What happens when you get arthritis?

What happens when you get arthritis? 

By Roberta

The term arthritis refers to inflammation of the joints, it derives from the Greek words arthro- which means “joint,” and -itis, which means “inflammation”. This is a common and unfortunately very debilitating condition, which generally causes pain and stiffness around the affected joints. There are many different forms of arthritis, all of which carry their own characteristic disease-causing mechanisms and symptoms. In order to better understand and differentiate between them and their course of development, we must first have a clear understanding of our joint anatomy. 

In our body we have three different types of joints: 

• Fibrous joints, such as the joints that keep our skull bones together
• Cartilaginous joint, such as the joints that make up our spinal cord
• Synovial joints, such as the joints in our knees, elbows, hip, wrist etc 

Synovial joints are the most movable joints of all and the degree of movement as well as their role, is predominantly determined by the shape of the bones that come into contact or in other words, articulate. For example our hip joint, which is like a ball in a socket, is really good for weight bearing. The shoulder joint on the other hand, isn’t as stable but allows for a much greater degree of movement, and that is because the head of the humerus doesn’t fit as well into the cupped surface of our shoulder blade protrusion. Weight bearing joints such as the hip are further stabilised and strengthened by a thick network of tendon and ligament fibres, unlike other more movable joints. 

Nonetheless, all synovial joints share some common characteristics. For example, in all cases the bone articulating surfaces don’t touch directly one another, but rather they’re covered by a thin layer of protective cartilage. The layer of cartilage allows for the bones to glide smoothly over one another without damaging the bone. This is further facilitated by the presence of a lubricating fluid, the “synovial fluid”, which cushions the bone ends and contains nutrients to nourish the cartilage layer. The joint and its fluid are ultimately held together and wrapped by muscle tendons and ligaments in a space that known as the “joint capsule”. 

Osteoarthritis

In general, synovial joints are the most susceptible to arthritis, and when any of their functional components becomes affected, swelling, pain and stiffness around the whole joint might occur.  Among all forms of arthritis, osteoarthritis, abbreviated to OA, is the most common. It is known as a degenerative joint disease or “wear and tear” arthritis, and for this reason it is most commonly seen in older adults. The joints that are affected the most are weight bearing joints, such as the hip and knee joints, as well as the furthest joints of our fingers. Overuse of the joint or strain caused by excessive weight can lead to a progressive process of cartilage break down which leaves the bone surfaces exposed and poorly lubricated. Exposed articulating bone surfaces can rub against one another resulting in long term damage to the bone itself. Fluid filled spots (cysts) may form in the bone, bleeding might occur and bone spurs could grow from the bone around the joint and limit its movements. These changes are the cause behind the typical symptoms we see in OA: swelling, pain, stiffness. 

Rheumatoid Arthritis

Rheumatoid arthritis, RA, is slightly different. It is an autoimmune, inflammatory disease, which means that our immune system attacks healthy cells in your body by mistakenly identifying them as foreign. The joints that are most commonly affected by RA are the joints of the hand that are closest to the palm, as well as our ankles. Furthermore, another unique feature of RA is that unlike OA, it tends to affect joints in pairs, rather than individually. This means that a person with RA might complain of pain, redness and swelling in both his knees rather than just one. This feature can be used diagnostically to distinguish the two conditions in the early stages. However, RA involves a much more aggressive inflammatory process than OA, which over time if left unmanaged, can result in significant deformity of the joints. One common sign of RA of the hand joints is a “swan neck deformity”, characterised by increased extension of some of the finger joints which end up looking like the neck of a swan. Because of the immune involvement, RA can also cause less specific symptoms, such as fatigue, general weakness and fevers, and can be associated with other immune, inflammatory conditions. Overall, because of this, RA is a much more debilitating condition than OA and much more difficult to manage long term. 

Gout

The last form of inflammatory arthritis that we will discuss is Gout. Gout is an inflammatory arthritis but not caused by our immune system, nor by overuse. The cause of Gout is in fact the build-up of uric acid from proteins into the joint space. The majority of this uric acid comes from a diet rich in red meat, organ meat, anchovies, sardines and tuna. Be careful though, all these foods are good for us and don’t cause Gout when we eat them according to the advised amounts. Problems of uric acid build-up in our joints occur when we eat these foods in excess and our body cannot keep up with the increased intake. The most commonly affected joints in Gout are our big toe and also our ankles and finger joints, but normally one at a time. Because of this typical pattern, Gout can be easily differentiated from other types of arthritis and managed appropriately. Furthermore, unlike OA and RA, Gout can easily be reversed, and this often involves simple dietary changes. 

Take Home Message

As you have seen, arthritis is quite a large umbrella term for a number of conditions that can affect our joints and cause several forms and extents of damage: starting with simple swelling, but possibly leading to loss of joint range of movement and even loss of joint anatomy. It is therefore important that we do all that is within our control to take care of our joints and avoid any risky lifestyle choices. That being said, medicine today is much better at treating these conditions. New immunosuppressing medications and joint-replacement surgeries have revolutionised some people’s lives, but as always, the best thing we can do is look after ourselves in order to prevent these conditions from happening or eventually, better manage their side effects.