Knee Arthrosis. Why does it happen? What can I do?

Knee osteoarthritis, or gonarthrosis, is one of the most common and debilitating joint conditions. This pathology affects 10% of the world's population over the age of 60, but it does not spare even the youngest. According to recent studies, up to 14% of people between the ages of 25 and 45 show radiographic signs of knee osteoarthritis, often linked to trauma or genetic factors. (Hunter DJ et al., Nature Reviews Rheumatology, 2023) . Gonarthrosis is not a simple consequence of aging, but a condition influenced by multiple factors that we can, in part, control. Let's analyze them in detail.

1. Age: The Inevitable, But Not Definitive Factor

Age is the main risk factor for the development of knee osteoarthritis. As we age, articular cartilage loses elasticity and resistance, making the joints more susceptible to wear. However, age is not the only determining factor. For example, women are more affected than men after the age of 50, a fact linked to the decline in estrogen during menopause. These hormones play a protective role on articular cartilage, explaining the increase in cases of gonarthrosis in older women. (Hochberg MC et al., Lancet, 2022) .

Fun Fact: Some studies have shown that individuals with an active lifestyle and good muscle mass tend to develop osteoarthritis at a later age than sedentary individuals, proving that healthy aging can make a difference.

2. Overweight: A Powerful Enemy of Joint Health

Overweight and obesity are among the main modifiable factors for preventing knee osteoarthritis. Each excess kilogram generates a load of up to 5 kg on the cartilage during activities such as walking or climbing stairs. This mechanical stress accelerates cartilage wear and promotes joint deterioration. In addition, adipose tissue is not a simple fat deposit: it releases pro-inflammatory cytokines that contribute to chronic inflammation, worsening the joint condition. (Zeng C et al., Journal of Orthopaedic Research, 2022) .

Science Fact: Weight loss is more effective than painkillers in reducing knee OA pain. A study published in the Journal of the American Medical Association (Messier SP et al., 2013) showed that a weight loss of 10% of initial body weight can lead to a reduction in pain of up to 50%, exceeding the benefits of commonly used medications such as paracetamol or anti-inflammatories.

3. Knee Injuries: When the Past Comes Back

Traumatic injuries are another important risk factor for early osteoarthritis. Anterior cruciate ligament (ACL) ruptures, meniscal tears, or periarticular fractures alter the biomechanics of the knee, predisposing to abnormal cartilage wear. Even with surgical treatments and appropriate rehabilitation, the risk of developing post-traumatic osteoarthritis remains high. (Filardo G et al., American Journal of Sports Medicine, 2023) .

Fun Fact: Sports can be a double-edged sword. Although they are essential for maintaining healthy joints, high-impact sports like soccer or skiing can increase the risk of injury, especially if you don't follow adequate physical preparation. Swimming and cycling

are highly recommended.

4. Genetics: A Family Predisposition

Genetics plays a crucial role in the development of knee osteoarthritis. Genome-wide association studies have identified genetic variants that influence cartilage quality, bone morphology, and inflammatory response, increasing individual susceptibility. (Huang H et al., Arthritis Research & Therapy, 2021) .

5. Biomechanical Defects and Work Habits

Bow-knees (bow-shaped) or knock-knees (knock-knees) create an imbalance in joint loading, promoting cartilage deterioration in specific areas of the knee. Work activities that involve heavy lifting or prolonged kneeling postures also increase the risk of gonarthrosis. (Wang Y et al., Osteoarthritis and Cartilage, 2023) .

Fun fact: Walking barefoot on natural terrain, such as sand or grass, helps to better distribute the load on the joints compared to the use of unsuitable footwear. (Paterson KL et al., Journal of Biomechanics, 2022) . In this same perspective, often even an insole can help not to correct how mother nature built us but can reduce our pain by optimizing the support of the entire lower limb.

6. Inflammation and Metabolic Diseases

Conditions such as diabetes and metabolic syndrome promote systemic inflammation, worsening joint health. Recent evidence also shows a correlation between hyperuricemia (high levels of uric acid) and the risk of knee OA. (Liu Q et al., Rheumatology, 2022) .

Science Fact: Antioxidants found in common household products like berries, green tea, and olive oil can reduce inflammation and protect cartilage, but staying away from processed foods and unhealthy diets is an even better strategy.

Stop Osteoarthritis, No, But Slow It Down, Yes. How?

As we have seen, osteoarthritis does not have a single culprit but multiple responsibles that exert their effect over a period of decades until they lead to the fateful diagnosis. So what can I do to avoid being a simple passive spectator?

• Maintain an ideal weight: A balanced diet and regular physical activity can help you maintain a healthy weight, i.e. a BMI less than 25, with the help of specialists if necessary.

• Strengthen your muscles: Targeting your knee muscles, such as your quadriceps and glutes, helps stabilize the joint. Why? Your muscles drive your knee, and the more “fit” they are, the better your knee works. So, what sports are recommended in a nutshell? Freestyle swimming and cycling.

• Avoid excessive movements: If you play sports, pay attention to your technique to avoid injuries. Always use adequate protection.

• See a specialist: If you notice persistent pain or stiffness, it is important to have an early evaluation. The earlier the diagnosis, the more treatments are available.

Conclusion

Knee osteoarthritis is a complex condition that involves multiple risk factors. However, knowing these elements and acting on those that can be modified can make a difference. Don't wait until the pain becomes unbearable: small changes in your lifestyle can protect your joints and improve your future.

Recent References:

1. Hochberg MC et al., “Osteoarthritis 2022 Update.” The Lancet , 2022.

2. Hunter DJ et al., “Osteoarthritis: Pathogenesis and Risk Factors.” Nature Reviews Rheumatology , 2023.

3. Zeng C et al., “The Role of Obesity in Knee Osteoarthritis.” Journal of Orthopedic Research , 2022.

4. Filardo G et al., “Post-Traumatic Osteoarthritis After ACL Reconstruction.” American Journal of Sports Medicine , 2023.

5. Chang AH et al., “Biomechanical Predictors of Knee Osteoarthritis.” Gait & Posture , 2023.

6. Paterson KL et al., “Impact of Barefoot Walking on Knee Biomechanics.” Journal of Biomechanics , 2022.

7. Liu Q et al., “Hyperuricemia and Knee Osteoarthritis.” Rheumatology , 2022.