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Knee replacement surgery FAQs

Jan 4, 2023 | Surgery, Knee

Your knee is a vital joint that depends on bones, ligaments, cartilage, muscle and nerves all functioning well. If your knee joint is worn down or damaged, you may be in pain even at rest and will probably find that your mobility is reduced. 

Knee replacement surgery (known as knee arthroplasty) is an operation that replaces a compromised knee with an artificial joint. Surgery is a serious decision and it’s wise to consider it carefully. Here are some common questions that people ask when contemplating knee replacement surgery. 


What causes the need for a knee replacement?

Osteoarthritis is the most common reason for knee replacement surgery. 

Other conditions that may lead to knee replacement surgery include: 

  • Rheumatoid arthritis
  • Haemophilia
  • Gout
  • Bony growths or other knee deformities. 

Knee injuries may also lead to replacement surgery. 


What are the alternatives to surgery?

In many cases, your treatment team will recommend conservative treatments to ease your knee pain or improve mobility.  

Depending on your situation, conservative treatment may include: 

  • Physiotherapy
  • Weight loss (if necessary)
  • Medication
  • Low-impact exercise
  • Injections (Viscosupplementation, PRP, etc).


When might you need knee replacement surgery?

You may experience significant improvement through conservative treatments. On the other hand, you may find that you’re still dealing with debilitating pain and limited mobility. 

If conservative treatments have not relieved your pain sufficiently, then we start to discuss a  knee replacement. 


What happens in knee replacement surgery?

Your surgeon will remove bone and diseased cartilage from your knee joint where your thigh bone and shin bone meet. We replace those surfaces with metal and plastic implants that enable your knee to flex and bend easily again. 


What are the different types of knee replacements?

A knee replacement can be total or partial. 

A total knee replacement removes all the cartilage and bone and replaces both sides of your knee joint with an implant. A partial knee replacement removes only the damaged part of the knee and leaves the healthy parts alone. The implant replaces only one side of your knee joint.  


What’s a robotic knee replacement?

It’s similar to a traditional knee replacement except that it relies on the assistance of a robotic arm or handheld robotic device to complement your surgeon’s skills by improving accuracy and efficiency. The robot helps to ensure precision by taking measurements, creating 3D models and positioning the right-sized implant accurately.  


What are the risks of knee replacement surgery?

Any surgical or invasive procedure has risks as well as benefits. Occasionally, some people experience complications of knee surgery such as: 

  • An infection of the: 
    • Wound
    • Joint replacement (which may require further surgery)
  • Damage to the bones, ligaments, arteries or nerves around the knee joint
  • Unexpected bleeding
  • Stiffness of persistent pain in the knee
  • Deep vein thrombosis
  • Instability of the new knee joint, which may need corrective surgery. 


How long will my new knee last?

A 2019 systematic review and meta analysis found that 82% of total knee replacements and 70% of partial knee replacements lasted 25 years. 

A 2017 study found that the patient’s age at the time of surgery influences how long their knee (or hip) replacement lasts. Patients aged over 70 at the time of their hip or knee replacement had about a 5% lifetime risk of needing a second surgery. However, men who were in their 50s at the time of their first surgery had a 35% risk of needing a second operation. 

There are a few reasons for that. If you’re in your early 50s when you have your first knee replacement, you’re still at a fairly active stage of life and doing a lot with your knee. You’re probably still working, dashing about after kids or teenagers, enjoying active hobbies or sports and doing a lot of DIY around the house. If your knee lasts 25 years, you’ll be in your mid-70s when it wears out. You’re still young enough to be quite active and need a knee you can rely on. However, if you have your first surgery in your mid-70s, you’d have to hit 100 before you needed a second operation – and your surgeon would be unlikely to risk it anyway by that age. 


What happens immediately after surgery?

Immediately after your surgery, you’ll be taken to the recovery area. You may stay in hospital for a few nights, depending on your particular needs and your overall health. 

Your immediate recovery will involve: 

  • Getting comfortable! Knee replacement surgery can be painful so you might need painkillers or medication to help with your initial recovery.
  • Caring for your wounds (you’ll be shown how to do this). Keeping them clean and dry is important to prevent infection.
  • Preventing blood clots by:
    • Moving your foot, ankle and knee to increase blood flow to your legs
    • Taking blood-thinning medications if prescribed
    • Doing frequent breathing exercises and getting mobile. 
  • Gradually increasing your activity levels under the guidance of a physiotherapist.


How long does recovery generally take?

Patients continue to improve their function up to 12-24 months after their knee replacement. However, in general the first 12 weeks see a rapid period of improvement, and most patients are starting to do some regular exercise by the end of this period, sometimes earlier.  

Throughout this period, you continue doing the exercises prescribed by your physiotherapist and this will help to improve your knee’s range of motion, strength, and endurance. 

Within the first month after your surgery, you should be able to leave the crutches behind. 

After 4 weeks, you’ll find life begins to return to normal. Returning to driving takes up to 6 weeks, and depending on your job you can return to work, plus travel and perform everyday tasks. 

We encourage you to commence low impact exercises such as swimming or riding a stationary bike as soon as you have enough movement. At the 12-week mark, depending on your recovery and goals, you might return to higher impact exercise.


How can Dr Ross Radic help? 

Dr Ross Radic is an experienced orthopaedic surgeon who has performed numerous total and partial knee replacements, enabling patients to move again with comfort and confidence. He offers robotic knee surgery for total and partial knee replacements at Hollywood Private Hospital in Perth. 

If you’d like an opinion on how to improve your knee, please make an appointment



All information is general and is not intended to be a substitute for professional medical advice. Dr Ross Radic can consult with you to confirm if a particular procedure is right for you. A second opinion may also help you decide on the way forward.