Person holds knee in pain from arthritis, showing a diagram of the knee

Understanding Arthritic Knee Pain

Arthritis is a common condition that affects millions of people worldwide, with knee arthritis being one of the most prevalent and debilitating forms. The knee is a vital joint that bears much of the body’s weight and allows for essential movements such as walking, running, and climbing stairs. When arthritis affects the knee, it can lead to significant pain, discomfort, and a decrease in mobility.

 

How Does Arthritis Cause Pain In The Knee?

To understand how arthritis causes knee pain, it’s essential to first explore the basic structure of the knee joint and how it functions under normal conditions. Our Austin physical therapist is here to shed some light on this topic:

 

The Anatomy Of The Knee

The knee joint is a complex structure composed of three main bones: the femur (thighbone), the tibia (shinbone), and the patella (kneecap). These bones are connected by a network of ligaments, tendons, and muscles that work together to provide stability and facilitate movement. The ends of these bones are covered with a layer of smooth, rubbery tissue known as cartilage. Cartilage acts as a cushion, reducing friction and allowing the bones to glide smoothly against each other during movement.

 

In addition to cartilage, the knee joint contains a thin lining called the synovium. The synovium produces a small amount of fluid that lubricates the joint, further reducing friction and wear on the bones. Together, these components allow the knee to move freely and support the body’s weight without causing pain or discomfort.

 

Person holds up knee to demonstrate how it works

What Happens When You Have Arthritis?

Arthritis in the knee occurs when one or more of these components become damaged or inflamed. There are several types of arthritis that can affect the knee, but the two most common are osteoarthritis and rheumatoid arthritis.

 

Osteoarthritis (OA)

Osteoarthritis is the most common form of arthritis, often referred to as “wear-and-tear” arthritis. It typically develops gradually over time as the cartilage in the knee wears away due to repeated stress and use. As the cartilage deteriorates, the cushioning between the bones decreases, leading to increased friction as the bones rub directly against each other. This bone-on-bone contact can cause significant pain and inflammation, leading to the symptoms commonly associated with knee arthritis.

 

In addition to cartilage loss, osteoarthritis can lead to the formation of bone spurs, or osteophytes. These are small, bony projections that develop around the edges of the joint in response to the increased friction. While bone spurs are the body’s way of trying to protect the joint, they often contribute to further pain and stiffness, particularly during movement.

 

Rheumatoid Arthritis (RA)

Rheumatoid arthritis is an autoimmune disease, meaning the body’s immune system mistakenly attacks its own tissues. In the case of RA, the immune system targets the synovium, causing it to become inflamed. This inflammation leads to the thickening of the synovium, which can then invade and damage the cartilage and bones within the knee joint.

 

Unlike osteoarthritis, which primarily affects the cartilage, rheumatoid arthritis can cause widespread damage to the entire knee joint. The inflammation from RA can also spread to other parts of the body, making it a more systemic condition with far-reaching effects. Over time, the persistent inflammation can lead to significant joint deformity and loss of function.

 

Other Types Of Arthritis

While osteoarthritis and rheumatoid arthritis are the most common types of knee arthritis, other forms can also cause knee pain. These include:

  • Post-traumatic Arthritis: This type of arthritis develops after an injury to the knee, such as a fracture, ligament tear, or meniscus injury. The trauma can damage the cartilage and lead to arthritis over time.
  • Gout: Gout is a type of arthritis caused by the accumulation of uric acid crystals in the joint. It can cause sudden, severe pain and swelling in the knee, often described as a burning sensation.
  • Psoriatic Arthritis: This is an inflammatory arthritis associated with the skin condition psoriasis. It can cause pain, stiffness, and swelling in the knee, along with other joints in the body.
 

The Mechanisms Behind Arthritis Pain

The pain associated with knee arthritis is complex and can result from multiple mechanisms. Here’s a closer look at how arthritis leads to pain in the knee:

  1. Cartilage Degeneration: As the cartilage in the knee wears away, the bones lose their protective cushion. This leads to bone-on-bone contact, which causes pain, especially during weight-bearing activities such as walking or climbing stairs. The lack of cartilage also reduces the knee’s ability to absorb shock, leading to further discomfort.
  2. Inflammation: Inflammatory processes play a significant role in both osteoarthritis and rheumatoid arthritis. In osteoarthritis, inflammation occurs as a response to cartilage damage and the release of enzymes that break down the remaining cartilage. In rheumatoid arthritis, the immune system’s attack on the synovium leads to inflammation that can spread to other parts of the joint. This inflammation contributes to pain, swelling, and stiffness.
  3. Joint Swelling: Inflammation in the knee joint often leads to the accumulation of excess fluid, known as an effusion. This swelling can increase the pressure within the joint, causing pain and limiting the knee’s range of motion.
  4. Bone Changes: The formation of bone spurs in osteoarthritis or the erosion of bone in rheumatoid arthritis can both contribute to knee pain. These changes in bone structure can make the joint feel stiff and painful, particularly when moving or bearing weight.
  5. Muscle Weakness: Arthritis can cause a decrease in physical activity due to pain, leading to the weakening of the muscles around the knee. Weak muscles provide less support for the joint, which can increase pain and make the knee feel unstable or prone to giving way.
 

What Does Arthritis In The Knee Feel Like?

The experience of living with knee arthritis can vary greatly from person to person, depending on the severity of the condition, the type of arthritis, and the individual’s overall health. However, there are some common sensations and symptoms that many people with knee arthritis report.

Man going down stars holding knee in pain

Common Symptoms Of Knee Arthritis

  1. Pain: Pain is the most prominent and often the first symptom of knee arthritis. It may start as a mild ache or discomfort that is noticeable only after physical activity or at the end of the day. As the arthritis progresses, the pain can become more persistent and severe, affecting daily activities. The pain is often described as a deep ache within the joint, though it can also be sharp, especially with sudden movements.
  2. Stiffness: Stiffness is another common symptom, particularly in the morning or after periods of inactivity. This stiffness can make it difficult to bend or straighten the knee fully, and it may take some time to “loosen up” after getting out of bed or standing up after sitting for a while.
  3. Swelling: Swelling in the knee joint is a result of inflammation and the accumulation of excess fluid. The knee may appear visibly larger than usual, and the skin around the joint may feel warm to the touch. Swelling can fluctuate, often increasing after physical activity or prolonged standing.
  4. Decreased Range of Motion: As arthritis progresses, the knee joint may lose its flexibility. You might find it challenging to fully bend or straighten your knee, which can interfere with daily activities such as walking, climbing stairs, or even sitting down and standing up. This decrease in range of motion is often accompanied by a feeling of tightness in the joint.
  5. Creaking or Crackling Sensation: Many people with knee arthritis report hearing or feeling a creaking, crackling, or grinding sensation when moving the joint. This is known as crepitus and is caused by the roughened surfaces of the bones rubbing against each other or by the presence of loose fragments of cartilage within the joint.
  6. Instability or Buckling: Arthritis can weaken the muscles and ligaments that support the knee, leading to a feeling of instability. You might experience episodes where the knee feels like it’s about to give way or buckle, especially when walking on uneven ground or going up or down stairs.
  7. Tenderness: The knee may be tender to the touch, particularly around the edges of the joint. This tenderness can make it uncomfortable to press on the knee or even rest it against a hard surface.
 

The Progression Of Symptoms

Knee arthritis symptoms typically develop gradually and worsen over time. In the early stages, you might only notice mild discomfort or stiffness that comes and goes. However, as the condition progresses, the pain and stiffness can become more constant, making it difficult to engage in regular activities.

 

For some people, knee arthritis symptoms may remain relatively mild, while others may experience severe pain and significant loss of function. The progression of symptoms can be unpredictable, with periods of relative stability followed by flare-ups where symptoms suddenly worsen.

 

The Impact Of Weather On Symptoms

Many people with knee arthritis report that their symptoms are affected by changes in the weather. Cold, damp weather is often associated with increased pain and stiffness, though the exact reason for this is not fully understood. Some theories suggest that changes in barometric pressure can cause the tissues in the knee to expand or contract, leading to increased discomfort.

 

While the weather’s impact on knee arthritis symptoms is not fully understood, it’s a common experience for many individuals, making it an important consideration in daily life.

 

The Emotional And Psychological Impact Of Knee Arthritis

Living with knee arthritis is not just a physical challenge; it can also have a significant emotional and psychological impact. Chronic pain and reduced mobility can lead to feelings of frustration, anxiety, and even depression.

 

Knee arthritis can also lead to anxiety, particularly around movement and physical activity. The fear of causing further damage or experiencing more pain can make you hesitant to move, leading to a more sedentary lifestyle. This, in turn, can exacerbate the symptoms of arthritis, creating a cycle of pain and inactivity.

 

Coping with the emotional and psychological impact of knee arthritis requires a multifaceted approach. It’s important to acknowledge the emotional toll that arthritis can take and seek support when needed. This might involve talking to a healthcare professional, joining a support group, or discussing your feelings with friends and family.

 

Maintaining a positive mindset and focusing on what you can do, rather than what you can’t, can also help. Setting realistic goals, celebrating small victories, and finding new ways to stay active and engaged in life can all contribute to a better emotional outlook.

 

Daily Life With Knee Arthritis

For many people with knee arthritis, the day starts with stiffness and pain. Getting out of bed can be a slow process, as the knee joint may feel particularly stiff after a night of rest. Morning routines, such as getting dressed or walking to the kitchen, can take longer than usual.

 

Throughout the day, the pain may ebb and flow, influenced by activity levels, weather conditions, and other factors. Tasks that involve standing, walking, or bending the knee can be particularly challenging. By the end of the day, the knee may feel swollen and sore, making it difficult to find a comfortable resting position.

 

Knee arthritis can also affect your ability to participate in social and recreational activities. Activities that you once enjoyed, such as hiking, playing sports, or dancing, may become too painful to continue. This can lead to a sense of loss and a decrease in overall life satisfaction.

 

Social events that involve standing or walking, such as attending a concert or visiting a museum, may also become more challenging. The fear of pain or instability may make you hesitant to accept invitations, leading to social isolation.

 

While knee arthritis is a chronic condition that can’t be cured, understanding the condition and its impact can help you manage your expectations and plan for the future. It’s important to stay informed about your condition, listen to your body, and make adjustments as needed to maintain your quality of life.

 

If your knee is keeping you from the activities you love, then it is time to work with a physical therapist at Move Empower Concierge PT. Schedule a FREE discovery session with us today.