Knee Osteoarthritis (Gonarthrosis)

What is knee osteoarthritis?

Knee osteoarthritis, also known as gonarthrosis, is normal wear and tear of the joint. It affects the cartilage, but also the bone, ligaments, capsule, and muscles. It is a gradual process that develops over several years.

Articular cartilage acts as a cushion between bone surfaces. This is what allows your knee to slide and move smoothly. Over time, this cartilage can gradually wear away.

Osteoarthritis is not limited to cartilage. All structures that form the knee joint can be affected. The bone beneath the cartilage, ligaments, joint capsule, synovial membrane, and surrounding muscles all participate in this adaptation process.

Structures affected by knee osteoarthritis

Here's the good news: osteoarthritis is not a serious disease that destroys your joint. It's a normal adaptive process that develops slowly over years, even decades. This phenomenon can also affect other joints. To learn more about forms of osteoarthritis affecting the back, consult our guide on lumbar osteoarthritis.

What are the symptoms of knee osteoarthritis?

Knee osteoarthritis does not always cause symptoms. Many people live with osteoarthritis without feeling anything. When it becomes symptomatic, you may experience progressive pain, morning stiffness, and cracking in the knee.

This disconnect between osteoarthritis and pain often surprises people. You can have a lot of osteoarthritis visible on imaging and no pain. You can also have little osteoarthritis and many symptoms. To better understand this paradox, check out our article Is it really your osteoarthritis that's causing you pain?

Common symptoms of knee osteoarthritis

Morning stiffness is characteristic of osteoarthritis. It usually improves with movement within 30 minutes. This is a distinguishing feature compared to other joint conditions.

If your symptoms persist for several weeks and affect your daily activities, an evaluation can help you better understand your situation. For knee pain, a quick consultation can help identify the right course of action.

What are the causes and risk factors?

Aging is the main cause of knee osteoarthritis. It is normal to develop it after the age of 50. Certain factors accelerate the process, such as previous injuries, being female, obesity, and physical inactivity.

Osteoarthritis does not develop overnight. It is a process that takes place over several years, often decades. The body gradually adapts to the demands placed on it.

Risk factors for knee osteoarthritis

The good news is that two of these factors can be modified. Regular physical activity and maintaining a healthy weight can have a positive impact on the progression of osteoarthritis. An injury such as a knee sprain or ACL tear can increase the risk of osteoarthritis in the long term.

How is knee osteoarthritis diagnosed?

Knee osteoarthritis is diagnosed based on your symptom history and a clinical examination. X-rays are not mandatory. Importantly, up to 85% of adults without pain show osteoarthritis on X-rays.¹

This statistic is revealing. It shows that what we see on imaging is not always clinically relevant. An X-ray showing osteoarthritis does not automatically mean that this is the cause of your pain.

Diagnostic methods

A healthcare professional can diagnose osteoarthritis of the knee by asking you questions about your symptoms and examining your joint. An X-ray can confirm the diagnosis, but it is not necessary to begin treatment.

When should you see a physical therapist for knee osteoarthritis?

Consult a physical therapist if you have symptoms that limit your daily activities. You do not need to see a doctor first. If your condition requires medical attention, your physical therapist will let you know.

In Quebec, you can see a physical therapist directly without a doctor's referral. This accessibility allows you to get an evaluation quickly. To find out what to expect, check out our article on what happens during a physical therapy evaluation.

Signs that an assessment would be useful

Your physical therapist will assess your situation and determine whether physical therapy can help you. If your condition requires further medical investigation, he or she will refer you to the appropriate professional.

Does Physiotherapy Work for Knee Osteoarthritis?

Physiotherapy is recognized as an effective treatment for knee osteoarthritis, with results supported by scientific research.

Studies show a 70-80% success rate for treating knee osteoarthritis with physiotherapy⁴. The combination of therapeutic exercises, manual therapy, and education is particularly effective in reducing pain and improving function⁵.

Treatment effectiveness depends on several factors: how early you seek consultation (earlier = better results), consistency with home exercises, the severity of osteoarthritis, quadriceps strength, and body weight. A comprehensive evaluation allows us to tailor the treatment to your specific situation.

Most patients notice improvement within the first 4-6 weeks of treatment, with complete resolution typically achieved in 12-16 weeks.

Do you suffer from knee osteoarthritis? Book an appointment for a comprehensive evaluation and a personalized treatment plan.

What are the physical therapy treatments for knee osteoarthritis?

The best treatment for knee osteoarthritis is movement.³ Your physiotherapist will assess why your osteoarthritis is causing pain and will offer mobilizations, specific exercises, and advice on pacing your activities.

Elements evaluated in physical therapy

Physical therapy interventions

Osteoarthritis cannot be cured, as it is a degenerative process that cannot be reversed. However, treatment can completely eliminate the symptoms associated with knee osteoarthritis, even if the osteoarthritis remains present in the joint. Find out what to expect from physiotherapy treatment.

What can you do at home for knee osteoarthritis?

The best thing to do is to stay active. Start with regular walks and mobility exercises, being mindful of any pain. Avoid staying in the same position for more than an hour.

Advice based on your current activity level

Practical tips for everyday life

• Temporarily stop movements that are too painful, then gradually resume them.
• Change position regularly. Do not remain seated or standing for more than an hour.
• Exercise every day according to your tolerance. That's why regular physical activity is so important.

About weight loss

Weight loss is one of the international recommendations for improving the symptoms of knee osteoarthritis. However, weight loss should be a side effect of healthier lifestyle habits, not a goal in itself.

Focus on regular physical activity, a balanced diet, and good sleep. For nutritional guidance, consult a nutritionist.

How can I reduce my chances of developing osteoarthritis of the knee?

Regular physical activity throughout your life is the most important factor. Your joints are nourished by movement, much like a plant needs water. Aim for 150 minutes of cardio per week, strength training twice a week, and maintaining a healthy weight.²

Many people wonder whether certain activities such as running can cause osteoarthritis. Research findings are reassuring. See our article Does running cause osteoarthritis? to learn more.

Canadian Physical Activity Guidelines

These recommendations apply to both young adults and older people. If you already have osteoarthritis, these tips will help reduce your chances of experiencing symptoms.

Other prevention factors

Physical activity remains the number one factor. Your joints become stronger and more resilient through regular movement.

To learn more about osteoarthritis, you can listen to the podcast Parle-moi de santé (Talk to Me About Health) produced by our physiotherapist Alexis Gougeon.

• Listen on YouTube

You can also find the podcast on major podcast platforms. For an overview of what physical therapy is and how it can help you, check out our comprehensive guide to physical therapy.

• Bedson J, Croft PR. The discrepancy between clinical and radiographic knee osteoarthritis: a systematic search and summary of the literature. BMC Musculoskeletal Disorders. 2008;9:116.

• Canadian Society for Exercise Physiology. Canadian 24-Hour Movement Guidelines for Adults Aged 18–64 Years. 2021.

• Hsu H, Siwiec RM. Knee Osteoarthritis. StatPearls. 2023.

• Fransen M, McConnell S, Harmer AR, et al. Exercise for osteoarthritis of the knee. Cochrane Database Syst Rev. 2015;1:CD004376. doi:10.1002/14651858.CD004376.pub3

• 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. doi:10.1016/j.joca.2019.06.011