Partial Knee Replacement

What is partial knee replacement?

Partial knee replacement surgery, also known as unicompartmental knee surgery, is a procedure that involves resurfacing bone and cartilage that has been damaged by osteoarthritis. This is done with metal and plastic components and aims to reduce pain and increase mobility for the patient.

Partial knee replacement is performed through a small incision. This is a smaller scale operation than a total knee replacement, as only a portion of the knee joint is being replaced. Hence, this type of surgery is only appropriate for some patients.


What is osteoarthritis?

Osteoarthritis is the most common form of arthritis and involves the cartilage in the knee (and other joints) wearing away over time. Osteoarthritis can cause swelling, pain, and restricted movement. While some treatments can slow down the progression of osteoarthritis, the damage that occurs in the joint is irreversible, and therefore surgery is sometimes required.

How common is knee osteoarthritis?

Osteoarthritis affects approximately 9-11% of Australians, which is roughly 2.2 million people. That number is expected to increase by almost half by 2032, due to our ageing population. Knee osteoarthritis makes up a sizeable portion of that grouping.

Partial knee replacement surgery

Pre-operation: How to prepare for a partial knee replacement

Preparing for partial knee replacement surgery will involve tests and scans, to assess your suitability for the procedure. That will likely include blood tests, X-rays, and an ECG. Dr. Rahme will discuss these requirements with you, as each patient’s situation is different. Your anaesthetist will also explain the anaesthetic that will be used during your surgery.

Surgery: What to expect?

You will be admitted to the hospital on the day of your operation. Dr. Rahme will visit you in the ward to discuss your surgery and answer any additional questions you might have. Dr. Rahme will also mark your knee with a pen, in preparation.

When it’s time for your surgery, your anaesthetic will be administered. A tourniquet will be applied to your thigh and an antiseptic solution applied to your knee. Sterile sheets will also be draped across your leg, ensuring that only your knee is exposed. This minimises any chance of infection.

Dr. Rahme will make an incision at the front of the knee and will insert the newest implant systems to the damaged part of your knee joint. As Dr. Rahme uses the latest techniques, the procedure will be as minimally invasive as possible.

Once the implant system has replaced the damaged part of the knee joint, the incision will be closed with stitches and the knee wrapped in sterile bandages.


Immediately after your surgery, you’ll be monitored in the recovery ward, until you wake up fully. You will be returned to your ward and depending on how you are feeling after surgery, you may be able to begin walking on the same day while supervised by a physiotherapist.

You will receive blood-thinning medication to reduce the risk of blood clots, which may form in the legs. In addition, you’ll have to wear compression stockings and an inflatable sleeve will compress your calves/feet intermittently. That prevents your blood flow from being too stagnant.

The dressings on your knee will be replaced 24 hours after your operation and once you have the right amount of mobility in your knee, and your pain is under control, you will be discharged. Usually this can be from two to four days after the surgery.

Risks and Complications

Partial knee replacement is still considered major surgery, so it does come with some risks and the potential for complications. However, the likelihood of these complications occurring is very low. Dr. Rahme will discuss these risk factors with you.

Partial knee replacement recovery and timeline

The recovery and rehabilitation period after partial knee replacement is shorter than with a total knee replacement. After your procedure, you can expect to be back to your usual daily activities within three to six weeks.