Arthritis (Osteoarthritis, Osteo, OA, Denegeration)

Arthritis is wearing away of the gristle layer that covers the bone ends inside joints. This layer is the ‘shock absorber ‘ layer of the joint and is the gap you see between the bone ends when you look at an Xray. It is also called the chondral layer or surface and 'chondral damage' is where this layer starts to wear and is the beginning of arthritis. As the layer wears the joint becomes less capable of transmitting load smoothly and becomes painful (aching on activity) and swollen and eventually deformed (knock knee or bow leg). The gap on Xray is then reduced.
It can occur at any age after injury to the joint surface and in particular can follow the loss of a significant part of the knee joint 'cartilage' (meniscus).
The most common cause is the aging process where the joint gristle becomes more brittle and much more susceptible to wear and injury. This is called osteoarthritis.
There are also a number of forms of arthritis where excessive inflammation of the joint occurs first, followed by wearing away of the gristle layer (rheumatoid arthritis and psoriatic arthritis are two examples).
Early arthritis causes aching/pain and swelling with weight bearing activity such as walkng and running.
People who are overweight are at much higher risk of knee arthritis and more rapid worsening of already present arthritis. Weight loss is essential if arthritis is present in the knee.
It will usually be necessary to perform weight-bearing X-rays and possibly a bone scan or MRI scan to help diagnose the condition.
Treatment of early arthritis is by weight loss, activity modification and/or reduction, intermittent anti-inflammatory medication (tablets and locally applied creams/gel) and pain tablets.
Physiotherapy exercises and in particular stretches are important to help maintain movement in an arthritic joint and delay the progression of the disease.
Injections of artificial joint fluid (Synvisc) may help ease the arthritic pain.
New techniques of "mosaicplasty" grafts or cartilage cell culture and grafting are available for small well defined areas of cartilage (joint surface) loss in young people where the surrounding joint surface is normal. Cells are taken from the joint and sent to a special lab (only 5 in the world) and the cells are cultured or grown. After about 6 weeks the new cells are transplanted in a second operation back into the damaged joint. These small defects usually follow trauma. This surgery is very complex and is only suitable for a very few types of joint damage.
Early surgical options involve an arthroscopic surgery ‘clean up’ of the arthritic joint but this procedure only helps about 50% of people and the length of improvement is variable. Further surgery can involve an Osteotomy (realigning a bowleg or knock-knee). This operation is suitable for younger people (below aged 40) with severe wear on only one side of the joint. The aim is to realign the knee so that weight is taken on the good side of the knee and no longer on the worn side; rather like realigning a car wheel where the wear is only on one side of the tread. The operation takes about 3 to 6 months to get over and usually crutches are needed for 6 to 8 weeks. Partial or total knee replacement (Knee Arthroplasty) including the new technique of minimally invasive unicompartmental arthroplasty (MIU) with its associated dramatic reduction in post operative pain and length of hospital stay; faster recovery and much smaller surgical scar. If you are a possible candidate for this new procedure I am happy to provide you with a list of Australian surgeons in each state performing this new operation using the same joint that I use. Request this list from the feedback section of this website BUT we cannot give consultations over the web!!
A total knee replacement is major surgery and requires a lot of effort from the surgical team (surgeon, anaesthetist, hospital staff & physiotherapist) and the patient. The operation involves replacing the worn joint surfaces with an artificial joint surface made of Chrome-Cobalt alloy and high density polyethylene (plastic). The normal ligaments are usually retained. Successful results occur when patients are willing to endure quite a bit of uncomfortable stretching and exercise early in their recovery with the help of a good physiotherapist. Unsuccessful results can occur very easily especially when patients can't or won't do these stretches and exercises. They usually think that they will wait until all the pain settles before they will do the stretches. By then its too late! It requires a lot of determination to keep stretching a painful swollen recently operated knee but the rewards of a successful total knee replacement make the effort worthwhile.
Rehabilitation
After a total knee replacement full recovery may take up to 6 months. For a partial knee replacement up to 3 months. Walking, swimming, golf, bowls, social doubles tennis, bike riding, gym are all permitted activities but not running.
How long do knee replacements last?
The 10 year revision rate for total knee replacement is 12% and for partial replacements is 16% and if the replacement has lasted this long then it is likely to last a lifetime! Factors contributing to failure and revision include obesity, overactivity (especially anything that involves running) and being young at the time of the replacement surgery. After a knee replacement there is often numbness on the outer side of the skin cut, clicking on walking or other movements and brief stiffness/discomfort to get going after sitting. These are all normal.
Please read the details under the heading Complications in the General section especially if you are due to have this surgery.