Correction of a Loose Knee Replacement

What is a Knee Replacement?

Knee replacement is a surgery employed to resurface a knee joint damaged by arthritis, wear and tear, or injury and replacing the damaged joint with a prosthesis (an artificial knee joint) to resolve a painful knee condition and loss of motion.

What is Correction of a Loose Knee Replacement?

Reoperation of a total knee replacement to correct a loosened prosthesis as a result of wear and tear of the prosthetic joint surfaces is known as correction of a loose knee replacement. This procedure involves a complete or partial exchange of prostheses implanted during the original total knee replacement with new prostheses.

Knee Anatomy

The knee is made up of the femur (thighbone), the tibia (shinbone), and patella (kneecap). The lower end of the thighbone meets the upper end of the shinbone at the knee joint. A small bone called the patella (kneecap) rests on a groove on the front side of the femoral end. A bone of the lower leg (fibula) forms a joint with the shinbone. The bones are held together by protective tissues, ligaments, tendons, and muscles. Synovial fluid within the joint aids in smooth movement of the bones over one another. The meniscus, a soft crescent-shaped cartilage between the femur and tibia, serves as a cushion and helps absorb shock during motion.

What are the Indications for Correction of a Loose Knee Replacement?

Some of the indications that prompt revision knee surgery includes:

• Infection: The metal and plastic implants can be susceptible to bacterial infection causing painful joints.
• Wear and Loosening: The friction caused by rubbing of the joint surfaces against each other wears away the surface of the implant leading to bone loss and loosening of the implants.
• Instability: Improperly placed implant may cause instability leading to a sensation of the knee “giving way” where soft tissue encircling the knee is found to be too weak to aid in standing or walking.
• Fracture: Injury or fractures around the knee implant may disturb the stability requiring revision surgery.
• Stiffness: Knee stiffness can result from improper positioning of the implant, excess scar tissue formation, poor motion before surgery, and other surgical complications.

How Do You Prepare for Correction of a Loose Knee Replacement?

Before surgery, your physician will examine your overall health and assess anaesthesia risks. This evaluation will also include:

• A full physical examination
• A full medical history, including any prior surgeries or ongoing health conditions
• X-rays
• Blood tests
• Other imaging tests

Your physician will ask about any medications or supplements that you may be taking and instruct you on which ones to stop taking prior to the surgery. You will also be asked about any allergic reaction to anaesthesia or medications. Finally, a consolidated report of the above tests and evaluation will be submitted to your surgeon for reference before undertaking the surgery.

Procedure for Correction of a Loose Knee Replacement

The procedure will be performed under general or regional anaesthesia. After adequately sterilizing the surgical area, your surgeon will make a long surgical incision over the knee. The muscles and skin are pulled back and the damaged cartilage and bone are cut and removed. A new artificial knee joint is secured to your femur and tibia using specialized cement, screws, and pins. Your surgeon will then close the incision with sutures or staples and cover with sterile dressings.

Postoperative Care

Post surgery, you will feel some stiffness and pain in your leg. You will receive pain medications to help manage the pain. You will receive blood-thinning medication such as heparin to prevent blood clots. Most people are able to start physical therapy in a day or two of the surgery to boost blood flow to the tissues around the knee. Your surgeon may recommend using a special brace-like device known as continuous passive motion machine that aids in moving your knee in a gentle bending fashion. You will be instructed on surgical site care and a specific physical therapy regimen to strengthen the muscles and improve range of motion. Finally, based on your condition and the results of your surgery, your surgeon will recommend discharge from the hospital.

What are the Benefits of Correction of a Loose Knee Replacement?

More than 90 per cent of individuals who have undergone revision knee surgery have noticed significant improvement in their well-being, including:

• Increased mobility
• Reduced pain
• Improved joint function
• Improved quality of life
• High satisfaction and success rate

What are the Risks and Complications Involved with Correction of a Loose Knee Replacement?

As with any surgery, some of the potential complications involved with corrective surgery for failed knee replacement include:

• Bleeding
• Infection
• Intraoperative fractures
• Damage to blood vessels and nerves
• Blood clots or deep venous thrombosis
• Pulmonary embolism
• Stiffness or instability of the joint
• Anaesthetic complications