Once the decision has been made to have a knee replacement you will need to attend a pre-operative assessment clinic. Here a registered nurse will give you information about what to expect during your stay in hospital. She will carry out blood tests and/or an ECG and may send you for X-rays. Don’t be alarmed if you need to undergo one or more of these investigations – they are done in your best interest, as the doctors need to know that you are physically able to cope with the surgical procedure.
It is very important to discuss any medication you are taking with the nurse. If you are taking blood-thinners you may need to discontinue them for some time before the operation as they can increase the risk of bleeding and can interfere with your surgery and recovery. You will probably be told not to take aspirin, ibuprofen and all herbal or homeopathic medicines for several days before your operation. You should take your normal medication up to and including the day of surgery unless you have been given specific instructions not to by your anaesthetist or surgeon.
Admission to hospital
You will be admitted to hospital on the day of your surgery. Once you have been admitted, you will be re-examined by a nurse and your orthopaedic surgeon, who will mark your knee and ask you to sign a consent form. You will be measured for anti-embolic stockings (TEDs), which promote circulation in the legs and prevent the formation of Deep Vein Thrombosis (DVT) or blood clots.
*It is very important that you tell the anaesthetist any medication that you are currently taking, or have been taking over the previous few days. There is a chance that certain medications can interfere with the outcome of the procedure, so it is important that you disclose the information. This includes:
- Chronic/repeat medications
- Hormone replacement therapy
- Acute medication (medicines prescribed on a one-off basis)
- Non-prescription drugs such as aspirin, paracetamol or anti-inflammatory drugs.
- Homeopathic and herbal preparations
Anaesthetic and pain management
You will be seen by the anaesthetist before your operation. He will examine you and discuss the type of anaesthetic that will be used. Quite often a spinal anaesthetic is used. You will not be put to sleep for this, but it ensures that you are pain-free during the operation. For a while afterwards you will have no feeling in your legs and won’t be able to move them, but when the spinal wears off, function and feeling will return. Spinal anaesthesia has the advantage of having a lower risk of developing deep vein thrombosis (DVT).
The anaesthetist will discuss pain management with you, if it has not already been done at your pre-operative assessment.
During Surgery - Computer Navigation
Before being taken to the operating theatre you will be asked to change into a rear-fastening gown and the TED stockings. You may be given medication to make you drowsy and more relaxed. Once you have wheeled to the operating theatre, the anaesthetist will administer the anaesthetic and the operation will be performed.
The surgeon uses the latest Computer Navigation technique to precisely cut the bone to remove the arthritic joint and balance the ligaments. This has been shown to correct the overall alignment and implant position more accurately than traditional techniques which should improve the longevity of the implant. The surgeon temporarily places two sensors into the bone above and below the knee, hence the two small additional incisions, which provides information for the Computer Navigation system. The surgeon is then guided by feedback from the system as too the optimum placement of the bone cuts.
The new implants are then securely fixed into place. The main wound is stitched with a soluble suture placed just under the skin so there are no sutures to remove. The two smaller incisions for the sensors are stitched with sutures that are removed at two weeks. The whole procedure takes about one and a half hours