Knee Replacement

What is a knee replacement?

Knee replacements (also referred to as knee arthroplasty) involve removing damaged cartilage in the knee and replacing it with prosthetic components. The procedure usually focuses replacing cartilage at the tips of the femur and tibia bones, and may also include patella (kneecap) replacement. It is typically recommended for people over the age of 55, who have a history of arthritis or wear and tear due to previous activity. It can be an effective remedy for knee joint pain, restoring much-needed mobility in old age.

How does a knee replacement work?

Knee replacements are similar to hip or shoulder replacements in that they require skilled surgeons to remove bone and cartilage before inserting specially produced prosthetic replacements. However, if you require knee arthroplasty, the process will involve more than just surgery. The general knee replacement process is as follows:

1. Firstly, you will have to attend a consultation with your physician. He/she will want to know whether a knee replacement is necessary or whether other solutions could still be used. As a general rule, it is preferable to avoid invasive surgery if possible and your doctor will explore alternate options like enhanced physiotherapy, steroid injections, mosaicplasty and osteotomies.

2. If you decide to proceed with the knee replacement option, you will need to arrange a date for surgery with the practitioner of your choice. It may help to find a clinic or hospital within easy reach of your home to make returning after the procedure easier.

3. Before surgery, you may be advised to strengthen the knee area through stretches and training. You will also be advised on whether to stop any medications which could conflict with the surgical procedure.

4. When your surgery date arrives, a general anaesthetic will usually be administered and an IV line and urinary catheter may also be needed.

5. The surgeon will then make an incision in front of the knee. He/she will then move the patella aside to access damaged cartilage at the tips of the femur and tibia, which they need to remove.

6. A metal prosthetic replacement will be applied, using a form of cement to attach it securely. A third part is often also added to the base of the patella.

7. When the prostheses are in place, your surgeon will close the incision and apply stitches and a dressing. He/she may also add a drain to remove excess fluid from the knee joint.

8. Within two to three days after the surgery, you should be ready to return home.

What are the different types of knee replacement procedures?

The procedure description above is known as a "total knee replacement" and applies to the majority of knee replacements, but it's not the only form this procedure can take. The procedure is referred to as "total" because all three parts of the knee (patella, tibia and femur) are involved and all receive a new prosthetic element.

Historically, the procedure is relatively invasive but cutting-edge methods can radically reduce this aspect of the operation. By using "mini-incision surgery", doctors can access the knee just as easily without causing as much disturbance to surrounding tissues. Alternatively, your surgeon may recommend a partial knee replacement. As the name suggests, this procedure involves only one of the parts of your knee. It is suitable for around 25% of osteoarthritis patients who request knee arthroplasty.

Another option is to replace the patella alone. Also called a "patellofemoral joint arthroplasty", this procedure is quicker and less invasive but is thought to be less effective for dealing with osteoarthritis.

What should I expect after a knee replacement?

If you choose to undergo knee arthroplasty you can expect a noticeable and sustained alleviation in knee pain, leading to improved mobility. However, these improvements usually take a while to become apparent and you should expect a lengthy period of recovery following the operation.

Directly afterwards, patients are often able to mobilise and return home almost immediately. here is usually some inflammation around the incision and the surgical area, which can last for a month or more. Your knee and leg may feel "tired" as well - another side effect of the operation. Generally speaking, this recovery phase should last for six weeks. At that point, you should be able to walk or even swim. However, the healing and adjustment process lasts longer, and your knee will continue to heal for as long as two years. This makes it important to return to leisure activities or work at a moderate pace to avoid any setbacks.