FROM MENISCAL DEGENERATION TO OSTEOARTHRITIS: TRACKING EARLY DISEASE PROGRESSION WITH MRI-BASED COMPOSITE SCORES: DATA FROM THE OSTEOARTHRITIS INITIATIVE

INTRODUCTION

Meniscal degeneration predisposes knees without radiographic OA to develop a future meniscal tear and an accelerated onset and progression of OA. Understanding the relationship between meniscal degeneration and OA-related biomarkers in knees without radiographic OA is essential for improving early detection, monitoring disease progression, and developing intervention strategies to prevent or slow the progression of this debilitating condition.

OBJECTIVE

To explore the relationship between meniscal degeneration (intrameniscal signal alteration without a tear) and future OA pathology measured by composite scores based on MRI: disease activity (BM lesion and effusion-synovitis volumes) and cumulative damage (articular cartilage damage).

METHODS

Our sample included 225 participants from the OAI with intact menisci (defined as normal or meniscal degeneration without tear) on MRI and no radiographic knee OA at baseline. There were 110 participants with normal menisci (77% Female, 55 [SD 7] average years of age) and 115 with meniscal degeneration (60% Female, 61 [SD 9] average years of age). We used longitudinal MRIs from an existing study to calculate disease activity and cumulative damage. Negative values represent milder disease activity or cumulative damage than the average of a reference sample, among whom 93% had moderate-severe radiographic knee osteoarthritis (KLG = 3 or 4), and the average WOMAC knee pain score was 5.0 (SD=3.6). MR images were collected at each OAI site using Siemens 3.0 Tesla Trio MR systems and knee coils. Acquisitions included a sagittal IM fat-suppressed sequence (field of view=160mm, slice thickness=3mm, skip=0mm, flip angle=180 degrees, echo time=30ms, recovery time=3200ms, 313 × 448 matrix, x-resolution=0.357mm, y-resolution=0.357mm), which was used to measure BML and effusion-synovitis volumes. Cartilage damage was quantified using a 3D DESS sequence: field of view=140mm, slice thickness=0.7mm, skip=0mm, flip angle=25 degrees, echo time=4.7ms, recovery time=16.3ms, 307 × 384 matrix, x-resolution=0.365mm, y-resolution=0.365mm. We used robust regression models with M estimation and Huber weights to assess the association between baseline meniscal degeneration (exposure) and disease activity or cumulative damage at baseline and four annual follow-up visits (outcomes), adjusting for gender, race, age, static alignment, and body mass index.

RESULTS

Knees with meniscal degeneration were more likely to have, on average, 0.21 greater disease activity at 12 months than knees with normal menisci (parameter estimate=0.21, 95% confidence interval [CI]=0.09, 0.33); this association persisted over time. The association between meniscal degeneration and cumulative damage only became statistically significant at the 48-month visit (parameter estimate=0.74, 95% CI=0.18, 1.31).

CONCLUSION

This study illuminates the pivotal role of meniscal degeneration in the early stages of OA, demonstrating its association with increased disease activity and subsequent cartilage damage. The use of MRI-based composite scores provides a powerful tool for tracking disease progression, offering valuable insights for early intervention strategies. By identifying meniscal degeneration as a precursor to osteoarthritis, we can better target preventive measures and therapeutic approaches, ultimately aiming to mitigate the impact of this debilitating condition on patients' lives.