Understanding Knee Cartilage Problems and Osteoarthritis (Gonarthrosis)

Knee cartilage problems and gonarthrosis are among the most common causes of knee pain and functional limitations. These issues affect individuals of all ages, with increasing prevalence as age and activity levels rise. Understanding the risk factors, diagnostic nuances, and evidence-based treatment options is essential for managing these conditions effectively.

Incidence and Prevalence: The Numbers Behind the Problem

• Osteoarthritis Prevalence: According to the World Health Organization (WHO), knee osteoarthritis affects approximately 10% of men and 13% of women over the age of 60. In younger populations, cartilage injuries are more common due to sports-related activities.

• Cartilage Injury Statistics: Studies estimate that 60-70% of knee arthroscopies reveal cartilage damage, highlighting its prevalence even among active individuals without osteoarthritis.

Risk Factors

• Age and Gender: Aging is the primary risk factor, with women at a higher risk post-menopause due to hormonal changes.

• Obesity: Every additional kilogram of body weight adds approximately 4 kg of extra pressure on the knee joint, accelerating cartilage degeneration.

• Sports and High-Impact Activities: Athletes, especially those in contact sports, have a higher incidence of cartilage injuries.

• Genetics: Family history plays a role in susceptibility to osteoarthritis and cartilage disorders.

• Biomechanical Factors: Poor alignment, overuse, or prior injuries increase the risk of cartilage damage.

Not Every Knee Pain Is a Meniscus Problem

One of the biggest misconceptions is that all knee pain is related to the meniscus. While meniscal tears are common, cartilage injuries and gonarthrosis are equally significant causes of knee pain. Misdiagnosing the cause can lead to inappropriate treatments and prolonged symptoms.

Surgical Options: Limited Benefits of Cartilage Procedures

While surgeries like microfracture, cartilage transplants, or even knee replacements are available, their benefits can be limited:

• Cartilage Repair Surgeries: Procedures like microfracture or autologous chondrocyte implantation can temporarily improve symptoms, but their success depends on the patient's age, weight, and activity level.

• Knee Replacement: Effective for severe gonarthrosis, but it’s a major surgery with long recovery times and the potential for complications.

• Scientific Insights: A systematic review published in The Lancet (2020) suggests that many cartilage repair surgeries provide only modest pain relief and have a high failure rate in active individuals.

Injection Therapies: Evidence-Based Options

Several injectable treatments are available for cartilage problems and gonarthrosis, each with varying levels of evidence and efficacy:

1. Corticosteroid Injections

Mechanism of Action: Corticosteroids reduce inflammation by inhibiting inflammatory mediators within the joint.

Efficacy: They provide short-term pain relief, typically lasting several weeks. However, repeated use may lead to cartilage damage.

Scientific Evidence: A Cochrane review found that intra-articular corticosteroids offer short-term pain relief but do not improve quality of life or joint space width.

2. Hyaluronic Acid (HA) Injections

Mechanism of Action: HA acts as a lubricant and shock absorber in the joint, aiming to restore the viscoelastic properties of synovial fluid.

Efficacy: Studies show mixed results; some patients experience pain relief and improved function, while others do not.

Scientific Evidence: A systematic review concluded that HA injections have minimal effects on pain and function and may increase the risk of adverse events.

3. Platelet-Rich Plasma (PRP) Injections

Mechanism of Action: PRP contains growth factors that may promote tissue healing and reduce inflammation.

Efficacy: Evidence is inconclusive; some studies suggest improvement in function but not pain, with an associated increased risk.

Scientific Evidence: A Cochrane review found insufficient evidence to support the use of PRP for musculoskeletal soft tissue injuries.

4. Autologous Conditioned Plasma (ACP)

Mechanism of Action: ACP, a refined form of PRP, is rich in anti-inflammatory cytokines and growth factors that may aid in reducing inflammation and promoting healing.

Efficacy: Preliminary studies suggest potential benefits in reducing pain and improving function, but more research is needed.

Scientific Evidence: A 2020 randomized controlled trial indicated that ACP significantly improved pain and function scores in patients with mild to moderate knee osteoarthritis compared to standard PRP or hyaluronic acid.

5. Adipose-Derived Stem Cells (ADSCs)

Mechanism of Action: ADSCs have the potential to differentiate into cartilage cells and secrete anti-inflammatory factors, potentially aiding in cartilage repair.

Efficacy: Research is ongoing; some studies report improvements in pain and function, but long-term efficacy and safety are not well established.

Scientific Evidence: A systematic review highlighted the need for more robust clinical trials to determine the effectiveness of ADSCs in treating knee osteoarthritis.

6. Prolotherapy

Mechanism of Action: Prolotherapy involves injecting an irritant solution into the joint to stimulate the body's healing response.

Efficacy: Evidence is limited and of low quality; some patients report pain relief, but results are inconsistent.

Scientific Evidence: The Arthritis Foundation notes that prolotherapy lacks strong endorsement due to limited research and is not FDA-regulated.

7. Botulinum Toxin Injections

Mechanism of Action: Botulinum toxin may reduce pain by inhibiting neurotransmitter release involved in pain signaling.

Efficacy: Limited studies suggest potential short-term pain relief, but more research is needed to establish efficacy and safety.

Scientific Evidence: A recent study found that botulinum toxin injections provided rapid pain relief, outperforming physiotherapy in short-term pain management.

8. Genicular Artery Embolization (GAE)

Mechanism of Action: GAE involves blocking blood flow to inflamed areas of the knee to reduce pain and inflammation.

Efficacy: Early studies show promise in reducing pain and potentially delaying the need for knee replacement surgery.

Scientific Evidence: A study presented at the Radiological Society of North America's annual meeting reported significant improvements in pain and quality-of-life scores following GAE.

9. Polyacrylamide Hydrogel (Arthrosamid):

Mechanism: Acts as a viscoelastic implant, reducing friction and improving joint lubrication.

Efficacy: Provides long-lasting pain relief (up to 24 months) for mild to moderate knee osteoarthritis.

Scientific Evidence: Early studies show significant improvement in pain and function with a safe profile.

Algorithm for Use

Injections are typically used as part of a stepwise approach:

• Early stages: Hyaluronic acid or PRP.

• Moderate stages: PRP or ACP.

• Advanced stages: May require combined therapies or surgery.

The Role of Exercise: A Cornerstone of Treatment

Exercise is crucial for both prevention and management:

• Strengthening the Quadriceps: Reduces joint load and improves knee stability.

• Flexibility and Range of Motion Exercises: Helps maintain joint mobility.

• Low-Impact Activities: Swimming, cycling, and walking are excellent for reducing stress on the knee while promoting strength.

Scientific Evidence: A meta-analysis published in Arthritis Care & Research (2019) concluded that structured exercise programs reduce pain and improve function in up to 75% of osteoarthritis patients.