Meniscal Pathology and Knee Osteoarthritis Dynamics

The menisci are crescent-shaped fibrocartilaginous structures that distribute load, absorb shock and contribute to joint stability within the knee. Pathological changes to the meniscus, including tears, extrusion and degeneration, compromise its biomechanical functions and accelerate cartilage wear, subchondral bone remodelling and osteophyte formation. Meniscal extrusion, in particular, undermines the hoop stress mechanism, allowing increased focal cartilage loading and progressive joint space narrowing. These processes interact with inflammatory mediators, altered subchondral perfusion and synovial changes to drive a self-perpetuating cycle of tissue damage. Advanced imaging modalities and computational methods have deepened understanding of the temporal relationship between meniscal pathology and osteoarthritic progression, highlighting opportunities for early intervention. Clinically, preservation of meniscal integrity through repair or orthobiologic augmentation shows promise in mitigating cartilage loss, while quantitative monitoring via magnetic resonance imaging helps to stratify patients by risk and monitor responses to emerging therapies. A holistic appreciation of meniscal and whole-joint dynamics is essential for developing strategies that delay or prevent disabling osteoarthritis.

Research from Nature Portfolio

Recent studies have applied artificial intelligence to elucidate early structural changes in knee osteoarthritis. In cohorts without lateral disease, machine-learning algorithms have graded radiographs and three-dimensional MRI to quantify medial meniscal extrusion alongside regional cartilage thickness across multiple subregions of the femorotibial joint. Results demonstrate a progressive increase in extrusion width and corresponding cartilage thinning from initial to moderate stages of osteoarthritis. These findings offer novel insights into spatial patterns of degeneration and may inform the design of automated screening tools for early intervention.

Meniscal Pathology and Knee Osteoarthritis Dynamics publication trend

The graph below shows the total number of articles in meniscal pathology and knee osteoarthritis dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Meniscal extrusion: Displacement of the meniscus beyond the tibial plateau edge, indicating loss of circumferential tension and load-bearing capacity.

Hoop function: The ability of the meniscus to convert axial loads into circumferential tensile forces, crucial for even distribution of joint stresses.

Kellgren–Lawrence grade: A radiographic scoring system for osteoarthritis severity ranging from 0 (normal) to 4 (severe joint space narrowing and osteophytes).

Cartilage thickness: The measured depth of articular cartilage layers on MRI, reflecting joint health and integrity of the weight-bearing surface.

Osteophyte: A bony outgrowth at joint margins, commonly seen in osteoarthritis and indicative of altered bone remodelling.

References

1. Degenerative Meniscus in Knee Osteoarthritis: From Pathology to Treatment. Life (2022).
2. Association of AI-determined Kellgren–Lawrence grade with medial meniscus extrusion and cartilage thickness by AI-based 3D MRI analysis in early knee osteoarthritis. Scientific Reports (2023).
3. Association between baseline meniscal extrusion and long-term incident knee osteoarthritis in two different cohorts. Seminars in Arthritis and Rheumatism (2023).
4. The relationship between meniscal pathologies, cartilage loss, joint replacement and pain in knee osteoarthritis: a systematic review. Osteoarthritis and Cartilage (2022).