A Total Knee Replacement (also called Total Knee Arthroplasty, Full knee replacement) is a surgical procedure designed to replace a severely diseased knee joint with an artificial knee joint.
The knee is a hinge joint involving the femur (thigh bone), tibia (shin bone) and patella (knee cap). In a total knee replacement, the ends of the femur and tibia, and sometimes the patella, are surgically removed and replaced with an artificial joint known as a prosthesis.
Total Knee replacement surgery is usually performed when advanced arthritis causes pain and stiffness of the knee joint, seriously restricting movement and quality of life. Total Knee replacement is generally recommended only when other treatments such as medication, physiotherapy and exercise are no longer effective.
Knee replacement may also be necessary to treat knee damage resulting from conditions including rheumatoid arthritis, haemophilia, gout, bone death or bone growth disorders.
A total knee replacement is designed to help with pain and restore the bending movement of the knee.
Computer navigated total knee replacement
During a joint replacement procedure, it is important that everything is aligned properly. Accurate alignment of the knee components is critical to the overall function of your new joint and also plays a role in helping your joint feel healthy again, and helping the joint replacement to potentially last longer. This technique is often used when normal anatomy, alignment and reference points are lost e.g. after a serious injury and leg bones have not healed correctly.
Computer-assisted technology has made it possible for your orthopaedic specialist to navigate joint replacement procedures with a level of accuracy so precise it may improve the results of your surgery.
Computer Navigation technology uses special tracking devices, providing a comprehensive understanding of your joint mechanics in the operating room (OR). Armed with this information, adjustments within a fraction of a degree are made, helping to ensure your new joint has the stability and range of motion needed for a successful replacement. Specifically, the technology uses the latest advancements in science and computer engineering to make the procedure more accurate than joint surgery without it.
As an instrument is moved within your joint, special infrared trackers calculate its position and wireless instruments instantaneously transfer the data to a computer in the OR. This information is then displayed on a monitor as an interactive model of the anatomy or “blueprint” that supplies all the angles, lines and measurements of your unique anatomy. Your diseased bone is then replaced with new, artificial joint components often called prostheses or implants. Joint implants are engineered to replicate a normal, healthy joint.
Patient Specific Instrumentation
Patient specific instruments ensure that the end surgical result matches preoperative planning. 3D modelling from MRI captures true patient anatomy.
3D animation of knee kinematics
Custom guides are designed for each patient from their 3D MRI modelling. This enables the surgeon to assess and take into account each patients unique differences (e.g. height, femoral & tibial alignment and rotation ) prior to surgery to ensure best results.
Decreasing pain and improving recovery time
Inflammation and oedema (swelling) occurs after all types of surgery. Generally the longer the surgery and the more invasive it is (e.g bone cuts in a total knee replacement versus a soft tissue procedure such as a hernia repair) the greater the inflammation and oedema.
Inflammation is a crucial process by which the body heals itself. However, a common cause for delayed recovery and increased pain in a total knee replacement is when there is too much swelling and inflammation. This is combatted in multifactorial ways both during the operation (e.g. local infiltrative analgesia combined with a spinal anaesthetic block) and afterwards on the ward.
Routinely used on the ward is ice and compression with a tubigrip stocking (surgical sock). A more effective technique is the use of a compression and cooling brace which can be manually controlled to the desired pressure and temperature. This is regularly used by professionally athletes to recover more quickly from surgery. Please contact my staff for further information on this prior to surgery
Managing Arthritic Pain and relationship with XR changes
Cartilage degeneration, although fundamental to the progression of osteoarthritis, is not the site of origin of pain. Peripheral nerves generally follow the path of blood vessels, and cartilage contains no nerves or blood vessels. Pain may be from the joint capsule , synovium (lining of capsule which produces fluid) , ligaments or bone as well as in the muscles and soft tissues, which surround and move the joint.
Ordinary radiographs show the effect of degeneration of joint cartilage as narrowing of the space between the surfaces of the articular bone (usually called the “joint space” or, more accurately, the “cartilage space”). However, it is possible to have considerable pain despite a normal-looking cartilage space, or pain can be mild despite marked narrowing.
Common radiographic changes often seen and reported in osteoarthritis such as thickening of the subchondral bone (eburnation) and formation of osteophytes (bone spurs) do not correlate with the presence or the severity of pain. It is important to optimise a conservative management program before considering surgery.
Dental treatment after total knee replacement
It has been common practise in Australia and Internationally to give patients after total knee repalcement or total hip replacement antibiotics prior to dental treatments to decrease the risk of infection of the joint replacement.
Most antibiotic coverage is not evidence based but rather anecdotal, historical or medico-legally based. The decision to cover with antibiotics needs to be individually assessed relative to both the health of the patient and the dental procedure being performed.
If weight is an issue 10% weight loss from diet and exercise can result in a 38% improve in pain and function scores. This should be strongly considered prior to surgery as part of a Pre-Rehabilitation program.
Optimising Conservative Management
Before considering surgery it is important to have exhausted and optimised all non-surgical interventions. Your physiotherapist and GP can help with this. A good place to start and an excellent source of advice is MOVE muscle, bone and joint health.
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