Knee Osteoarthritis an Introduction

Osteoarthritis (OA) is the most common form of arthritis, affecting millions worldwide. It is particularly prevalent in the knee joints. In the United Kingdom, osteoarthritis significantly impacts the health system and the quality of life of many individuals. It is characterised by cartilage degradation, the cushioning tissue within joints, and changes in the bone, often leading to pain, stiffness, and impaired movement.

Recent data suggest that in the UK, approximately 8.5 million people have osteoarthritis, with knee OA being one of the most commonly affected areas. This condition disproportionately affects the ageing population, but it is not exclusive to the elderly; younger individuals, particularly those who are overweight or have suffered previous joint injuries, are also at risk.

Knee Osteoarthritis

Osteoarthritis is a degenerative joint disease characterised by the breakdown of cartilage, the smooth, rubbery tissue that cushions the ends of bones in joints. In knee osteoarthritis, this degradation occurs within the knee joint, one of the body’s most vital and largest joints. As the cartilage wears away, it leads to a bone-on-bone environment, causing pain, swelling, and restricted movement.

The knee joint comprises three primary components:
Femur (thighbone), tibia (shinbone), and patella (kneecap). These bones are connected by ligaments that provide stability, while tendons connect the bones to surrounding muscles, facilitating movement. The entire joint is encapsulated in a membrane lined with synovial tissue, which produces fluid that lubricates and nourishes the cartilage and other tissues in the joint.

Knee osteoarthritis develops due to mechanical, biological, and biochemical factors destabilising the normal balance of breakdown and joint tissue repair. Several factors contribute to this condition:

1. Mechanical Stress:
Repetitive use and high-impact activities can wear down the cartilage over a lifetime. The knee joint is particularly susceptible due to its weight-bearing nature and the demands of daily activities like walking, climbing stairs, and squatting.

2. Biological Changes:
With age, the molecular structure of cartilage changes, reducing its capacity to withstand stresses and heal. The synovial fluid, which lubricates the joint, also diminishes in quality and quantity, worsening the friction and further degrading the cartilage.

3. Inflammatory Processes:
In response to cartilage damage, the synovial membrane can become inflamed, producing enzymes and cytokines that further accelerate the breakdown of cartilage and affect the underlying bone.

Causes and Risk Factors

Several factors contribute to the development of knee OA, ranging from genetic predispositions to lifestyle choices.

Research suggests that genetics play a significant role in the susceptibility to osteoarthritis. Individuals with a family history of OA are at a higher risk, indicating a hereditary component to the disease. Specific genes associated with the structure and strength of cartilage and bone may influence the likelihood of developing OA, making some individuals more prone to the degenerative changes that characterise this condition.

Age is one of the primary risk factors for osteoarthritis, with the incidence of the condition increasing significantly in older populations. As people age, the water content of the cartilage increases, and the protein makeup of cartilage degenerates. Over the years, repetitive use of the joints can irritate and inflame the cartilage, reducing its effectiveness as a cushion and leading to pain and stiffness. Furthermore, the body’s ability to heal and regenerate cartilage diminishes with age, exacerbating the wear and tear.

Several lifestyle and environmental factors also significantly impact the development of knee osteoarthritis:

Obesity: Carrying extra weight stresses weight-bearing joints like the knees. The increased load can accelerate the breakdown of cartilage and exacerbate the progression of OA. Furthermore, fat tissue produces proteins that can cause harmful inflammation in and around the joints.
Previous Knee Injuries: Injuries to the knee, such as ligament tears, bone fractures, and meniscus injuries, can lead to premature osteoarthritis, sometimes years after the injury. Activities that put repeated stress on the knee joint, like jogging, squatting, and lifting heavy objects, can also contribute to OA.
Occupation: Jobs that involve kneeling, squatting, or heavy lifting are particularly high risk for developing knee OA due to the constant stress and pressure on the joints.

Gender and hormones significantly influence the risk of developing knee osteoarthritis. Women are more likely to develop OA than men, especially after the age of 50, which coincides with menopausal changes. This has led researchers to investigate the role of estrogen in joint health, as the decrease in estrogen levels during menopause may contribute to the deterioration of cartilage and the development of OA.

Symptoms of Knee Osteoarthritis

Knee osteoarthritis (OA) manifests through various symptoms that typically progress over time. Recognising these symptoms early can help individuals seek timely medical advice and management, potentially slowing the condition’s progression.

The initial symptoms of knee osteoarthritis are often subtle but gradually become more noticeable:

Pain after Inactivity or Prolonged Activity:
One of the earliest signs of knee OA is pain that appears or worsens after a period of inactivity or following prolonged activity. Light movement often resolves this pain as the joint “warms up.”

Swelling:
Fluid accumulation in the knee joint can lead to noticeable swelling, often more pronounced after extended periods of activity. Swelling can contribute to a sense of stiffness and discomfort.

Joint Stiffness:
Stiffness in the knee, particularly in the morning or after sitting for long periods, is a common early symptom. This stiffness usually eases with movement as the day progresses.

As knee osteoarthritis advances, the symptoms become more severe and can significantly impact functionality and quality of life:

Increased Joint Pain:
The pain becomes more persistent and severe, no longer subsiding with movement as it might have in the early stages. It can become a constant reminder of the condition, affecting all knee movement.

Reduced Mobility:
Joint degradation leads to a decreased range of motion. Activities that once were easy, such as climbing stairs, walking, or bending, become challenging and painful.

Audible Joint Sounds:
Crepitus, a grating, crackling, or popping sound or sensation, may occur during knee movement. These sounds are caused by the rough surfaces of the bones in the joint rubbing together.

The symptoms of knee osteoarthritis can extend beyond physical discomfort, affecting mental health and daily life:

Daily Activities:
Walking, driving, and household chores can become difficult and painful, leading to frustration and decreased activity levels.

Mental Health:
Chronic pain is associated with significant psychological impacts, including depression and anxiety. The persistent discomfort and limited mobility can lead to social isolation and a decreased quality of life.

Sleep Disturbance:
Pain and discomfort can also disrupt sleep, leading to a cycle of pain and fatigue that further affects emotional and physical health.

Diagnosing Knee Osteoarthritis

Diagnosing knee osteoarthritis (OA) involves a combination of clinical evaluation and diagnostic imaging. Early and accurate diagnosis is crucial for managing the condition effectively and slowing its progression.

The typical diagnostic path in the UK follows:

GP Consultations:
The diagnostic process usually begins with a general practitioner (GP) consultation. During this initial assessment, the GP will discuss the patient’s symptoms, medical history, and any familial incidence of osteoarthritis. This discussion helps to rule out other causes of knee pain and to establish a history of the symptom’s progression.

Physical Examinations:
The GP will perform a physical examination of the knee. This may involve assessing the knee’s range of motion, checking for swelling and identifying any sounds the knee makes during movement. The GP will also look for signs of pain and tenderness by palpating certain areas around the knee.

Imaging used to confirm the initial diagnosis include:

X-rays:
X-rays are a primary tool used to diagnose knee osteoarthritis. They can show the extent of joint damage, such as loss of joint space due to cartilage thinning and changes in bone, including spurs (osteophytes) and other abnormalities. X-rays are beneficial for assessing the severity of the disease but are less effective in detecting early osteoarthritis when changes are minimal.

MRI Scans:
Magnetic Resonance Imaging (MRI) scans provide a more detailed image of the knee’s soft tissues, including cartilage, ligaments, and the meniscus. MRI is beneficial when X-ray results are inconclusive or more information about the joint’s condition is required.

Prompt diagnosis allows for earlier intervention, which can significantly help manage symptoms and slow disease progression. Early interventions might include lifestyle changes, physical therapy, and appropriate medications.

Patients can adopt strategies to protect the joint and prevent further damage by diagnosing and treating OA early. These might include modifying activities that exacerbate joint stress, implementing joint protection techniques, and using supportive devices. Early diagnosis helps healthcare providers develop tailored treatment plans that address each individual’s specific needs and severity of the condition. These plans can significantly enhance the quality of life and functionality for those with knee OA.

Treatment Options

Managing knee osteoarthritis involves a combination of non-surgical and surgical treatments tailored to the individual’s specific symptoms, disease progression, and overall health. Effective treatment can alleviate pain, improve joint function, and enhance quality of life.

Non-surgical Treatments

Physiotherapy and Tailored Exercise Programmes:
Physiotherapy is a cornerstone of osteoarthritis management. It includes exercises to strengthen muscles around the knee, enhance flexibility, and improve range of motion. Tailored exercise programmes are designed to reduce stress on the knee while maintaining overall joint health and mobility.

Pain Management:
Pain relief is vital in managing knee osteoarthritis. This can be achieved through:

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs): These medications reduce inflammation and alleviate pain. They can be taken orally or applied topically.
Analgesics: These include paracetamol and stronger painkillers, which help manage pain but do not address inflammation.
Topical Treatments: Gels, creams, and patches that contain anti-inflammatory agents or analgesics can be applied directly to the knee to reduce pain and swelling.

Weight Management and Lifestyle Adjustments:
Maintaining a healthy weight is crucial as excess body weight increases stress on weight-bearing joints, exacerbating pain and accelerating cartilage degradation. Dietary changes and regular exercise tailored to reduce joint stress can significantly relieve symptoms. Lifestyle adjustments may also include ergonomic changes at home and work to ease joint strain.

Surgical Treatments

When is Surgery Considered? Criteria and Patient Suitability:

Surgery is typically considered when non-surgical treatments have failed to relieve symptoms, and the pain significantly impacts the quality of life. Candidates for surgery usually have severe joint damage, as evidenced by imaging tests, persistent pain, and substantial loss of function.

Types of Surgery:

Knee Replacement (Arthroplasty): This involves replacing the damaged parts of the knee joint with artificial components. Total knee replacement is standard, but partial replacement may be an option for some patients.
Arthroscopy: Although less commonly used for osteoarthritis, arthroscopy involves inserting a camera into the knee joint to repair or remove damaged tissue. This is generally more beneficial for other types of knee problems.
Osteotomy: This surgery involves cutting and realigning bones to relieve pressure on the knee joint. It is most suitable for younger patients with limited arthritis.

Post-surgical Recovery and Expectations:

Recovery varies depending on the type of surgery but generally includes a combination of rest, physiotherapy, and a gradual return to activities. Successful knee surgery can significantly reduce pain and improve function, although it is crucial to have realistic expectations about outcomes. Rehabilitation plays a critical role in the success of surgery, with activities and therapy tailored to help patients regain strength and mobility.

New Advances in Treatment

The field of osteoarthritis treatment is evolving, with new advances that offer hope for more effective management of the condition. Regenerative medicine, in particular, has shown significant promise in treating knee osteoarthritis through innovative techniques that aim to repair and regenerate damaged tissue.

Regenerative Medicine Techniques

Stem Cell Therapy:
This treatment involves using stem cells, which can potentially develop into different types of cells in the body. In knee osteoarthritis, stem cells can be injected directly into the knee joint, which may help regenerate worn-out cartilage. The stem cells can be sourced from the patient’s own body (autologous) or donors (allogeneic).

Platelet-Rich Plasma (PRP):
PRP therapy uses injections of a concentration of a patient’s platelets to accelerate the healing of injured tendons, ligaments, muscles, and joints. This way, PRP injections use each patient’s healing system to improve musculoskeletal problems. PRP injections are prepared by taking one to a few tubes of your blood and running it through a centrifuge to concentrate the platelets. These activated platelets are injected directly into the injured or diseased body tissue. This releases growth factors that stimulate and increase the number of reparative cells your body produces.

New Treatments Available

Cingal®:
Cingal® is the first injectable treatment to combine hyaluronic acid with a fast-acting corticosteroid for immediate and extended relief from knee pain due to osteoarthritis. The hyaluronic acid component acts as a lubricant and shock absorber in the knee joint, while the corticosteroid provides rapid pain relief.

Arthrosamid®:
This is a newer type of injection therapy using a non-biodegradable hydrogel (2.5% cross-linked polyacrylamide and 97.5% water) injected into the knee. The hydrogel acts as a cushioning agent that supports the joint, reducing pain and improving mobility. Arthrosamid® is designed to provide a long-lasting treatment solution, potentially delaying more invasive treatments such as knee replacement surgery.

nSTRIDE®:
The nSTRIDE® APS (Autologous Protein Solution) injection is designed to harness the body’s natural healing abilities. This treatment involves drawing blood from the patient, which is then processed to concentrate anti-inflammatory proteins and growth factors. The solution is injected back into the knee joint, aiming to reduce pain and slow the progression of cartilage degeneration.

Living with Knee Osteoarthritis

Living with knee osteoarthritis (OA) can be challenging, but with the right strategies and support, individuals can manage their symptoms effectively and maintain a good quality of life.

Daily Management of Knee Pain

Exercise Regularly:
Low-impact exercises such as swimming, cycling, or walking can help strengthen the muscles around the knee, improve flexibility, and reduce joint pain. It is important to find a balance that does not exacerbate the pain but helps maintain mobility and joint function.

Use Assistive Devices:
Tools such as canes, orthotic devices, or supportive footwear can help redistribute weight away from the affected knee, reduce pain, and improve stability.

Apply Heat and Cold:
Heat treatments, such as warm baths or heating pads, can help relieve stiffness in the knee. Cold treatments, like ice packs, can effectively reduce joint swelling and pain.

Manage Your Weight:
Maintaining a healthy weight is crucial, as excess weight increases stress on your knee joints, worsening pain and accelerating cartilage degradation.

Rest Strategically:
While activity is important, so is rest. Balancing activity with periods of rest throughout the day can prevent overexertion and effectively manage pain levels.

Support Groups and Resources Available

Support Groups:
Joining a support group can provide emotional and practical support. Groups such as Arthritis Action or the Arthritis Foundation offer resources for people living with osteoarthritis, including advice on treatment options and coping mechanisms, and provide a platform for sharing experiences with others facing similar challenges.

Professional Help:
Consulting with healthcare professionals such as chiropractors, physiotherapists, occupational therapists, or registered dietitians can provide tailored advice that addresses individual needs.

Online Resources:
Websites like NHS Choices offer extensive information about managing osteoarthritis, including exercise tips, nutritional advice, and information on accessing treatment and support services.

Long-term Outlook and Quality of Life Considerations

Adjusting Expectations:
Understanding the chronic nature of osteoarthritis and adjusting expectations can help individuals cope better. Setting achievable goals and celebrating small victories can be motivating.

Regular Medical Reviews:
Ongoing medical support and regular reviews can help adjust treatment plans as the condition progresses, ensuring optimal disease management.

Emotional and Psychological Health:
It’s important to address the psychological impacts of living with chronic pain, including depression or anxiety. Consulting mental health professionals can be beneficial in managing these aspects.

Moving Forward

Knee osteoarthritis is a prevalent condition that significantly affects the mobility and quality of life of many individuals in the UK.

Recap:

Understanding the Condition:
Knee osteoarthritis is a degenerative joint disease marked by the gradual breakdown of cartilage, leading to pain, stiffness, and reduced mobility.

Early Diagnosis:
Early and accurate diagnosis through GP consultations and appropriate imaging tests, such as X-rays and MRIs, is critical for effective management.

Treatment Options:
Treatment can range from non-surgical options such as physiotherapy, NSAIDs, and lifestyle adjustments to surgical interventions for more severe cases.

Innovative Treatments:
Advances in stem cell therapy, PRP injections, and hyaluronic acid products like Cingal® and nSTRIDE® offer new hope for managing symptoms and potentially slowing disease progression.

Living with Osteoarthritis:
Practical daily management strategies and support systems are vital for maintaining a good quality of life.

Consultation with Healthcare Providers:

Individuals experiencing symptoms of knee osteoarthritis should consult healthcare professionals to develop a personalised treatment plan tailored to their specific needs. Medical advice should always be sought to explore the full range of therapeutic options and ensure that treatments are adapted as the condition evolves.

For additional support and information, resources are available through the NHS and various arthritis charities in the UK:

NHS Website:
Offers comprehensive guides on managing osteoarthritis, treatment options, and tips for living with the condition.

Arthritis Action:
Provides resources, support groups, and advice on self-management strategies.

Versus Arthritis:
Offers detailed information on treatments, support services, and research updates regarding osteoarthritis.