Total patient specific knee replacement is a very successful surgical treatment for arthritic knees. Surgical techniques have been evolving to lessen tissue trauma and improve outcomes.
Patient specific instrumentation is a new approach to surgery that allows your surgeon to use specialised cutting blocks printed from pre-operative MRI images. This results in better implantation, alignment and removal of bone.
Personalized Care
Your knee is unique and a “one size fits all” approach to off-the-shelf knee replacement implants can often cause complications such as pain or stiffness after surgery. This is partly why 1 in 5 patients are not satisfied with their knee replacement surgery.
PSI addresses these problems by ensuring that your surgeon uses instruments that match your knee shape and size. Using high grade medical 3D printing, bespoke tools are designed and made to fit your specific anatomy.
These cutting guides allow your surgeon to cut your bone precisely and eliminate the need for insertion of guide rods into your thigh bone. As a result, the procedure is less invasive and can potentially reduce your time under anesthesia.
PSI may also eliminate the need for a tourniquet during surgery. Instead, a smaller and lighter device may be used that can be released when necessary (but not kept inflated for the entire operation). This will allow more natural movement of your leg and may reduce post-operative swelling.
Reduced Risk
Patients who have a severe knee injury or significant arthritis in two of three compartments of the knee often opt for surgery to relieve symptoms. Knee replacement allows these patients to return to their normal daily activities, but the mechanical parts of the knee can wear out over time, resulting in pain and the need for further surgery.
The Signature knee is designed to minimize the amount of bone that must be removed compared to traditional implants, saving the patient’s femur and tibia bone. Additionally, the knee implant is designed to be lighter, which may also reduce the amount of stress on the knee’s natural cartilage surfaces and thus reduce the risk of loosening.
Patients who have pain limited to one compartment of the knee are sometimes good candidates for a minimally-invasive partial knee replacement procedure (mini knee). This new surgical technique has been around for decades and offers excellent clinical outcomes. However, it is only an option for a small number of patients.
Shorter Recovery Time
Total knee replacement surgery is typically a quality of life decision for those who experience pain that interferes with activities and impedes their ability to function normally. If other non-operative treatment options like pain medication, injections or physical therapy have been ineffective and you continue to experience severe knee pain then surgery may be an option for you.
After sterile preparation of the skin around your knee and inflation of a tourniquet a small incision is made at the front of the knee and with the use of specialized 3-D printed tools very precise cuts are performed to remove damaged parts of your knee joint. This enables the surgeon to create a new joint with a much smaller incision which results in a more rapid recovery.
Several studies have shown that patient specific UKA has improved kinematics compared to common UKA [104,105]. This could be due to the fact that the implant and alignment guide are designed for your anatomy which is believed to improve the coverage of the tibial plateau.
Better Outcomes
Knee replacement surgery reduces knee pain and restores function to patients with osteoarthritis or rheumatoid arthritis. The procedure involves removing damaged bone and tissue, capping the bare bones of your knee with man-made knee implants and restoring the knee's natural alignment.
Your surgeon will use X-rays to determine the extent of your knee damage and identify any shape irregularities that need to be corrected. You will be positioned on your back and may be under general anesthesia, in which a gas puts you to sleep; regional anesthesia, in which a tube delivers medication to the spinal cord numbing you from the waist down; or local anesthesia, in which your surgeon injects a needle around the surgical site to numb it.
Dr Liew performs all total knee replacements using patient specific instrumentation (in Adelaide) using a technique which does not involve rods going into the femur or tibial shaft and uses specialised cutting guides during surgery. This allows for a much easier way to perform the surgery and has shown that it results in better longer term outcomes than conventional total knee replacement methods.