
Original Article

Primary Stability in Cementless Rotating Platform Total Knee Arthroplasty

1   Department of Orthopaedic Biomedical Engineering, Joint Replacement Surgeons of Indiana Research Foundation, Mooresville, Indiana
,
Renee D. Rogge
2   Department of Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana
,
Eric M. Reyes
3   Department of Mathematics, Rose-Hulman Institute of Technology, Terre Haute, Indiana
,
Ryan B. Seale
2   Department of Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana
,
Jeffrey B. Elliott
2   Department of Biology and Biomedical Engineering, Rose-Hulman Institute of Technology, Terre Haute, Indiana
,
Robert A. Malinzak
1   Department of Orthopaedic Biomedical Engineering, Joint Replacement Surgeons of Indiana Research Foundation, Mooresville, Indiana
› Author Affiliations
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Abstract

Highly porous ingrowth surfaces have been introduced into tibial tray fixation to improve long-term survivorship in cementless total knee arthroplasty. This study was designed to evaluate the effect of porous ingrowth surface on primary stability in the implanted cementless tibial component. Three tibial tray designs possessing sintered bead or roughened porous coating ingrowth surfaces were implanted into a foam tibia model with primary stability assessed via digital image correlation during stair descent and condylar liftoff loading. Follow-up testing was conducted by implanting matched-pair cadaveric tibias with otherwise identical trays with two iterations of ingrowth surface design. Trays were loaded and micromotion evaluated in a condylar liftoff model. The sintered bead tibial tray exhibited slightly lower micromotion than the roughened porous coating in stair descent loading. However, no significant difference in primary stability was observed in condylar liftoff loading in either foam or cadaveric specimens. Cementless tibial trays featuring two different iterations of porous ingrowth surfaces demonstrated both good stability in cadaveric specimens with less than 80 microns of micromotion and 1 mm of subsidence under cyclic loading. While improved ingrowth surfaces may lead to improved biological fixation and long-term osteointegration, this study was unable to identify a difference in primary stability associated with subsequent ingrown surface design iteration.



Publication History

Received: 12 April 2019

Accepted: 28 June 2019

Article published online:
08 August 2019

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