The knee joint is not only the largest and most complex joint in the human body, but also the cornerstone of our walking, running, and free movement. With an aging population and increasing obesity, more than **500 million people worldwide suffer from knee osteoarthritis.**
# 🌍 Global Perspective on Knee Health: From Prevention to Treatment
## â–¶ The Global Burden of Knee Problems
Knee osteoarthritis (KOA) is the most common form of arthritis globally, accounting for **62%** of all arthritis diseases. According to the Global Burden of Disease Study, nearly **600 million people** worldwide suffered from osteoarthritis in 2020, with the knee joint being the most frequently affected.
Knee osteoarthritis is a leading cause of lower limb disability in the elderly, accounting for **1.12%** of healthy life years lost globally. In developed countries such as the UK, the prevalence of knee osteoarthritis increased significantly between 1990 and 2021, with cases in England increasing from 3.02 million to 4.51 million (**an increase of 49.2%**), while cases in Northern Ireland saw a dramatic increase of **76.4%**.
Women are more susceptible to knee osteoarthritis than men, with a prevalence rate **30%-40% higher**. In China, there are over **100 million** osteoarthritis patients, and the prevalence of knee osteoarthritis among people over 75 years old is as high as **80%**.
## â–¶ Causes of Knee Joint Diseases
The occurrence of knee joint problems is the result of a complex interplay of multiple factors. Major risk factors include:
1. **Mechanical Factors**
– **Obesity and Overweight**: Not only do these increase the mechanical load on the knee joint—the pressure on the joint can reach **2-3 times** body weight when going up and down stairs, and even **4-6 times** when running or climbing mountains—they also trigger systemic inflammatory responses that accelerate cartilage destruction.
– **Sarcopenia**: With an incidence rate as high as **25.07%** in patients with knee osteoarthritis, it leads to decreased joint stability and accelerates joint degeneration.
2. **Age and Biological Factors**
– **Aging**: The ability of cartilage to repair itself declines with age.
– **Genetic Factors**: Family history is an important risk factor, especially for arthritis of the hands and hips.
– **Gastrointestinal Microbiome:** Studies have found that gut microbiota dysbiosis may affect joint health through immune mechanisms.
3. **Environmental and Lifestyle Factors:**
– **Trauma and Overuse:** Injuries such as anterior cruciate ligament (ACL) tears are common sports injuries.
– **Smoking and Alcohol Consumption:** The prevalence of sarcopenia among smokers and drinkers is **29.82%** and **30.72%**, respectively, indirectly affecting joint health.
– **Irregular Exercise:** The prevalence of sarcopenia in people with irregular physical activity is as high as **35.20%**. Furthermore, warming up the knee joint before exercise is crucial.
## â–¶ Prevention Strategies for Knee Joint Diseases
Knee joint maintenance requires a multi-layered prevention strategy, addressing the root cause:
1. **Weight Management:**
Weight loss can reduce the incidence of knee osteoarthritis by **25% to 50%**. For overweight individuals, it is recommended to choose exercises with lower joint load, such as swimming and cycling.
2. **Scientific Exercise and Muscle Training**
– **Moderate Aerobic Exercise**: Studies show that the incidence of arthritis among fitness runners is only **3.5%**, while the incidence in sedentary individuals is approximately **10%**.
– **Knee Joint Strengthening Exercises**: Recommended exercises include brisk walking, running, swimming, cycling, yoga, and Pilates. Employ professional training methods and emphasize warm-up.
– **Specific Training Movements**: The “balloon-clamping exercise” follows the four-word mantra of “clamp, hook, lift, stretch,” which can comprehensively activate the muscles around the knee joint. Middle-aged and elderly individuals should exercise **3-5 times** per week, for approximately **30 minutes** each time.
3. **Nutritional Supplementation**
Adults need **1000-1200 mg** of calcium daily, while also ensuring sufficient vitamin D intake. **15-20 minutes** of sunlight exposure daily is sufficient to benefit them.
4. **Prevention of Sports Injuries**
Knee injuries such as anterior cruciate ligament (ACL) injuries require timely and proper treatment. Global expert consensus emphasizes the importance of **early intervention** and **precise care**.
## â–¶ Treatment Options for Knee Joint Diseases
Depending on the severity of the disease, treatment for knee osteoarthritis is divided into several levels:
1. **Conservative Treatment**
– **Physical Therapy**: Focuses on strengthening the muscles around the knee joint and improving joint stability.
– **Lifestyle Modifications**: Includes weight management and adjustments to exercise patterns.
2. **Pharmacological Treatment**
– **Oral Medications**: Nonsteroidal anti-inflammatory drugs (NSAIDs), etc.
– **Intra-articular Injection**:
– **Platelet-Rich Plasma (PRP)**: Suitable for mild to moderate knee osteoarthritis, superior to placebo, hyaluronic acid, and corticosteroids in terms of safety and clinical benefit.
– **Hyaluronic Acid**: Suitable for symptomatic knee osteoarthritis, regardless of age or comorbidities.
– **Corticosteroids**: Can provide short-term symptom relief, but may damage cartilage and accelerate degeneration.
The table below compares the characteristics of mainstream injection treatment methods:
| Treatment Method | Best Indications | Duration of Efficacy | Main Advantages |
|———|————|————–|———-|
| Platelet-Rich Plasma (PRP) | Mild to moderate knee osteoarthritis (KL grade 1-3) | Medium to long-term efficacy | High safety, no chondrotoxicity |
| Hyaluronic Acid | Symptomatic knee osteoarthritis, regardless of age | Short to medium duration | No drug interactions, suitable for patients with multiple comorbidities |
| Corticosteroids | Acute flare-ups, significant inflammation | Short duration | Rapid anti-inflammatory and analgesic effects |
| Cell Therapy (CBT) | Mild to moderate knee osteoarthritis unresponsive to other treatments | Approximately 12 months | No chondrotoxicity, potentially longer-lasting |
3. **Surgical Treatment**
For end-stage knee osteoarthritis, surgical intervention, such as knee replacement surgery, may be considered when conservative treatment is ineffective.
## â–¶ International Expert Recommendations and Consensus
1. **European ESSKA-ORBIT Consensus Recommendation**
– **PRP** is recommended as a first-line biological injectable treatment for knee osteoarthritis.
– **Cell therapy (CBT)** is recommended as a second-line treatment for patients who have failed other non-surgical and injectable therapies and have no indication for surgery.
– **Non-steroidal anti-inflammatory drugs (NSAIDs) are not recommended during PRP treatment; postoperative use of non-anti-inflammatory analgesics (such as acetaminophen) is recommended.
2. **EUROVISCO Group Recommendations on Hyaluronic Acid**
– **Hyaluronic acid injections are suitable for symptomatic knee osteoarthritis, **regardless of age or comorbidities**.
– **Suitable for **early** symptomatic knee osteoarthritis, even with normal radiographic findings, providing a “window of opportunity” for early treatment.
– **Not recommended for **large amounts of joint effusion** (>20 mL) or acute exacerbations.
3. **Global Expert Consensus on ACL Repair**
– A global consensus led by the Department of Sports Medicine at Huashan Hospital emphasizes that the optimal indication for ACL repair surgery is **acute proximal ACL injury** in patients with good ligament stump quality.
– This technique is not limited to adolescents; it can also achieve good outcomes for patients with joint instability but low activity levels.
## â–¶ Summary
Knee health is essential for long-term quality of life. As experts say, “**Mobility is not just about exercise, but also about freedom, independence, and quality of life**.” Paying attention to knee health from a young age, establishing scientific weight management, exercise habits, and nutritional supplementation plans can significantly reduce the risk of knee osteoarthritis.
For patients with symptoms, early diagnosis and timely intervention are crucial to prevent the disease from spreading to the healthy leg. Modern medicine offers a variety of options, from conservative treatment to advanced biological injections. Patients should work closely with medical professionals to develop personalized treatment plans.
> **Key Note**: The medical information provided in this article is for reference only and cannot replace the diagnosis and advice of a professional physician. If you experience knee pain, swelling, or limited range of motion, please seek medical attention promptly for an accurate diagnosis and personalized treatment plan.
We hope this article has helped you better understand and protect your knee health. If you have any questions, please feel free to contact us!