Quadriceps Exercises and Medication Prior to Surgery
Prior to surgery and post operatively it is important to strengthen the muscles of the leg and to reduce the stiffness. Regular exercises should be undertaken to do this. Static quadriceps exercises consist of tensing the muscle on the front of the thigh whilst the knee is straight. Hold the contraction for 5 to 10 seconds, rest for 5 or 10 seconds and begin again. This should be repeated 10-50 times. Whilst lying on your back the straight leg should be lifted into the air and held for 5 to 10 seconds, then lowered rested for 5 to 10 seconds and repeated 10 to 50 times. Sitting on a high chair or table and bending the knee over the edge will improve knee bending. The good leg may be crossed over the bad one to assist.
Scans and Tests Prior to Surgery
Prior to admission to hospital blood tests, a urine test, a knee X-ray, a chest X-ray and an ECG or heart tracing will be performed. Blood will be cross matched so as to be available for transfusion following surgery. If you wish to arrange for your own blood to be pre-donated and ready for autologous transfusion, this should be done some weeks in advance and will require a trip to the blood bank on several occasions. It is a routine to use blood salvage techniques during and following surgery, which minimises the need for blood transfusions. Minimally access techniques also reduce the need for blood transfusions. This results in blood transfusion not usually being necessary with uni-compartmental knee arthroplasty. Prior to the operation any tablets or medications you take, or allergies you may have to medications, should be brought to the attention of the surgeon. You should stop anti-inflammatory arthritis tablets for one week prior to surgery. Take only Paracetamol for pain relief during this period. Please notify your surgeon and anaesthetist in advance if you are taking any anti-coagulants (blood thinners), hormone replacement tablets, the Pill or suffer from diabetes or any other significant medical condition.
A general anaesthetic is generally used, sometimes a spinal injection is preferred. To be able to completely replace the surface of the knee joint a 5 - 12cm incision is made down the front of the knee and the joint is opened.
Minimally Invasive Surgery - MIS
Minimally invasive surgery involves the use of smaller wound incisions and special instrumentation to enable surgery to be undertaken. These techniques usually result in significant advantages in respect to improve the speed of recovery, speed of mobilization, shorten hospital stay reduce the period off work and reduce the time until functional and sporting activities can be resumed. The techniques also usually reduce the amount of post-operative pain experienced and the need for post-operative pain relief and analgesia. In knee replacement these techniques are applicable and routinely used by Mr. Johnson in uni-compartmental knee replacement and increasingly in Total Knee Arthroplasty.
Once the wound has been developed and the knee exposed. The bony overgrowth, which commonly occurs in arthritis of the knee, is trimmed away and the joint surfaces removed. This involves some shaping of the bone so that the joint replacement components sit firmly on the bone. The components will either be fixed in situ with acrylic cement or for young patients special components with a roughened or porous surface will be used. The bone then grows into the roughened surfaces anchoring it.
Once the total knee replacement has been inserted the knee joint is closed over drainage tubes. These tubes take away the bleeding from the knee. They stay in the knee overnight. The knee will have a dressing afterwards and be bandaged. You will have a drip to administer fluids whilst you do not feel like eating or drinking. A blood transfusion may be given if required. Initially the knee may be painful. Powerful pain-killing tablets and injections will be prescribed. It is usual for these to be required regularly for 1 or 2 days and for 1 to 2 weeks intermittently, so do not be afraid to ask if you are in pain. Further blood tests and X-rays will be taken. Injections or tablets to thin the blood and to prevent thrombosis will be given.
The recovery from the operation requires about 3 - 7 days in hospital. In this time physiotherapy is commenced. Initially the leg will be placed on a continuous passive motion machine to gently move the knee through a pre-set range of motion. In addition, exercises to improve the strength of the quadriceps muscles are performed.
Wound Dressing and Sutures
The crepe bandage, which is applied in theatre, may be removed after 4 days if the wound is satisfactory. The general practitioner or practice nurse should remove the sutures after 14 days. Sometimes arrangements are made for patients to return directly to the hospital for this.