Revision Knee Replacement

INTRODUCTION

This booklet has been compiled by Melbourne Hip and Knee to help you better prepare you for Revision Knee Replacement surgery, and to provide guidelines for post-operative recovery, care and rehabilitation. The long term goal of Revision Knee Replacement surgery is to provide pain relief, return you to normal daily activities and ensure you have an enhanced quality of life.

What is revision knee replacement?

The vast majority of knee replacement surgery is successful. Rarely, the replacement comes loose, wears out, gets infected, becomes unstable, or even breaks. When this happens, it may need to be removed and a new replacement put in. This is called a revision knee replacement. Occasionally, a partial knee replacement will need revision not because the replacement is a problem, but because the parts of the knee that hadn’t been replaced are now worn out.

How do I know if my knee replacement needs to be revised?

Pain is the commonest symptom of a knee replacement that needs revision. It may be a sign that the knee is loose or infected. Other symptoms include instability of the knee or patella (knee cap), stiffness, and pain or deformity from a fracture of the bone around the replacement.

If you haven’t noticed any of these problems, then it is very unlikely that your knee replacement needs to be revised.Revision Knee Replacement surgery is more challenging than a standard knee replacement, often with increased risks. The recovery is typically slower also. For these reasons, the decision to perform revision surgery is not taken lightly. Your surgeon at MHK will discuss these factors with you.

How is a revision knee replacement performed?

Revision knee replacement surgery is performed under general or spinal anaesthesia. During the procedure, your surgeon will make an incision at the front of the knee to expose the knee joint. The old metal components and plastic insert are carefully removed from the femur and tibia.

After removal, the bone ends are prepared to accept the new implants. Sometimes areas of bone loss may need grafting or the use of an implant to fill the gap.

The new components are secured in place to form the new knee joint. The incision is closed.

Managing an infected knee replacement (1-stage vs. 2-stage)

If infection is the diagnosis, then a decision will be made whether to manage the revision replacement as a 1-stage or 2-stage procedure. 1-stage means removal of the current implants, thoroughly cleaning the bone and joint, and then replacing the joint. 2-stage means temporarily placing an antibiotic spacer to help cure the infection, then coming back at a later date and safely implanting the new joint replacement.

How effective is revision knee replacement?

The most important factor in whether revision knee replacement is successful is having the correct diagnosis ie. being sure what theproblem is beforehand.

For example, approximately 90% of chronic infections will be cured, though it is often a two-stage process. The common problems in revision knee replacement are stiffness and weakness. This develops when the first replacement is failing, before the revisionsurgery.It is possible to revise a knee replacement 2, 3 or more times if necessary, but each time the knee maybe a bit weaker and stiffer. Every revision is different, and it is important to discuss your particular problemwith your surgeon.

How effective is revision knee replacement?

A Total Knee Replacement (TKR) or Total Knee Arthroplasty is a surgery that replaces an arthritic knee joint with artificial metal or plastic replacement parts called the ‘prostheses'.

Knee replacement surgery typically takes between one and two hours to complete. Surgery is performed under sterile conditions in the operating room under spinal or general anaesthetic (you will be asleep). You will be on your back and a tourniquet applied to your upper thigh to reduce blood loss.

In the knee replacement procedure, each prosthesis is made up of four parts.

The tibial component has two elements and replaces the top of the shin bone or tibia. This prosthesis is made up of a metal tray attached directly to the bone and a high density plastic spacer that provides the bearing surface.

The femoral component replaces the bottom of the thigh bone or femur. This component also replaces the groove where the patella or kneecap rides.

The patellar component replaces the surface of the knee cap, which rubs against the femur. The patella protects the joint, and the resurfaced patellar button will slide smoothly onto the front of the joint. In some cases, the patella is not resurfaced.

If you have any further questions, please ask your surgeon.