Understanding Your
Knee Replacement
Before moving on to your pre-operative assessment, please watch the short video below. It explains what knee replacement involves, the expected benefits, possible risks and alternative treatment options.
Understanding Your
Knee Replacement
Before moving on to your pre-operative assessment, please watch the short video below. It explains what knee replacement involves, the expected benefits, possible risks and alternative treatment options.
Placeholder video — this will be replaced with your own recording.
What most people gain
Most people experience meaningful improvements after knee replacement, although every patient's recovery is different.
Better walking
Move more comfortably and confidently over longer distances.
Better sleep
Reduced night pain often means more restful sleep.
Less pain
Most patients experience a significant reduction in knee pain.
Improved independence
Return to everyday activities with greater ease.
Returning to hobbies
Many people get back to the activities they enjoy most.
Improved quality of life
An overall lift in wellbeing and daily comfort.
Possible risks & complications
Every operation carries some risk. Below are the main complications that can occur — most are uncommon, and your surgical team works hard to minimise them.
Bleeding
Some bleeding is expected during and after the operation. Occasionally, it can be enough to mean that you require a blood transfusion. If you have any objection to receiving a blood transfusion, it is important that you let your surgeon and anaesthetist know before surgery.
Infection
Infection of the wound or joint is uncommon (1-2%) but very serious when it occurs. Infection can occur at any point following knee replacement. If it is a superficial infection, it can sometimes be treated with antibiotics alone. However, deeper infections often require further extensive surgery to change one or more of the components of the knee replacement. This redo (or 'revision') surgery is much more invasive, and has a lower patient satisfaction than first-time knee replacement. There are some factors that significantly increase the risk of infection such as smoking, poorly controlled diabetes and recurrent infections elsewhere in the body, for example the chest or urinary tract. It is important to do everything possible to reduce your risk of infection, and in the next section we go through how you can do this.
Persistent pain
Although all patients will experience pain after a knee replacement, it usually settles down over the first few months. A small number of patients continue to experience significant pain beyond this. This may be due to an identifiable cause (for example misalignment or overhanging of the implant), but sometimes it is unexplained. 5% of patients with a knee replacement feel their situation is worse than before the operation, and 1 in 150 develop severe pain, stiffness and loss of use of the knee (complex regional pain syndrome) which can take months or years to resolve and is sometimes permanent.
Stiffness
Some patients experience reduced range of movement in the new joint. This will often improve with physiotherapy over the first few months, but may require a manipulation under anaesthetic where your surgeon will push your knee under general anasethetic to get it to bend more. Sometimes stiffness doesn't improve, and there is often little that can be done in this scenario as operating to remove scar tissue carries the risk of the knee simply laying down further scar tissue and making the situation even worse.
Blood clot (DVT/PE)
A clot may form in the deep veins of the leg after surgery (Deep Vein Thrombosis). Most hospitals will provide you with VTE (venous thromboembolism) prophylaxis, either a tablet or injection that helps thin your blood to reduce the risk of this happening. If a blood clot forms in the leg and then breaks off and travels to the lungs (PE or Pulmonary Embolism), it can be life threatening. Certain patients at higher risk of DVT/PE may need the blood-thinning medication for a longer period of time, but your surgeon/ anaesthetist will discuss this with you.
Medical risks including heart attack and stroke
Any major surgery carries a small risk of heart attack ('myocardial infarction') and a risk of stroke. This is higher if you have certain medical conditions.
Damage to structures around the knee
Around the knee joint there are ligaments, tendons, nerves and blood vessels. Any of these may be damaged during the operation which may lead to further surgery, numbness and/or loss of power in the leg. This may resolve over time, but in the worst case scenario it can lead to permanent disability and loss of function. There is also a small risk, both during and after the surgery, of sustaining a fracture next to the implant that may require further surgery.
Wear or loosening
The implant may eventually need to be revised or replaced. As with any mechanical, moving system, it can wear out over time and the plastic spacer between the metal implants can wear causing loosening of the prosthesis and pain, potentially requiring re-do or revision surgery. This risk is higher the younger and more active you are.
Every operation involves weighing benefits against risks
Your surgeon has already discussed these with you and recommended surgery because together you feel that the expected benefits for you outweigh the risks in your individual circumstances. If you have any doubts about whether you wish to proceed, please do contact your surgical team.
This information is provided to support your understanding before surgery.