Degenerative Arthritis | Osteo Arthritis

The most common form of arthritis today is degenerative arthritis, which is also known as osteo arthritis (frequently written as osteoarthritis).

Degenerative arthritis is a painful condition which occurs when cartilage within a joint breaks down. To understand why this causes such a problem it is necessary to have a basic understanding of just what cartilage is and what it does.

Cartilage is a tough and rubbery substance which provides a cushion for the ends of your bones within a joint. In normal health this tough but slick material covers the ends of your bones where they meet in a joint so that they do not rub together and wear each other away. Cartilage provides the ideal surface for your bones to glide effortlessly across one another as your joint moves and also acts as a shock absorber to cushion the bones against the impact of everyday movement and pressure. If the cartilage is damaged or degrades then your bones will rub against each other doing often considerable damage to the joint, or even destroying the joint altogether.

Cartilage alone however is not enough for a healthy joint and there are four other important elements which must be present in the correct balance:

• Water. Up to eighty percent of your cartilage is composed of water and this is crucial not only for lubricating the joint, but also for cushioning your bones and absorbing shocks to the joint.
• Collagen. Collagen is a mesh-like connective tissue which helps hold different structures of the body in place and which has excellent elasticity and the ability to easily absorb shocks. Within the joint collagen is also very important because it provides the framework which holds another important element for joint health – the proteoglycans.
• Proteoglycans. Proteoglycans are large oblong shaped molecules which weave their way into the collagen mesh of the joint and act like sponges to suck up water within the joint. Proteoglycans cushion the joint by expelling water under pressure and soaking it up again when that pressure is released. They are also important because their shape and the manner in which they operate allows your cartilage to mould perfectly to the shape of the joint.
• Chondrocytes. The final element in the equation are the chondrocytes which are specialized cells designed to break down and eliminate old collagen and proteoglycan molecules and replace them with new molecules.

These four elements working together enable your joints to operate just like a well oiled machine. If however any one of these elements is missing, or no longer functions efficiently, then your cartilage can become dry, thin and crack leading to a painful arthritic joint. But just what might cause the cartilage to break down?

Primary Degenerative Arthritis

We do not always know why collagen breaks down and when it does so without any identifiable cause we refer to the problem as being primary degenerative arthritis or primary osteo arthritis. In cases of primary degenerative arthritis we do know that the collagen mesh becomes weak and releases the proteoglycans so that they float free in the joint fluid. This leaves the cartilage without its all important sponges to soak up water so that it dries out, thins and eventually begins to crack. What we do not know is why the collagen mesh fails. Here however there are two main theories.

• Overly efficient chondrocytes. The first theory is that the chondrocytes become too efficient at the job of destroying and clearing out old collagen and proteoglycan modules but not as efficient at replacing them, so that both are depleted as they are destroyed faster than they are replaced.
• Overly active chondrocytes. The second theory is the opposite of the first and holds that new molecules are created faster than the old molecules are destroyed. This leads to a build up of fluid sucked into the joint by the excess of proteoglycan molecules which, in turn, washes away the chondrocytes and thus the joint’s repair and replenishment mechanism.

Secondary Degenerative Arthritis

Secondary degenerative arthritis, or secondary osteo arthritis, is caused by any one of a number of different forms of trauma which may be a sudden one-off event or a series of minor events over many years. Common causes of secondary degenerative arthritis include:

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  Degenerative Arthritis

  Sudden injury. Any sort or sudden injury from a serious injury sustained in a car accident to a simple knock on your elbow from a slip at home can damage a joint and lead to arthritis at some point, often much later in life.
• Repetitive injury. If a joint is placed under repetitive stress for any reasonable period of time damage will occur which could lead to arthritis in the future. Such injury is common in dancers, people who play a lot of sport and individuals who spend a long time working at a typewriter or computer keyboard.
• Bone damage. If the end of your bone is damaged, often as the result of trauma, the body will try to repair the damage and will often over-compensate by regrowing extra bone in the affected area. This can result in a lump on the end of the bone which itself damages the cartilage and results in arthritis.
• Bone disease. Bone disease, such as Paget’s disease, can result in fractures to the bone and once again to overgrowth of bone during the healing process.
• Excess weight. One increasing factor in the prevalence of degenerative arthritis is excessive weight as obesity sweeps across much of the western world. Degenerative arthritis is the product of pressure on your joints and carrying around too much weight simply places extra-ordinary stress on the hips, knees and ankles in particular.

Learn more about…

The symptoms of degenerative arthritis

Degenerative arthritis treatment