Total knee replacement is quite a big operation. It is undertaken to treat arthritis of the knee joint.
Arthritis of the knee causes significant pain which can progress to a point that your knee function is seriously impeded by this as well as deformity or instability. When arthritis is advanced, it is not possible to improve this with an arthroscopy (keyhole surgery). When your symptoms do not respond to medication and physiotherapy, a total knee replacement is indicated.
There is not a lot you can do to prepare yourself for a total knee replacement but it is important to remain as fit and as mobile as possible to enable a smoother and more rapid recovery. Training your muscles tends to make the knee pain worse and can be counterproductive.
The knee joint is approached through an incision on the front of your knee and bone is removed by controlled cuts to reshape the deformities of the bones to the normal contour. The bone removed is replaced with the prosthesis with metal in contact with the bone on both sides of the joint and a polyethylene spacer to act as the low friction bearing surface. It is essential to position the implants in a very precise way and a lot of time in the procedure is devoted just to this aspect of the surgery.
Back in the ward you will be given pain relief and a nerve block to help you in the first 24 hours. Aspirin and sequential calf compression is used to prevent blood clots and antibiotics continue for 24 hours. Normally you will be able to take full weight on the operated knee as soon as you are mobilised either on the day or day after your surgery when your drain has been removed. The physiotherapist will work hard with you to assist you in regaining your joint motion and as the mobility improves the pain is reduced. It is often a good idea to go to a specialist rehabilitation unit as the intensive physiotherapy available there can help you rapidly regain your mobility.
All surgeries have risks and the bigger the operation the greater is the risk. The important problems for which strenuous precautions are taken in the peri-operative period are blood clots in the legs and less frequently in the lungs (pulmonary embolus), infection of the wound and nerve injuries. This is not all that can happen but would be the problems that occur directly related to the surgery. Exacerbations of pre-existing health problems which affect you such as heart arrhythmias, diabetes, strokes or gout can be made worse. It is essential in your pre-operative visit to mention any of these problems you may have so all precautions can be taken to minimise any risks from them.
By the time the decision is made to proceed to surgery, you will have tried many non-operative treatments such as injections, physiotherapy and chiropractic and to be considered for an operation, none of these modalities will have been effective. Essentially this is a mechanical problem in your knee so the only real treatment is to replace the damaged cartilage with the prosthesis.