Is the atrophic phenotype of tibiofemoral osteoarthritis associated with faster progression of disease? The MOST study

Abstract

Objective To assess the associations of atrophic tibiofemoral osteoarthritis (OA) with progression of radiographic joint space narrowing (JSN) and magnetic resonance imaging (MRI)-defined progression of cartilage damage. Design Participants of the Multicenter Osteoarthritis (MOST) Study with available radiographic and MRI assessments at baseline and 30 months were included. The atrophic OA phenotype was defined as OARSI grades 1 or 2 for JSN and grade 0 for osteophytes. Based on MRI, atrophic OA was defined as tibiofemoral cartilage damage grades ≥ 3 in at least 2 of 10 subregions with absent or tiny osteophytes in all tibiofemoral subregions. Progression of JSN and cartilage loss on MRI, was defined as 1) no, 2) slow, and 3) fast progression. Co-variance and logistic regression with generalized estimated equations were performed to assess the association of atrophic knee OA with any progression, compared to non-atrophic OA knees. Results A total of 476 knees from 432 participants were included. There were 50 (10.5%) knees with atrophic OA using the radiographic definition, and 16 (3.4%) knees with atrophic OA using MRI definition. Non-atrophic OA knees more commonly exhibited fast progression of JSN and cartilage damage. Logistic regression showed that the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss. Conclusion In this sample, the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss compared to the non-atrophic knee OA phenotype.

A 24-Month Follow-Up Study of the Effect of Intra-Articular Injection of Autologous Microfragmented Fat Tissue on Proteoglycan Synthesis in Patients with Knee Osteoarthritis

“…In clinical practice and clinical trials, radiography remains the primary imaging modality for the evaluation of OA, however, limitations of radiography for the visualization of OA features, including insensitivity to early changes, non-specificity, absence of reproducibility in longitudinal studies and challenges regarding positioning, significantly limits the utility of radiography both clinically and in the research field. OA is a disease process involving multiple joint tissues including those not visible on radiography [1], and is a complex disease process with multiple phenotypes [2,3] that require evaluation by multimodality imaging assessment. Therefore, the use of more advanced imaging modalities such as magnetic resonance imaging (MRI) has become important in OA research [1,4].…”

MRI-based screening for structural definition of eligibility in clinical DMOAD trials: Rapid OsteoArthritis MRI Eligibility Score (ROAMES)

“…An atrophic OA phenotype has been described exhibiting no or only tiny osteophytes yet marked cartilage loss 20 . A recent study based within the MOST cohort surprisingly showed that the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss compared to the non-atrophic knee OA phenotype 21 . Additional work will have to show the relevance of these two specific phenotypes in light of DMOAD trial inclusion.…”

“…These may progress differently and may represent distinct tissue targets for DMOAD approaches 6,19 . In addition, an atrophic (extended cartilage loss with small osteophytes) and hypertrophic phenotype (large osteophytes with minor cartilage damage) have been described with both being rare 20,21 . However, it should also be noted that more than one pathogenetic mechanism may be involved in the same patient to varying degrees during different phases of the disease and that one phenotype seldom exists in isolation.…”

The role of radiography and MRI for eligibility assessment in DMOAD trials of knee OA

“…Currently, there is no radiography-based definition of atrophic OA, with this entity usually being understood as a phenotype of OA exhibiting compartments or joints with definite joint space narrowing without any osteophytes or as a marked discordance between JSN and size of associated osteophyte formation. A recent study based within the MOST cohort surprisingly showed that the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss compared to the non-atrophic knee OA phenotype 57 .…”