Knee Replacement Surgery

There are two types of knee replacement surgery:

• Total knee replacement.  This is the most common type of knee replacement surgery and it involves both sides of the knee being replaced with a prosthesis, usually made from a mix of metal and plastic.  The surgeon will replace the end of the femur and tibia with the prosthesis which should alleviate your pain.  With a total knee replacement, you are less likely to experience any complications compared to a partial knee replacement. 

• Partial (half) knee replacement.  Only 1 side of your knee joint is replaced with a partial knee replacement, usually because the damage to the knee is on 1 side (commonly the inside of the knee).  The surgeon will make a smaller cut than what is required for a total knee replacement, making the recovery time less compared to that of a total knee replacement.

Your surgeon will discuss what the best type of replacement surgery is right for you, taking into consideration factors such as your general health, age and condition of the knee. 

Knee replacement surgery is recommended for patients who are experiencing pain in their knee due to trauma, arthritis, unusual bone growth or other diseases of the joint which cause knee deformity.  If pain does not improve after more conservative treatments such as physiotherapy or steroid injections have been tested, then knee replacement surgery will be discussed with the you.  Generally, when the knee is worn or damaged to the extent that your mobility is reduced and you are in pain even when resting, knee replacement surgery is likely to be recommended.  

Knee replacement surgery is performed either under a general or spinal anaesthetic.  A spinal anaesthetic (epidural) is injected into the spine, or the fluid surrounding the spine, blocking any feeling from your waist down.  You will be awake during the procedure if you have a spinal anaesthetic.  If your surgery is carried out under a general anaesthetic then you will be asleep throughout the procedure.  

The surgery involves making an incision down the front of your knee and trimming the damaged and worn surfaces from the end of the femur and the top of your tibia.  They will then be shaped so the surface of the prosthesis fits over both bones.  The surgeon may also carry out a procedure called patella resurfacing if it is thought necessary.  This involves replacing the back of the kneecap with a plastic button shaped part.  Once the operation is complete, the wound will be closed with either stitches or clips and covered with a dressing.  The knee will be tightly bandaged to help reduce swelling.  In rare cases a splint is used to keep your leg immobile, but you will be encouraged to move your knee as early as possible, usually within 12 – 24 hours after your surgery.  A member of our physiotherapy team (specialist in movement and mobility) will guide you through a set of exercises to help strengthen your knee and aid your recovery.  It is important to follow the physio’s advice to avoid complications or dislocation of the joint.  

The recovery and rehabilitation process plays a crucial role in helping you get back on your feet and returning to an active lifestyle.  Your healing time will be faster and will drastically improve your chances of long-term success with your new knee.  

You will need the use of a walking frame or crutches for roughly 6 weeks post surgery; however, it can take up to 3 months for pain and swelling to settle down, with some people experiencing leg swelling for up to a year.  It can take up to 2 years for a knee to fully recovery after surgery, and during this time, scar tissue will heal and muscles will be restored by regular exercise.  

Everyone’s recovery is different, so it is important to follow the advice of your surgeon.  If you stick to your exercise and rehab regime that has been devised for you, you should notice a significant improvement within 6 weeks, particularly with improved flexion (bending) and strength.  You will be able to walk for longer periods of time and start to feel that you are regaining your independence.  You can return to driving when you can comfortably get in an out of a car and control it properly.  This will usually be around 6 – 8 weeks, but check first with your physiotherapist or doctor whether it’s safe to drive.  Daily activities such as cooking, cleaning and other household chores will become much easier to perform by 6 weeks.  

Bear in mind that even after you have recovered from your knee replacement surgery, extreme movements or sports such as skiing or mountain biking should be avoided due to the risk of falling.