Osteoarthritis (OA) of the Knee

While knee osteoarthritis is most commonly associated with aging, it can also develop earlier in life due to injury, repetitive joint stress, or underlying joint conditions.

Understanding your condition is the first step toward management. Whether your goal is to stay active, reduce pain, or avoid surgery, this guide covers everything from anatomy to advanced physiotherapy rehabilitation.

The knee is one of the largest weight-bearing joints in the body, formed by the thigh bone (femur), shin bone (tibia), and kneecap (patella). Smooth articular cartilage covers the ends of these bones, allowing frictionless movement, while the meniscus acts as a shock absorber between the femur and tibia.

In osteoarthritis, this protective cartilage gradually breaks down. As cartilage thins and wears away, the underlying bone surfaces are exposed to increased friction and load, leading to pain, stiffness, and the formation of bony growths called osteophytes (bone spurs).

• Normal Wear and Tear: Cartilage naturally thins with age, reducing its ability to absorb shock.

• Trauma or Injury: Falls, car accidents, or sports injuries that damage joint structures.

• Repetitive Joint Stress: Occupational or recreational activities that place repeated load on the knee.

• Inflammatory Conditions: Underlying inflammatory arthritis such as Rheumatoid Arthritis or Gout can damage joint surfaces and lead to secondary OA.

Certain factors may increase your likelihood of developing knee osteoarthritis:

• Age: Adults older than 55 years are more prone to developing OA.

• Gender: Women, especially during and after menopause, have a higher risk.

• Obesity: Excess body weight significantly increases the load placed on the knee joint.

• Genetics: A family history of osteoarthritis increases individual risk.

• Diabetes: Associated with increased risk and faster progression of OA.

• High Cholesterol: Linked to increased joint inflammation and cartilage degeneration.

• Autoimmune Disease: Conditions affecting the joints can increase susceptibility to secondary OA.

If left unmanaged, knee osteoarthritis can lead to:

• Chronic Pain: Persistent joint pain affecting daily function and quality of life.

• Joint Stiffness: Progressive stiffness that limits mobility over time.

• Psychological Impact: Depression and sleep disturbances may develop as a result of ongoing severe pain.

• Reduced Mobility: Difficulty walking, climbing stairs, or performing daily activities as the condition progresses.

While osteoarthritis cannot always be prevented, especially with age, you can reduce your risk and slow its progression by maintaining good joint health through:

• Avoiding Tobacco Products: Smoking is linked to faster cartilage degeneration.

• Healthy Diet: Following a balanced, anti-inflammatory diet supports joint health.

• Low-Impact Exercise: Regular low-impact activity helps maintain joint function without excessive strain.

• Protective Equipment: Wearing appropriate protective gear during sports and physically demanding activities reduces injury risk.

Diagnosis of knee osteoarthritis is primarily made through physical examination and imaging tests.

1. Physical Examination

Your physiotherapist will assess joint swelling, tenderness, range of motion, alignment, and gait pattern, comparing both knees where applicable.

2. Imaging and Tests

• X-Ray: Helpful to check for joint space narrowing and any calcium deposits within the joint.

• MRI / CT: Used to identify other possible joint or bone problems not visible on X-ray.

• Blood Tests: Used to rule out other conditions that cause similar symptoms, such as inflammatory or autoimmune arthritis.