In this article, we’re going to talk about Osteoarthritis. It is a type of arthritis that most commonly affects joints in the hands, hips, and knees. Knee arthritis is the most rampant out of the three and affects the functionality of the knee joint. Osteoarthritis in the knee causes immense pain and can eventually lead to severe disability of the knee region. Here, we will focus on Osteoarthritis of the knee joint because of how common it is. 

Anatomy of a Joint

This might get a little too technical but stick with us. The more you know your body, the better it is for you to understand how the disease affects you. Before going into Osteoarthritis, we need to understand what synovial joints are and their anatomy.

Osteoarthritis occurs in synovial joints so it will be helpful to know what they are. The bones that form a joint are surrounded by something called the periosteum. This is a very painful and sensitive structure as it contains all the pain receptors. The ends of the bones are surrounded by a shiny substance called the Articular Cartilage which helps in absorbing shock and allows for gliding between bones. 

Around the synovial joint is the synovial membrane which produces the synovial fluid. Around the synovial membrane, there is a fibrous capsule. The membrane and the capsule together form the Articular Capsule. The synovial joint is also further stabilized by ligaments and the number of ligaments depends on which synovial joint it is. There is another cartilage called the meniscus which is a wedge-like structure stuck between the two bones forming the joint. These help with the stability of the joint and in absorbing shock. 

Categorization of Osteoarthritis

The various categories of osteoarthritis are:

  • Primary Osteoarthritis

This is idiopathic in the sense that there is no preceding injury, and the osteoarthritis of the knee is a result of old age and degeneration. 

  • Secondary Osteoarthritis

This is different in the sense that it is usually caused by something else like a congenital abnormality, trauma, and inflammatory arthropathy. 

Signs and Symptoms of Osteoarthritis of the Knee

  1. Pain that is exacerbated with exercise and relieved with rest. The weather has also been shown to influence pain.
  2. Stiffness of the joint.
  3. In severe osteoarthritis, there can be pain even during resting periods or at night.
  4. Similarly, in severe osteoarthritis of the knee, you can also have malalignment of the knee joint.
  5. On examination, there can be muscle wasting. The patient might be overweight.
  6. If you have osteoarthritis, there is tenderness of the joints.
  7. There can be a presence of joint effusion during acute pain.
  8. There is also a reduced joint movement because of stiffness.

Differential Diagnosis of Osteoarthritis of the Knee

Here is all you should know about the differential diagnosis of osteoarthritis. 

1. Septic arthritis

Essentially, bacteria invade the joint space – this is a medical emergency. This is also commonly known as joint infection or infectious arthritis. There is a lot of redness, pain, and heat in that single joint. 

2. Rheumatoid Arthritis

This is diagnosed, especially in the elderly. It is characterized by immune cells attacking the joint tissues and the joint space. 

Rheumatoid Arthritis
Rheumatoid Arthritis

Stages of Osteoarthritis of the Knee

The following is the classification based on severity: 

1. Mild

When you are young and healthy, you are mobile, and your joints are stable and strong. In Osteoarthritis, you have degeneration of the joint. More specifically, you have the degeneration of the Articular Cartilage. This breaks down and is damaged which thereby causes degeneration. This is in the presence of joint space narrowing. This is what is known as mild Osteoarthritis which is quite common when we age.

However, many risk factors predispose and increase the risk of early osteoarthritis of the knee. These include age, obesity, previous joint injuries such as a sports injury, and having a lower leg deformity or malalignment such as bowlegs or knock knees. This essentially means having a valorous feature at the knee joint. There might also be genetic or rheumatic risk factors involved.  

2. Severe

Once mild Osteoarthritis of the knee occurs; progression is inevitable and can be gradual or fast – severe osteoarthritis eventually occurs. Here, you will have bone on bone in the joint structure, with the space between them completely narrowing. There is a total loss of articular cartilage and a subsequent formation of bone spurs called osteophytes. 

However, these are the stages of osteoarthritis of the knee that is generally followed: 

  • Stage 0

This is the stage that is characterized by a normal, healthy, and functioning knee. The joint in the knee shows zero signs of Osteoarthritis and you feel no pain in the day-to-day usage of your knee or the joint. There is no need for any kind of treatment at this stage. 

  • Stage 1

At this stage, you will experience very minor discomfort. Most people ignore this pain and write it off as an age-related problem. It generally will be undiagnosed till this pain progresses to an advanced stage. This stage witnesses the growth of bone spurs which are small bone lumps that grow within joint spaces and tend to pierce into the cartilage over a period. As a precaution, your doctor may give you supplements or recommend lifestyle changes but there is no treatment per se. 

  • Stage 2

In this stage, the growth of the bone spurs exemplifies but does not affect the cartilage yet. This means that the space between the two bones forming the joint is still sufficient. But this is when the discomfort grows into something more pressing and painful. This is the perfect stage for early detection of osteoarthritis of the knee. 

  • Stage 3

This is the moderate stage where the cartilage starts showing signs of damage due to the bone spurs. You will experience continuous and constant pain even while doing mild activities. The doctor will start with physical therapy. If this doesn’t help, he might recommend injecting cortisones. 

  • Stage 4

This is severe osteoarthritis of the knee. Walking or even moving the joint will be extremely painful. The joint space completely diminishes, and the cartilage almost entirely vanishes. Osteotomy is a surgery where they realign your bones. This is generally the recommendation when your osteoarthritis of the knee reaches this stage. 

It is always helpful to be aware and do your research on severe diseases like Osteoarthritis. Never forget, health is wealth. 

Also read- Arthritis