Tibial cartilage, subchondral bone plate and trabecular bone microarchitecture in varus- and valgus-osteoarthritis versus controls

Sophie Rapagna, Bryant C. Roberts, Lucian B. Solomon, Karen J. Reynolds, Dominic Thewlis, Egon Perilli

Research output: Contribution to journalArticlepeer-review

Abstract

This preliminary study quantified tibia cartilage thickness (Cart.Th), subchondral bone plate thickness (SBPl.Th) and subchondral trabecular bone (STB) microarchitecture in subjects with varus- or valgus- malaligned knees diagnosed with end-stage knee osteoarthritis (OA) and compared them to controls (non-OA). Tibial plateaus from 25 subjects with knee-OA (undergoing knee arthroplasty) and 15 cadavers (controls) were micro-CT scanned (17 µm/voxel). Joint alignment was classified radiographically for OA subjects (varus-aligned n = 18, valgus-aligned n = 7). Cart.Th, SBPl.Th, STB bone volume fraction (BV/TV) and their medial-to-lateral ratios were analyzed in anteromedial, anterolateral, posteromedial and posterolateral subregions. Varus-OA and valgus-OA were compared to controls. Compared to controls (1.19–1.54 mm), Cart.Th in varus-OA was significantly lower anteromedially (0.58 mm, −59%) and higher laterally (2.19–2.47 mm, +60–63%); in valgus-OA, Cart.Th was significantly higher posteromedially (1.86 mm, +56%). Control medial-to-lateral Cart.Th ratios were around unity (0.8–1.1), in varus-OA significantly below (0.2–0.6) and in valgus-OA slightly above (1.0–1.3) controls. SBPl.Th and BV/TV were significantly higher medially in varus-OA (0.58-0.72 mm and 37–44%, respectively) and laterally in valgus-OA (0.60–0.61 mm and 32–37%), compared to controls (0.26–0.47 mm and 18–37%). In varus-OA, the medial-to-lateral SBPl.Th and BV/TV ratios were above unity (1.4–2.4) and controls (0.8–2.1); in valgus-OA they were closer to unity (0.8-1.1) and below controls. Varus- and valgus-OA tibia differ significantly from controls in Cart.Th, SBPl.Th and STB microarchitecture depending on joint alignment, suggesting structural changes in OA may reflect differences in medial-to-lateral load distribution upon the tibial plateau. Here we identified an inverse relationship between cartilage thickness and underlying subchondral bone, suggesting a whole-joint response in OA to daily stimuli.

Original languageEnglish
Number of pages12
JournalJournal of Orthopaedic Research
Early online date25 Nov 2020
DOIs
Publication statusE-pub ahead of print - 25 Nov 2020

Keywords

  • bone microarchitecture
  • cartilage
  • knee osteoarthritis
  • micro-CT
  • tibial plateau

Fingerprint Dive into the research topics of 'Tibial cartilage, subchondral bone plate and trabecular bone microarchitecture in varus- and valgus-osteoarthritis versus controls'. Together they form a unique fingerprint.

Cite this