Arthritis is a common condition that affects millions of people worldwide. It can cause pain, swelling, and stiffness in the joints, including the knees. Understanding the symptoms and types of arthritis in the knee is crucial for proper diagnosis and treatment.
When it comes to the various aspects of arthritis in the knee, the way it feels can be effected by the type of arthritis itself. As such, we're going to have to look into it's causes, symptoms and the different types of knee arthritis.
What is Arthritis in the Knee?
Arthritis is a disease that leads to pain, swelling, and stiffness in the joints. When it comes to the knee, arthritis can be particularly debilitating. [1] The knee joint is formed by the thighbone (femur), shinbone (tibia), and kneecap (patella), with cartilage acting as a cushion between these bones. The synovial membrane surrounds the joint and lubricates the cartilage, ensuring smooth movement. [2]
Symptoms of Arthritis in the Knee
The symptoms of arthritis in the knee can vary depending on the type of arthritis and its severity. However, some common symptoms include:
What Is Arthritis Knee Pain Like?
Arthritis of the knee often leads to pain and swelling in the joint. This pain can be present throughout the day or worsen with physical activity. Swelling may occur due to inflammation, causing the knee to appear larger than usual. The way in which the pain comes and goes does vary between Rheumatoid and Osteo arthritis.
NB: These are general cases, and there are of course variations.
OA: Typically this can start with effecting a single joint, and worsen over time. [3] Often people will first notice the pain first thing in the morning or after being inactive for some time.
RA: Usually this begins by effecting smaller joints, typically symptoms will "flare" meaning that they can worsen over a period of time and then improve. [4] Typically pain in RA tends to be "symetrical" effecting both sides of the body. Not an isolated joint. The joint may also shown redness and be warm to the touch.
There are a few things that can worsen the pain, cold weather, stress or lifestyle changes. [5]
Arthritic knee pain typically comes on when you: walk on a flat surface, stand up from sitting or climb stairs. [6]
Swelling can vary between types of arthritis, for example, it's more common in rheumatoid arthritis, but does also occur in osteoarthritis.
Arthritis Knee Swelling
With Osteoarthritis knee swelling can often feel hard, this is due to the formation of bone spurs or osteophytes. [7] This can happen in RA, but it is rarer.
Soft swelling occurs in both conditions.
Swelling is typically more noticable first thing in the morning.
With Rheumatoid Arthritis swelling generally coincides with a flare, meaning other symptoms [8] tend to occur such as:
- tiredness
- fever
- general nausea
Stiffness and Limited Range of Motion
Stiffness is a common symptom of knee arthritis, especially after periods of inactivity. You may experience difficulty bending or straightening your knee fully. The range of motion in the affected knee may be limited, making it challenging to perform daily activities.
Cracking or Popping Sounds
Some people with arthritis in the knee may notice cracking or popping sounds when they move their knee. This sensation, known as crepitus, [9] occurs due to the rough surfaces of bones rubbing against each other when the cartilage is damaged. This is common with both of the main types of arthritis as it is a result of the wearing down of cartialage. It may sound similar to knuckle cracking which is also caused by air moving in the joint.
The sensation itself is harmless, despite the common myth that cracking joints can lead to arthritis. It can theoretically damage tendons in smaller joints if the cracking was particularly forceful, but this is normally reserved to deliberate cracking as in the case of knuckles and is particularly rare either way.
Weakness and Instability
As arthritis progresses, the knee joint may become weak and unstable. This can result in a feeling of the knee "giving way" or buckling, making it difficult to walk or engage in physical activities.
All arthritic conditions can cause this although there are some minor differences between the two most common versions RA and OA.
Rheumatoid Arthritis can cause the tendons to weaken, [10] causing the joint to give way more regularly. This is also the case with, trauma induced, infectious forms of arthritis and gout.
Whereas both osteoarthritis and rheumatoid arthritis can cause locking due to the formation of bone spurs. [11] This causes the joint to lock and then give out afterwards.
Deformities From Knee Arthritis
In some cases, arthritis can cause deformities in the knee joint. The knee may appear misaligned, with the legs pointing inward or outward. This can further contribute to pain and difficulty in mobility.
Most commonly with OA the muscles supporting the knee can weaken leading them to point inwards slighlty [12] whereas with RA it isn't quite so simple as damage to the tendons can lead to a range of deformations.
Types of Arthritis in the Knee
There are several types of arthritis that can affect the knee joint. Let's take a closer look at the most common ones:
1. Osteoarthritis (OA)
Osteoarthritis is the most prevalent form of arthritis and commonly affects the knee joint. It occurs when the protective cartilage between the bones wears away, causing the bones to rub against each other. This leads to pain, stiffness, and limited mobility. Osteoarthritis usually worsens over time. [13]
2. Rheumatoid Arthritis (RA)
Rheumatoid arthritis is an autoimmune disease that causes inflammation in the joints, including the knees. It occurs when the immune system mistakenly attacks the synovium, a lining of the joint capsule. RA can lead to pain, swelling, joint deformities, and systemic symptoms such as fatigue and fever. [14]
3. Post-Traumatic Arthritis
Post-traumatic arthritis can develop after a knee injury, such as a torn meniscus, ligament injury, or knee fracture. The damage to the knee joint can lead to the breakdown of cartilage over time, resulting in arthritis symptoms. [15]
4. Gout
Gout is a type of arthritis that occurs due to the accumulation of uric acid crystals in the joints. While it commonly affects the big toe, gout can also affect the knees, causing sudden and intense pain, swelling, and redness. [16]
5. Reactive Arthritis
Reactive arthritis is an inflammatory condition that typically occurs following an infection, often in the genital, urinary, or gastrointestinal system. It can cause joint pain, swelling, and stiffness, including in the knees. [17]
6. Infectious Arthritis
Infectious arthritis, also known as septic arthritis, occurs when a joint becomes infected, usually by bacteria. This can cause severe pain, swelling, and redness in the knee joint. [18]
Diagnosing Arthritis in the Knee
If you suspect that you have arthritis in your knee, it is essential to seek a proper diagnosis from a healthcare professional. They will evaluate your symptoms, medical history, and perform a physical examination. Diagnostic tests such as X-rays, MRIs, or joint fluid analysis may be recommended to confirm the diagnosis and determine the type and severity of arthritis.
Treating Arthritis in the Knee
While there is no cure for arthritis, various treatment options can help manage the symptoms and improve the quality of life. The treatment approach will depend on the type and severity of arthritis, as well as individual factors. Here are some common treatment options:
1. Medications
Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs) may be prescribed to reduce pain, inflammation, and slow the progression of the disease.
2. Physical Therapy
Physical therapy plays a crucial role in managing arthritis in the knee. It involves exercises and techniques to strengthen the muscles around the knee, improve mobility, and reduce pain.
3. Assistive Devices
The use of assistive devices such as knee braces, crutches, or canes can provide support and stability to the knee joint, making it easier to walk and perform daily activities.
4. Joint Supplements
There are several natural joint supplements that have been demonstrated to reduce inflammation and pain particularly in knee osteoarthritis. There have been multiple studies on glucosamine for knee pain and omega 3 looks to be particularly beneficial. Some natural anti inflammatories such as curcumin also appear to have positive outcomes. However, it should be noted that supplements are not a substitute for medical treatment and should be seen as complimentary treatment.
5. Lifestyle Modifications
Making certain lifestyle modifications can help alleviate symptoms and improve overall joint health. Maintaining a healthy weight, engaging in low-impact exercises, and avoiding activities that put excessive stress on the knees can be beneficial.
6. Injections For Knee Pain
In some cases, injections of corticosteroids or hyaluronic acid may be recommended to reduce inflammation and provide temporary pain relief.
7. Surgery
If conservative treatments do not provide adequate relief, surgical interventions may be considered. Joint replacement surgery, such as total or partial knee replacement, can be an option for advanced cases of arthritis.
References
1 - https://www.ncbi.nlm.nih.gov/books/NBK507884/
2 - https://www.ncbi.nlm.nih.gov/books/NBK561512/
3 - https://www.ncbi.nlm.nih.gov/books/NBK482326/
4 - https://pubmed.ncbi.nlm.nih.gov/24334643/
5 - https://www.ncbi.nlm.nih.gov/books/NBK518992/
6 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3766936/
7 - https://pubmed.ncbi.nlm.nih.gov/28031516/
8 - https://www.niams.nih.gov/health-topics/rheumatoid-arthritis/basics/symptoms-causes
9 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6849337/
10 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6406446/
11 - https://directorsblog.nih.gov/tag/bone-spurs/
12 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3435919/
13 - https://www.niams.nih.gov/health-topics/osteoarthritis
14 - https://www.nccih.nih.gov/health/rheumatoid-arthritis-in-depth
15 - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5488839/
16 - https://www.ncbi.nlm.nih.gov/books/NBK546606/
17 - https://pubmed.ncbi.nlm.nih.gov/29763006/
18 - https://rarediseases.info.nih.gov/diseases/6781/infectious-arthritis/
