Frequently asked Questions and Answers

Knees – Questions

What causes arthritis in the knee?

Osteoarthritis or Degenerative Joint Disease is the most common type of arthritis. Osteoarthritis is also known as “wear and tear arthritis” since the cartilage simply wears away. Very much like your brake pads on your car wearing away and when the bare metal is exposed you feel the metal rubbing on application of the brakes. This compares with the arthritic knee when weight or load is put on the joint; patients feel it grating as the bone rubs on bone. The most common cause for osteoarthritis of the knee is genetic, since the quality and durability of each individual’s articular cartilage is dependent on inheritance. Previous injury and surgery for torn meniscus can predispose to arthritis of the knee.

Inflammatory Arthritis causes swelling and heat of the joint lining (synovium) causes a release of chemicals which soften and destroy the cartilage. Rheumatoid arthritis, Lupus and Psoriatic arthritis are inflammatory in nature.

What is the difference between total knee replacement and uni compartmental knee resurfacing?

Total Knee Replacement (TKR) is removing the worn surfaces of the whole joint very precisely and replacing these surfaces with a metal covering / capping of the joint. This includes resurfacing the patella (knee cap). In partial / uni compartmental knee replacement, only the worn part, most commonly the medial (inside) of the knee is worn in such a way that it can be replaced in isolation with a good outcome.

What is revision knee surgery? How is it different to the knee replacement?

At revision surgery the original components/implants are removed and new components are put back in. The technical aspects of the surgery are more complex than the original total knee replacement. There are situations when there is loss of bone and this requires replacement with bone grafting and reconstruction. The preparation for surgery and details should be discussed with you by your surgeon.

What happens if my knee gets infected?

If a knee is confirmed to be infected the patient is first treated with specific antibiotics. If the infection does not clear up, the original components are removed and a block of acrylic cement with antibiotics, known as a “spacer block” is inserted into the knee joint for six to twelve weeks, to help the infection be treated. During this time the patient is given intravenous (I.V.) antibiotics to which the infecting bacteria (germs) are sensitive to. After a minimum of six weeks but usually twelve weeks, a further operation is performed to remove the spacer block, clear all debris and ensure that the knee is clear of infection and safe to put in the new components.

Will my new knee feel different?

There may be some numbness in the skin around your incision. The knee will feel stiffness and swollen over the first few weeks, particularly with excessive exercise and bending activities. Improvement of knee movement is one of the objectives of total knee replacement, but restoration of full motion is uncommon. Most patients can expect to almost fully straighten the knee after replacement and to bend the knee enough to go up and down stairs and get in and out of a car. Kneeling is usually uncomfortable, but it is not harmful to the knee replacement. Some patients feel a sensation of clicking of the metal on the plastic when bending the knee or on walking. These minor symptoms usually improve with time or become insignificant relative to the pain and disability experienced prior to the knee replacement.

Hips – Questions

What causes hip arthritis ?

The most common reason for hip replacement is osteoarthritis. This may be caused by wear and tear of the articular cartilage of unknown cause and may be related to family history. But it can also be secondary to other conditions such as rheumatoid arthritis, avascular necrosis, a fracture or dislocation affecting the hip joint and rarely bone tumours.

What is a hip replacement?

A hip replacement involves an operation to replace part or all of a diseased or damaged hip joint with an artificial hip joint. The operation to replace or treat a joint is known as ‘Arthroplasty’. The aim of a hip replacement is to alleviate pain and restore function for the patient.

Are there any contradictions to hip replacements?

Hip replacements may not be advised for patients who with Parkinson’s disease or a significant weakness of the muscles as in Polio. Also if there is active infection in the hip joint.

When is a hip replacement necessary?

A hip replacement becomes necessary to alleviate pain and increase mobility if the damaged hip joint as a result of disease or injury is no longer responding to conservative treatment Such as pain relief with tablets, using walking aids regular exercise and physiotherapy.

Will my knew hip feel different?

The pain should be reduced or completely abolished. There may be some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending. These improve with time and most patients find these are minor compared with the pain and reduced function they had prior to the hip surgery.