Knee Osteoarthritis

What Is Knee Osteoarthritis?

Knee osteoarthritis (OA) is a degenerative joint disease where the cartilage that cushions the knee joint breaks down over time. It's the most common form of arthritis and a leading cause of disability. While often called "wear and tear" arthritis, it's now understood to be an active disease process involving the whole joint.¹

Symptoms²

Pain with activity, especially stairs
Stiffness, especially in morning or after sitting
Swelling
Grinding or crunching sensation
Reduced range of motion
Weakness in leg
May buckle or give way

Risk Factors

Age (more common over 50)
Obesity (major modifiable risk factor)
Previous knee injury
Genetics
Repetitive occupational stress
Female sex
Muscle weakness

Diagnosis³

Based on symptoms and examination
X-rays show joint space narrowing
MRI not usually needed
X-ray findings don't always match symptoms

Treatment

Core Treatments

Exercise (most important!)
Weight management
Education and self-management

Adjunct Treatments

Physical therapy
Pain medications (acetaminophen, NSAIDs)
Topical NSAIDs
Walking aids if needed
Knee braces
Corticosteroid injections

Surgery

Total knee replacement (severe cases)
Usually after conservative treatment fails
High success rate

Exercise for Knee OA

Quadriceps strengthening
Hip strengthening
Low-impact aerobic (walking, cycling, swimming)
Flexibility exercises
Balance training

Weight Management

Every pound lost reduces knee load by 4 pounds
Even modest weight loss helps
Combined with exercise is best

Self-Management

Stay active despite pain
Pace activities
Use heat or cold for symptoms
Good footwear
Avoid prolonged kneeling/squatting

References

Hunter DJ, Bierma-Zeinstra S. Osteoarthritis. Lancet. 2019;393(10182):1745-1759.
Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and knee. Arthritis Rheumatol. 2020;72(2):220-233.
Bannuru RR, Osani MC, Vaysbrot EE, et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis Cartilage. 2019;27(11):1578-1589.