Total knee replacement (TKR) is a surgical procedure in which injured or damaged sections of the knee joint are replaced with artificial parts. It is commonly performed for arthritis of the knee where the joint has become stiff and painful. Initially, Arthritis may be treated with painkillers, anti-inflammatories, physiotherapy and, in the earlier stages, arthroscopy (keyhole surgery). However as the knee progressively wears, joint replacement surgery may be required to relieve the pain and improve mobility.
The surgery involves an incision over the front of the knee and through the quadriceps muscle. The worn surface of the joint is removed including a small thickness of the damaged bone ends of the knee, usually about a centimetre of bone is removed during the operation. The metal of the knee replacement fits over the cut ends of the bone, essentially resurfacing it, The metal implants are fixed to the bone with cement, with plastic between. The operation takes approximately an hour and a half.
The Total Knee Replacement comes in three parts. The femoral component is made of metal alloy and is highly polished. The tibial component is also metal, with a curved plastic insert attached to its upper surface. This forms the new joint with the metal femoral component. The inner surface of the patella (kneecap) is covered with a plastic button, which sits in a shallow groove on the front of the metal femoral component.
After a Total Knee Replacement
With the aid of a physiotherapist you will get out of bed and begin to exercise your new knee replacement. This may be as early as the day of surgery, or the following day, following the enhanced recovery program. With perseverance, you should be able to climb stairs by day 3 and usually go home between day 3 and 5 depending on the speed of your recovery. Post-operative Physiotherapy, range of movement stretches and functional exercises are all very important to gain full function and range of movement of your knee. Commitment to post-operative rehabilitation is key to get the best result from your knee replacement. You will need to continue attending physiotherapy as an outpatient. This can be done closer to your home with one of our recommended group of physiotherapists. For most people it will take around six weeks to be walking reasonably with only one stick and get back to driving a manual car, but three months to fully recover. It is important to remember that an artificial knee is not a normal knee. You should be able to carry out all normal activities of daily living. Although it does not damage the knee replacement, kneeling can be uncomfortable post-operatively. The details of this will be discussed with you. You should be able to get back to golf, a gentle game of tennis, cycling, swimming.
Lifespan of the TKR
The majority of knees last ten to fifteen years with studies suggesting that a Total Knee Replacement in a 70-year-old has around a 94% probability of lasting for 10 years after surgery. If, however, the patient is younger and more active the replacement may not have such a high survival rate, in which case your surgeon will discuss other options with you.