When the decision for revision knee replacement is made, standard assessments are performed, including x-rays, laboratory tests, and possibly other imaging modalities like bone scans, CT scans, X-rays may demonstrate a change in the position or condition of the components. Magnetic resonance Imaging (MRI) helps to determine the cause, location, and the amount of bone loss before surgery. Aspiration of the knee (joint fluid removed with a needle) may be required if infection is suspected. This aspirated fluid will then be sent to a laboratory for analysis to identify the specific type of infection.

What happens during revision knee replacement surgery?

Most revision total knee replacements take longer to perform than primary procedures (about two to three hours). The first step is removal of the implant. If there has been significant bone loss, bone grafts may be required to fill the voids. Bone grafts can be either auto graft (patient’s own bone taken from another site of patient’s body) or an allograft (bone tissue from another person obtained from a bone bank). In some cases, metal wedges, wires or screws may be used to strengthen the bone. Finally, specialized revision knee implants are inserted. Temporary drains are usually placed to collect any fluids or blood that may remain after surgery

What about after revision knee replacement surgery?

Post-operative care after knee revision surgery is very similar to the care of a primary knee replacement. This includes a combination of physical therapy, blood management, and pain medication as necessary. Antibiotics and some method of blood clot prevention will be continued in the postoperative period. A brace or splint may be used to protect the joint after the surgery.

Recovery time after revision knee surgery varies; some patients take longer to recover. In most cases, physical therapy will be initiated within 24 hours of the procedure. In some cases, protective weight bearing, such as Partial Weight Bearing (PWB) or Toe Touch Weight Bearing (TTWB), is needed to promote bone healing. Therapy will usually continue for up to three months following the surgery. Assistive devices, such as a walker or crutches, will be used early in the convalescence period, and patients will progress to a cane or walking without any assistance as their condition improves.

What are the risks and complications?

Complications that may follow knee revision surgery are similar to those for knee replacement. They include:

• Deep vein thrombosis.
• Infection in the new implant
• Implant loosening. Overweight patients are at higher risk.
• Dislocation of the new implant. The risk of dislocation is twice as high for revision surgery as for a primary knee replacement.
• Additional or more rapid loss of bone tissue.
• Bone fractures during the operation that could occur if the surgeon must use force or pressure to remove the old implant.
• Difference in leg length resulting from shortening of the leg with the new prosthesis.
• Formation of Heterotopic bone, which is bone that develops at the lower end of the femur following surgery. Joint infections after surgery put patients at increased risk.
• Prior medical conditions, such as heart and lung complications, or stroke conditions, can be aggravated by a revision procedure. These conditions may also develop in patients after revision surgery. Very rarely, death can occur.