What's new in osteoarthritis pathogenesis?

Area of Science:

• Orthopedics
• Rheumatology
• Musculoskeletal Health

Background:

• Osteoarthritis (OA) is a primary cause of musculoskeletal disability in Western societies.
• A precise definition of osteoarthritis remains challenging, despite its prevalence.
• The correlation between radiographic changes and patient-reported pain in OA is modest.

Purpose of the Study:

• To critically evaluate the definition and understanding of osteoarthritis.
• To explore the role of advanced imaging in redefining osteoarthritis.
• To differentiate between intra-articular and extra-articular factors contributing to OA.

Main Methods:

• The study employed a narrative review methodology.
• A viewpoint analysis focusing specifically on knee osteoarthritis was conducted.
• Consideration of advancements in basic science and imaging techniques.

Main Results:

• Osteoarthritis should be conceptualized as an umbrella term encompassing diverse pathophysiological processes.
• Intra-articular findings (e.g., bone marrow lesions, cartilage defects, meniscal tears) are considered OA.
• Extra-articular factors (e.g., obesity, muscle weakness, vitamin D deficiency) constitute the 'osteoarthritis syndrome'.

Conclusions:

• Recent scientific advancements necessitate a revised understanding of osteoarthritis.
• Distinguishing between intra-articular OA and the broader osteoarthritis syndrome is crucial.
• The development of lesion-specific therapies highlights the importance of identifying individual pain origins.