Axial and Sagittal Rotation of Cementless Tibial Baseplates Occurs in Bone Under Joint Loading

Matthew G Teeter; Jordan S Broberg; James L Howard; Brent A Lanting

doi:10.1016/j.arth.2023.03.002

Axial and Sagittal Rotation of Cementless Tibial Baseplates Occurs in Bone Under Joint Loading

J Arthroplasty. 2023 Jun;38(6):1166-1171. doi: 10.1016/j.arth.2023.03.002. Epub 2023 Mar 7.

Authors

Matthew G Teeter¹, Jordan S Broberg², James L Howard³, Brent A Lanting³

Affiliations

¹ Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Department of Surgery, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Imaging Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
² Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Imaging Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
³ Department of Surgery, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.

PMID: 36893992
DOI: 10.1016/j.arth.2023.03.002

Abstract

Background: There has been a recent increase in the use of cementless fixation for primary total knee arthroplasty. While the early results of contemporary cementless implants are promising, understanding the behavior of cementless tibial baseplates under loading remains an ongoing interest. The objective of this study was to identify the pattern of displacement that occurred under loading for a single cementless tibial baseplate design at one year post operation for stable and continuously migrating implants.

Methods: There were 28 subjects from a previous trial of a pegged highly porous cementless tibial baseplate evaluated. Subjects underwent supine radiostereometric exams from two weeks through one year after surgery. At one year, subjects also underwent a standing radiostereometric exam. Fictive points on the tibial baseplate model were used to relate translations to anatomical locations. Migration over time was calculated to determine if subjects displayed stable or continuous migration. The magnitude of inducible displacement between the supine and standing exams was calculated.

Results: Inducible displacement patterns were similar between stable and continuously migrating tibial baseplates. Displacements were greatest in the anterior-posterior axis followed by the lateral-medial axis. Correlation of displacements between adjacent fictive points in these axes indicated an axial rotation of the baseplate occurred under loading (r² = 0.689-0.977, P < .001). Less displacement occurred in the superior-inferior axis and correlations indicated an anterior-posterior tilt of the baseplate occurred under loading (r² = 0.178-0.226, P = .009-.023).

Discussion: From supine to standing position the predominant pattern of displacement for this cementless tibial baseplate was axial rotation, with some subjects also displaying an anterior-posterior tilt.

Keywords: cementless fixation; inducible displacement; radiostereometric analysis; tibial baseplate; total knee arthroplasty.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arthroplasty, Replacement, Knee* / methods
Humans
Knee Joint / surgery
Knee Prosthesis*
Prosthesis Design
Rotation
Tibia / surgery

Grants and funding

CIHR/Canada