Quantifying the Human Subchondral Trabecular Bone Microstructure in Osteoarthritis with Clinical CT

Abstract

Osteoarthritis (OA) is characterized by critical alterations of the subchondral bone microstructure, besides the well‐known cartilaginous changes. Clinical computed tomography (CT) detection of quantitative 3D microstructural subchondral bone parameters is applied to monitor changes of subchondral bone structure in different stages of human OA and is compared with micro‐CT, the gold standard. Determination by clinical CT (287 µm resolution) of key microstructural parameters in tibial plateaus with mild‐to‐moderate and severe OA reveals strong correlations to micro‐CT (35 µm), high inter‐ and intraobserver reliability, and small relative differences. In vivo, normal, mild‐to‐moderate, and severe OA are compared with clinical CT (331 µm). All approaches detect characteristic expanded trabecular structure in severe OA and fundamental microstructural correlations with clinical OA stage. Multivariate analyses at various in vivo and ex vivo imaging resolutions always reliably separate mild‐to‐moderate from severe OA (except mild‐to‐moderate OA from normal), revealing a striking similarity between 287 µm clinical and 35 µm micro‐CT. Thus, accurate structural measurements using clinical CT with a resolution near the trabecular dimensions are possible. Clinical CT offers an opportunity to quantitatively monitor subchondral bone microstructure in clinical and experimental settings as an advanced tool of investigating OA and other diseases affecting bone architecture.

Comparison of clinical‐CT segmentation techniques for measuring subchondral bone cyst volume in glenohumeral osteoarthritis

“…First, the sample size was small, and no definite conclusions are possible based on these findings. However, this sample size is consistent with contemporary studies using micro-CT to look at bone [ 11 ], including those using Bland–Altman analysis [ 3 ]. An acceptable level of error for cyst volume measurements has not been clinically established, as the effects of subchondral bone cysts on clinical outcomes of glenohumeral OA are still being investigated.…”

Locally Directed Recombinant Adeno- Associated Virus–Mediated IGF-1 Gene Therapy Enhances Osteochondral Repair and Counteracts Early Osteoarthritis In Vivo

“…Multivariate analyses were performed for all available bone and cartilage parameters of the samples as described previously. 29 Principal component analysis (PCA) with a correlation matrix routine and nonparametric 1-way analysis of similarities (ANOSIM) with Gower similarity index were used. Considering multiplicity issues, we reported the Bonferroni-corrected P values.…”

A Photopolymerizable Biocompatible Hyaluronic Acid Hydrogel Promotes Early Articular Cartilage Repair in a Minipig Model In Vivo

“…Similar VOIs of the normal osteochondral unit were also examined in each trochlea, adjacent to the defects but not overlapping with them. The following quantitative 3D subchondral bone parameters were evaluated within each of the four volumes of interests (VOIs): [31,54] bone volume fraction (BV/TV), specific bone surface (BS/BV), bone surface density (BS/TV), and total porosity [Po (tot)]. Trabecular pattern factor (Tb.Pf), thickness (Tb.Th), separation (Tb.Sp), and number (Tb.N), structure model index (SMI), fractal dimension (FD), and degree of anisotropy (DA) were only determined in the subarticular spongiosa.…”

“…Multivariate analyses were performed for all available bone or cartilage parameters of the samples as described previously. [52][53][54]56] Principal components analysis (PCA) with a correlation matrix routine, and non-parametric one-way analysis of similarities (ANOSIM) with Gower similarity index were used, and considering multiplicity issues, the Bonferroni-corrected p-values were reported. [57] Calculations were performed using GraphPad Prism 7.03 (GraphPad Software, San Diego, CA, USA) or Past v. 4.04.…”