2023 Volume No 45 – pages 60-71
Title: Microstructural adaptations of the subchondral bone are related to the mechanical axis deviation in end stage varus OA knees |
Authors: W Colyn, F Azari, J Bellemans, GH van Lenthe, L Scheys |
Address: Orthopaedic Department, AZ Turnhout, Steenweg Op Merksplas 44, 2300 Turnhout, Belgium |
E-mail: william_colyn at hotmail.com |
Abstract: Recent studies highlighted the crucial contribution of subchondral bone to OA development. Yet, only limited
data have been reported on the relation between alteration to cartilage morphology, structural properties
of the subchondral bone plate (SBP) and underlying subchondral trabecular bone (STB). Furthermore, the
relationship between the morphometry of the cartilage and bone in the tibial plateau and the OA-induced
changes in the joint’s mechanical axis remains unexplored. Therefore, a visualisation and quantification of
cartilage and subchondral bone microstructure in the medial tibial plateau was performed. End stage knee-OA
patients with varus alignment and scheduled for total knee arthroplasty (TKA) underwent preoperative fulllength
radiography to measure the hip-knee-ankle angle (HKA) and the mechanical-axis deviation (MAD). 18
tibial plateaux were μ-CT scanned (20.1 μm/voxel). Cartilage thickness, SBP, and STB microarchitecture were
quantified in 10 volumes of interest (VOIs) in each medial tibial plateau. Significant differences (p < 0.001)
were found for cartilage thickness, SBP, and STB microarchitecture parameters among the VOIs. Closer
to the mechanical axis, cartilage thickness was consistently smaller, while SBP thickness and STB bone
volume fraction (BV/TV) were higher. Moreover, trabeculae were also more superior-inferiorly oriented,
i.e. perpendicular to the transverse plane of the tibial plateau. As cartilage and subchondral bone changes
reflect responses to local mechanical loading patterns in the joint, the results suggested that region-specific
subchondral bone adaptations were related to the degree of varus deformity. More specifically, subchondral
sclerosis appeared to be most pronounced closer to the mechanical axis of the knee. |
Keywords: Osteoarthritis, subchondral bone, tibial plateau, varus alignment, μCT. |
Publication date: February 20th 2023 |
Article download: Pages
60-71 (PDF file) |
