Revision Knee Replacement
Why a knee replacement needs to be revised:
Plastic (polyethylene) wear – This is one of the easier revisions where only the plastic insert is changed.
Instability – This means the knee is not stable and may be giving way or not feel safe when you walk.
Loosening of either the femoral, tibial or patella component – This usually presents as pain but may be asymptomatic. It is for this reason why you must have your joint followed up for life as there can be changes on X-ray that indicate that the knee should be revised despite having no symptoms.
Infection- usually presents as pain but may present as swelling or an acute fever.
Osteolysis (bone loss). This can occur due to particles being released into the knee joint that result in bone being destroyed.
Stiffness- This is difficult to improve with revision but can help in the right indications.
Investigations required prior to your surgery
You will be asked to undertake a general medical check-up with a physician
You should have any other medical, surgical or dental problems attended to prior to your surgery
Make arrangements for help around the house prior to surgery
Cease aspirin or anti-inflammatory medications 10 days prior to surgery as they can cause bleeding
Cease any naturopathic or herbal medications 10 days before surgery
Stop smoking as long as possible prior to surgery
Day of Surgery
Further tests may be required on admission
You will meet the nurses and answer some questions for the hospital records
You will meet your Anesthetist, who will ask you a few questions
You will be given hospital clothes to change into and have a shower prior to surgery
The operation site will be shaved and cleaned
Approximately 30 minutes prior to surgery, you will be transferred to the operating room
Surgery is performed under sterile conditions in the operating room under spinal or general anesthesia. You will be on your back and a tourniquet applied to your upper thigh to reduce blood loss. Surgery takes approximately two hours.
The Patient is positioned on the operating table and the leg prepped and draped.
A tourniquet is applied to the upper thigh and the leg is prepared for the surgery with a sterilizing solution.
An incision around 7cm is made to expose the knee joint.
The bone ends of the femur and tibia are prepared using a saw or a burr.
Trial components are then inserted to make sure they fit properly.
The real components (Femur & Tibia) are then put into place with or without cement.
The knee is then carefully closed and drains usually inserted, and the knee dressed and bandaged.
Once stable, you will be taken to the ward. The post-op protocol is surgeon dependent, but in general your drain will come out at 24 hours and you will sit out of bed and start moving you knee and walking on it within a day or two of surgery. The dressing will be reduced usually on the 2nd post-op day to make movement easier. Your rehabilitation and mobilization will be supervised by a physical therapist.
To avoid lung congestion, it is important to breathe deeply and cough up any phlegm you may have.
Your Orthopedic Surgeon will use one or more measures to minimize blood clots in your legs, such as inflatable leg coverings, stockings and injections into your abdomen to thin the blood clots or DVT’s, which will be discussed in detail in the complications section.
A lot of the long term results of knee replacements depend on how much work you put into it following your operation.
Usually you will be in hospital for 3-5 days and then either go home or to a rehabilitation facility depending on your needs. You will need physical therapy on your knee following surgery.
You will be discharged on a walker or crutches and usually progress to a cane at six weeks.
Your sutures are sometimes dissolvable but if not are removed at approximately 10 days.
Bending your knee is variable, but by 6 weeks it should bend to 90 degrees. The goal is to get 110-115 degrees of movement.
Once the wound is healed, you may shower. You can drive at about 6 weeks, once you have regained control of your leg. You should be walking reasonably comfortably by 6 weeks.
More physical activities, such as sports previously discussed may take 3 months to be able to do comfortably.
When you go home you need to take special precautions around the house to make sure it is safe. You may need rails in your bathroom or to modify your sleeping arrangements especially if they are up a lot of stairs.
You will usually have a 6 week check-up with your surgeon who will assess your progress. You should continue to see your surgeon for the rest of your life to check your knee and take X-rays. This is important as sometimes your knee can feel excellent but there can be a problem only recognized on X-ray.
You are always at risk of infections especially with any dental work or other surgical procedures where germs (Bacteria) can get into the blood stream and find their way to your knee.
If you ever have any unexplained pain, swelling, redness or if you feel unwell you should see your doctor as soon as possible.
Risks and Complications
It is important that you are informed of these risks before the surgery takes place
Complications can be medical (general) or local complications specific to the Knee
Medical complications include those of the anesthetic and your general well-being. Almost any medical condition can occur so this list is not complete. Complications include
Allergic reactions to medications
Surgery is only offered once non-operative treatment has failed. It is an important decision to make and ultimately it is an informed decision between you, your surgeon, family and medical practitioner.
Although most people are extremely happy with their new knee, complications can occur and you must be aware of these prior to making a decision. If you are undecided, it is best to wait until you are sure this is the procedure for you.