Knee Osteoarthritis

The three knee bones that are involved in the development of knee osteoarthritis are the femur (thighbone), the patella (kneecap) and the tibia (shinbone). When the osteoarthritis is due to deterioration of cartilage between the patella and the femur, it is referred to as patellofemoral osteoarthritis. If it is the result of deterioration of cartilage between the femur and the tibia, it is known as tibiofemoral osteoarthritis.

Risk Factors

Knee osteoarthritis is a “wear and tear” disease that comes on gradually over time. It is not a traumatic disease that is the result of a single discrete event. However, the following factors are known to increase the risk of developing this disease:

• Age – it occurs most frequently in individuals over age 55. It is more difficult for knee cartilage to heal in older individuals;
• Body Weight – the more overweight the individual, the greater the pressure on the joints and on the cartilage between the joints. As a result, there is more “wear and tear” exerted on this cartilage;
• Heredity – there is some evidence that genetic factors may increase the predisposition to knee osteoarthritis;
• Gender – women are more likely to develop this disease than men;
• Certain repetitive stress injuries of the knee can develop into knee osteoarthritis later on if they are not properly treated (see above for causes of secondary knee osteoarthritis);
• Athletes in certain sports that place extra pressure on the knee are more likely to develop osteoarthritis later in life. Research has also indicated a correlation between the development of the disease and having underdeveloped knee muscles.

Symptoms Of Knee Osteoarthritis

Symptoms of this type of osteoarthritis include:

• Knee pain that becomes more severe during periods of physical activity but decreases during sedentary periods;
• Swelling around the knee, but usually there is no “warm to the touch” feeling around the joint;
• Knee stiffness upon awakening in the morning or after sitting or lying for a while without moving the knee;
• Difficulty using the knees for activities such as climbing or descending stairs or getting into or out of a vehicle;
• In some cases, the patient may hear a “crackling” sound when moving the knee (crepitus);
• A bow-leg deformity is often present, due to the part of the knee joint usually affected

Treatment Of Knee Osteoarthritis

Conservative Treatments

It is important to realize that, once the process of cartilage deterioration has started, it cannot be stopped or reversed. However, doctors can provide a number of suggestions to slow the rate of progression of the disease and reduce the pain and discomfort it causes. These include the following:

• Losing weight will reduce the pressure on the knee joint and reduce the “wear and tear” of the cartilage between the knee bones;
• Use of aids such as a walking stick;
• Use of over the counter anti-inflammatory and pain-relieving medicines (NSAIDs) like Advil (ibuprofen) or Tylenol (paracetamol). Topical NSAIDs should be used initially in preference to tablets. If adequate pain relief is not achieved with topical NSAIDs and paracetamol, then oral NSAIDs and/or opioids like codeine should be added;
• Injections of corticosteroids with a local anaesthetic into the knee to counter inflammation and therefore reduce pain.
• Injecting hyaluronic acid ( a lubricating agent that occurs naturally in the knee) to increase the lubrication of the joint is controversial and not universally recommended;
• Wearing an unloader knee brace to shift the point of contact between knee bones from an area with worn cartilage to one with healthier cartilage;
• In conjunction with one or more of the above courses of treatment, doctors may recommend a course of physical therapy to strengthen knee muscles and improve joint flexibility. A physiotherapist can help with the design of such a program;
• Transcutaneous electrical nerve stimulation (TENS) is sometimes used as an adjunct to other methods for pain relief
• Patients can also consult with occupational therapists. These professionals can suggest changes to their daily routine to perform necessary tasks with less pain. They can suggest modifications to the home and/or gadgets to make activities of daily living easier to perform.

Knee Osteoarthritis Surgery

If the osteoarthritis is very advanced or does not respond to the conservative treatments listed above, doctors may suggest surgery. The following is a brief list of the types of surgery available to treat knee osteoarthritis:

• • Arthroscopic surgery (using a small telescope) to remove damaged cartilage, clean the bone surfaces and perform other necessary tissue repair;
  • Osteotomy to reshape the bones of the knee and reduce the degree of contact between them;
  • Irreversible fusion of a badly damaged, painful or unstable joint in order to eliminate pain.This process is called arthrodesis;
  • Knee replacement surgery in which the joint is replaced with an artificial one made from metal or plastic. This is major surgery with many months of rehabilitation required afterwards. However,it is usually a successful procedure and the patient’s new knee joint will usually last for 20 years or more (unless death occurs first).