What is Revision Knee Replacement?
A well-done knee replacement usually lasts for 20 to 25 years. During this period the knee gradually wears out and in the end will need another surgery. This surgery is called revision knee replacement in which the worn-out knee is replaced with a new knee.

What are the Causes of Early Failure in Knee Replacement?
In rare cases, if there was a technical problem with the initial surgery then the knee may fail early requiring early revision knee replacement. However, with the usage of computers for knee replacement such errors in techniques can be avoided giving each knee the best result.

Is Infection a Cause for Early Revision? How to Prevent it?
Yes, Infection is a very rare complication in knee replacement but can occur in less than 1% of patients. There are various ways to prevent and avoid infection which is as follows.

• 1. A well-equipped operation theatre which has laminar flow with HEPA air filter
• 2. Use of Space suite to avoid the spread of infection
• 3. Use of disposable items wherever possible
• 4. Use of antibiotics as per the norms.
• 5. Proper control of diabetes before surgery

What is the Treatment for Infected Total Knee Replacement?
We do two staged procedure for infected knee, which is followed by a most surgeon. In the first stage, we remove the infected knee and fill it with an antibiotic cement spacer. The patient will be on higher antibiotics for a minimum period of 3 months. We wait for 6 months to one year for the infection to settle. Meanwhile, patient can walk and do routine activities including knee bending. After six months to one year we do a set of blood tests to confirm that there is no residual infection and then as a second stage we remove the cement spacer and put the new knee.

What are the Treatments Available for a Failed Total Knee Replacement because of Causes Other than Infection?
As mentioned earlier, technical problems which can lead to early failure of knee replacement are

1. Ligament imbalance

2. Incorrect positioning of the knee

3. Incorrect alignment of the lower limb

4. Mismatch of the gaps

5. Leaving the knee-cap bone without resurfacing

6. Fracture after knee replacement

7. Other technical causes

Treatment depends on the cause of the failure. Usually, the surgery would include one or more of the following.

1. Insert exchange

2. Leg bone component revision

3. Thigh bone component revision

4. Knee cap resurfacing

5. Total revision

A case of knee replacement done elsewhere came to us with knee instability. She was managed with a revision knee replacement where we just exchanged the insert without replacing the thigh or leg bone component. The patient was absolutely fine after revision surgery and is leading a normal life.