Revision Knee Replacement

• Introduction
• Why does a knee replacement needs to be revised?
• Pre-operation
• Day of your surgery
• Surgical procedure
• Post-operation course
• Risks and complications
• Summary

Find out more about Revision Knee Replacement with the following link

Introduction

Revision Knee Replacement means that part or all of your previous knee replacement needs to be re-done. 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).

Why does a knee replacement needs to be revised?

There are many reasons for revision. Knees without an obvious cause for pain in general do not do as well after surgery.

Isolated 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’ when you walk.

Loosening of either the femoral, tibial or patella component – This usually presents as pain but may be asymptomatic. Xrays usually demonstrate significant loosening. A bone scan may be required

Infection- usually presents as pain but may present as swelling or an acute fever.

Osteolysis (bone loss). This can occur due to polyethylene plastic 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 situation.

Pre-Operation

• Your surgeon may send you for routine blood tests
• Investigations required prior to your surgery
• You will be asked to undertake a general medical check-up with your GP to ensure that you are fit for a big operation
• 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
• Stop aspirin or anti-inflammatory medications 10 days prior to surgery as they can cause bleeding
• Stop taking any naturopathic or herbal medications 10 days before surgery
• Stop smoking as long as possible prior to surgery

Day of Surgery

• You will be admitted to the hospital, usually on the day of your 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 prior to surgery
• The operation site will be shaved and cleaned in the operating theatre
• Approximately 30 minutes prior to surgery, you will be transferred to the operating theatre

Surgical Procedure

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 theatre 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 between one-three hours.

The Patient is positioned on the operating table and the leg prepped and draped.

An incision around 10cm is made to expose the knee joint.

The old components are carefully removed to ensure that no further damage is done to the remaining joint.

The bone ends of the femur and tibia are prepared using a saw or a burr.

Trial components are then sized/ inserted to make sure they fit properly. Stems and wedges are used if required

The revision components (Femoral & Tibial) are then put into place with or without cement.

The knee is then carefully closed and drains may be inserted, and the knee dressed and bandaged.

Post-operation Course

When you wake up, you will be in the recovery room with intravenous drips in your arm, possibly a tube (catheter) in your bladder and a number of other monitors to check your vital observations. You will usually have a button to press for pain medication through a machine called PCA machine (Patient Controlled Analgesia).

Once stable, you will be taken to the ward. The post-op protocol is surgeon dependant, 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 24 hrs of surgery. The dressing will be removed usually on the 2nd post-op day to make movement easier. Your rehabilitation and mobilization will be supervised by a physiotherapist.

To avoid lung congestion, it is important to breathe deeply and cough up any phlegm you may have.

Your knee surgeon will use one or more measures to minimize blood clots in you legs, such as inflatable leg coverings, stockings and injections into your abdomen to thin the blood to avoid clots or DVT’s, which will be discussed in detail in the complications section.

A lot of the long term results of knee replacements and revision replacement 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 stick at six weeks.

Your sutures are sometimes dissolvable but, if not, are removed at approximately 12-14 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. If you have an automatic car, you may be able to drive earlier. You should be walking reasonably comfortably by 6 weeks.

More strenuous physical activities may take 3 months to be able to do comfortably.

When you go home you need to take special precautions around the home to make sure it is safe. You may need rails in your bathroom or to modify your sleeping arrangements especially if they are up 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

• As with any major surgery, there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages
• 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
• Blood loss requiring transfusion with its low risk of disease transmission
• Heart attacks, strokes, kidney failure, pneumonia, bladder infections
• Complications from nerve blocks such as infection, bleeding or nerve damage
• Serious medical problems can lead to ongoing health concerns, prolonged hospitalization or rarely death

Local complications

Infection

Infection can occur with any operation. In the knee 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 knee may need multiple operations 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 address 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 theatre where the knee is bent for you under anesthetic. This may need to be combined with an arthroscopic arthrolysis (keyhole surgery to excise scar tissue).

Wear

The plastic liner may eventually wear out over time, usually 10 to 15 years and may lead to the need for revision.

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 may help reduce this.

Occasionally, you can get reactions to the sutures or a wound breakdown that may require antibiotics or rarely further surgery.

Cosmetic Appearance

The knee may look to be a slightly different shape and will have a scar

Leg length inequality

This is also due to the fact that a corrected knee is straight and may be unavoidable.

Dislocation

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).

Patella Problems

The Patella (knee cap) can dislocate. This means it moves out of place and it can break or loosen.

Ligament Injuries

There are a number of ligaments surrounding the knee. These ligaments can be torn during surgery or stretch out and break 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 surgeon at ‘The Cambridge Knee’ prior to surgery.

Summary

Surgery is not a pleasant prospect for anyone, but for some people with arthritis or a failed knee replacement , 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 and it may help to restore function to your damaged joint, 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, your family and your general 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.