Revision Knee Replacement means that part or all of your previous knee replacement needs to be revised. This operation varies from very minor adjustments to massive operations replacing significant amounts of bone. The typical knee replacement replaces the ends of the femur (thigh bone) and tibia (shin bone) with plastic inserted between them and usually the patella (knee cap).
Pain is the primary reason for revision. Usually the cause is clear but not always. Knees without an obvious cause for pain in general do not do as well after surgery.
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.
Each knee is individual and knee replacements take this into account by having different sizes for your knee. If there is more than the usual amount of bone loss sometimes extra pieces of metal or bone are added.
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-three 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 old implants may need to be completely removed if there is any malalignment, loosening or breakdown of the bone around the implants.
The bone ends of the femur and tibia are prepared using a saw.
Trial components are then inserted to make sure they fit properly.
The real components (Femoral & Tibial) are then put into place with cement.
The knee is then carefully closed and drains usually inserted, and the knee dressed and bandaged.
When you wake, you will be in the recovery room with intravenous drips in your arm and a number of other monitors to check your vital observations.
Once stable, you will be taken to the surgical floor. The post-op protocol is surgeon dependant, but in general your drain will be removed within 24 hours after surgery. Most patients will walk with physical therapy the same day of surgery. You will have a light, waterproof bandage covering the incision. You will be able to bend and move your knee freely. An ice pack will be applied to the knee, directly after surgery and will be changed out and replaced over the course of the post operative period.
To avoid lung congestion, it is important to breathe deeply and cough up any phlegm you may have.
Your Orthopaedic Surgeon will use one or more measures to minimize blood clots in your legs, such as inflatable leg coverings and compression stocking. You will be started on a blood thinner after surgery to pre vent blood clots. Most patients will take Aspirin 81mg Twice daily, until 6 weeks post op.
Usually you will be in hospital for 1-3 days for a revision surgery 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 for 14 days, then a cane for an additional 1-2 weeks.
Your staples will be removed in the office at approximately 2 weeks after surgery.
Bending your knee is variable, but by 2 weeks it should easily bend to 90 degrees. The goal is to get 110-120 degrees of movement.
You will be allowed to shower after the surgical drain is removed and covered. The incision will be completely covered with a waterproof bandage, called an Aquacel. We do not want this bandage removed at all until you return to the office for your first post-operative visit at 1 week after surgery.
You can drive at about 3-4 weeks after surgery. This will vary for each patient and depends which leg was operated on. Usually once you have regained full control of your leg, you are not using a walker or talking pain medication you should be safe to drive. 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 1 week, 2 week, and approximately a 4-6 week check-up with your surgeon who will assess your progress. You should continue to see your surgeon, every 3-5 years for the lifetime of your joint replacement 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.
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
Infection can occur with any operation. In the hip this can be superficial or deep. Infection rates are approximately 1%. If it occurs it can be treated with antibiotics but may require further surgery. Very rarely your hip may need to be removed to eradicate infection.
Blood Clots (Deep Venous Thrombosis)
These can form in the calf muscles and can travel to the lung (Pulmonary embolism). These can occasionally be serious and even life threatening. If you get calf pain or shortness of breath at any stage, you should notify your surgeon.
Fractures or Breaks in the Bone
Can occur during surgery or afterwards if you fall. To repair these, you may require surgery.
Stiffness in the knee
Ideally your knee should bend beyond 100 degrees but on occasion the knee may not bend as well as expected. Sometimes manipulations are required, this means going to the operating room where the knee is bent for you under anesthetic the knee.
The plastic liner eventually wears out over time. Most joint replacements should last 15-20 years.
Wound Irritation or Breakdown
Surgery will always cut some skin nerves, so you will inevitably have some numbness around the wound. This does not affect the function of your joint. You can also get some aching around the scar. Vitamin E cream and massaging can help reduce this.
Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely further surgery.
The knee may look different than it was because it is put into the correct alignment to allow proper function.
Leg length inequality
This is also due to the fact that a corrected knee is more straight and is unavoidable.
An extremely rare condition where the ends of the knee joint lose contact with each other or the plastic insert can lose contact with the tibia (shinbone) or the femur (thigh bone).
The Patella (knee cap) can dislocate. This means it moves out of place and it can break or loosen.
There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or break or stretch out any time afterwards. Surgery may be required to correct this problem.
Damage to nerves and Blood Vessels
Rarely these can be damaged at the time of surgery. If recognized they are repaired but a second operation may be required. Nerve damage can cause a loss of feeling or movement below the knee and can be permanent.
Discuss your concerns thoroughly with your Orthopaedic Surgeon prior to surgery.
Surgery is not a pleasant prospect for anyone, but for some people with arthritis, it could mean the difference between leading a normal life or putting up with a debilitating condition. Surgery can be regarded as part of your treatment plan it may help to restore function to your damaged joints as well as relieve pain.
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.