TOPLINE:

In knees of adults without radiographic osteoarthritis (OA), MRI-detected structural changes were prevalent over 6 years, with more than 75% developing cartilage damage. Risks were more profound in the patellofemoral joint than in the lateral tibiofemoral joint, and only 4% of the knees reached radiographic tibiofemoral OA.

METHODOLOGY:

• Researchers conducted a prospective cohort study to examine changes in the structural features in knees of individuals without radiographic OA at baseline (Kellgren-Lawrence grade 0).
• They analysed MRI scans of 680 knee joints from 340 individuals (mean age, 51 years; 51% women) included from the OA Initiative study. OA risk status was assigned at the knee level on the basis of factors such as injury, surgery, symptoms, BMI, knee bending, and family history, comparing changes between "at-risk" (n = 430) and "not-at-risk" (n = 250) knees.
• MRI scans were conducted at baseline and 24, 48, and 72 months, with changes defined as at least a 1-grade increase in any subregion.
• MRI features were evaluated using the MRI Osteoarthritis Knee Score system, focusing on cartilage damage, osteophytes, bone marrow lesions, and meniscal damage.
• Changes were assessed in the medial tibiofemoral, lateral tibiofemoral, and patellofemoral compartments, along with changes in the meniscus.

TAKEAWAY:

• Cartilage damage was noted in 76% of knees and meniscal damage was noted in 18% of knees over 6 years; only 4% progressed to radiographic tibiofemoral OA (Kellgren-Lawrence grade ≥ 2).
• Structural changes were most frequently seen in the patellofemoral joint, with higher risks observed for cartilage damage (adjusted risk ratio [aRR], 1.6; 95% CI, 1.3-2.1) and bone marrow lesions (aRR, 1.8; 95% CI, 1.5-2.2) than for those in the lateral tibiofemoral joint.
• The risk for meniscal damage was higher in the medial tibiofemoral compartment than in the lateral tibiofemoral compartment (aRR, 2.0; 95% CI, 1.4-3.0).
• Knees at risk were associated with a higher risk of developing meniscal damage than knees not at risk (aRR, 1.6; 95% CI, 1.1-2.3), but no associations were noted for changes in other MRI features.

IN PRACTICE:

"Research in this area may help identify targets for early OA treatment and prevention of progression, with our findings suggesting that MRI-detected structural changes could support risk stratification, earlier monitoring, and timely intervention before radiographic OA develops," the authors wrote.

SOURCE:

This study was led by Karin Magnusson, PhD, Lund University, Lund, Sweden. It was published online on December 06, 2025, in Osteoarthritis and Cartilage.

LIMITATIONS:

The study's generalisability was limited due to the specific inclusion criteria and the need for participants to attend multiple follow-up visits. The weak correlation between symptoms and structural changes may also have affected the interpretation of the results.

DISCLOSURES:

This study was supported by grants from the Swedish Research Council, the Swedish Rheumatism Association, the Österlund Foundation, and other foundations. One author reported being a past consultant for Grünenthal Sweden AB and Key2Compliance AB, and another author reported serving as an associate editor for statistics in Osteoarthritis and Cartilage.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.