OSTEO ARTHRITIS

OSTEO ARTHRITIS (OA)

OVERVIEW

Osteo arthritis  is the commonest disorder that affects joints and it is caused by the loss of cartilage.  The cartilage is the covering over the ends of bones that provide a smooth gliding surface.  It looks like the flesh of a coconut and has very low friction.  When this cartilage surface is damaged or destroyed the underlying bone becomes exposed.  As more cartilage is lost the bone eventually rubs against the opposite bone within the joint and this is called osteo arthritis.   The condition is generally progressive and results in pain, deformity, and stiffness.   These problems can have a major impact on your quality life and functional activity level.

Inflammatory arthritides such as rheumatoid arthritis are conditions where this cartilage gets damaged due to an abnormality of the lining of the joint called the synovium that is the area where rheumatoid arthritis or inflammatory arthritis pathology first takes place.

FIGURE 1: Normal and Arthritic Knee

There are several contributing factors to the development of OA :

1. Obesity correlates with a significant rise in arthritis because of the increased loads the excessive weight puts on the knee joint.
2. Genetics clearly plays a role.
3. Trauma/Injury results in damage to the cartilage or change the alignment of the bones so that increased force is taken on one side of the joint causing overload and wear.
4. Instability with abnormal joint movement because of ligament damage can lead to overloading of the cartilage and eventual arthritis.
5. Age is associated with osteoarthritis. Although there is an increased frequency of OA in older people not everyone will get OA no matter how old they live.

HOW IS OSTEO ARTHRITIS OF THE KNEE TREATED?

Conservative treatment:
Generally, unless the knee is so badly damaged and function so limited conservative management is recommended as initial management. This may include the following options:

(a) Weight loss: For those overweight, this is a significant factor in improving symptoms.
(b) Muscle strengthening: Pain and function are improved by exercise
(c) Medication: This can include pain medication as well as anti-inflammatories.
(d) Injections: A hydro-cortisone injection may settle symptoms for a period of time. Some patients get long-term relief over a year, whereas others do not get any relief at all. This treatment is usually offered when patients present with very painful and /or inflamed swollen knees. The fluid is often removed at the same time.
(e) Walking aids: A stick can be of great value to unload the knee especially when walking longer distances.
(f) Orthotics: Occasionally we will suggest inserts for your shoes to try to unload the worn side of your knee. These help with about 50% of patients.

PLATELET RICH PLASMA (PRP)

This has been shown to have a good effect on about 65% of patients who do not have end-stage (grade 4) OA.

See link to PRP

SURGICAL OPTIONS

For end-stage arthritis there are generally three surgical possibilities:

1. Osteotomy:
A malaligned joint is realigned by cutting the bone and setting it in a more favorable position to unload the arthritic joint. It is generally reserved for younger patients.

See link to Osteotomy around the Knee

2. Partial Knee Replacement / Unicompartmental Knee Replacement :
This is used where only one side of the joint is worn and the rest of the joint is perfectly normal.

See link to Unicompartmental Knee Replacement

3. Total Knee Replacement:
The commonest surgical procedure for OA of the knee, used for more advanced arthritis and that can involve more than one compartment (side) of the knee; or if there are other contraindications to using a partial knee replacement.

See link to Total Knee Replacement

The decision as to which surgical procedure would be best for you will be discussed with you by your surgeon.