Wellness Blog

In Total Knee Replacement surgery (also called Total Knee Arthroplasty), the Orthopaedic Surgeon will resurface your damaged knee with artificial components, called implants.

There are many different types of implants.

The metal-on-plastic combination is the most commonly used material for knee implants.

The brand and design used by your doctor or hospital depend on many factors. These include the patient's knee problem, age, weight, activity level, patients' demands and overall health.

Implant Components:

Implants are made of metal alloys, cobalt chrome material, and strong plastic parts. Up to three bone surfaces may be replaced in a Total Knee replacement.

1. The lower end of the femur. The metallic femoral component curves around the end of the femur (thighbone). It is grooved so the kneecap can move up and down smoothly against the bone as the knee bends and straightens
2. The top surface of the tibia (shinbone). The tibial component is typically a flat metal platform with a cushion of strong, durable plastic, called polyethylene. Some designs do not have the metal portion, and instead, the polyethylene attaches directly to the bone. For additional stability, the metal portion of the component may have a stem that inserts into the centre of the tibia bone.
3. The back surface of the patella. The patellar component is a dome-shaped piece of polyethylene that duplicates the shape of the patella (kneecap). In some cases, the patella need not be resurfaced.

Components are designed so that metal always interfaces with plastic, which provides for smoother movement and results in less wear of the implant.

There are different ways to fix knee implants to the bone.

1. Cemented fixation. Implants are held in place with a fast-curing bone cement (polymethylmethacrylate).
2. Cementless fixation. Implants can also be press-fit onto bone. This type of fixation relies on new bone growing into the surface of the implant. Cementless implants are made of a material that attracts new bone growth. Most are textured or coated so that the new bone grows into the surface of the implant.
3. Hybrid fixation. In hybrid fixation for total knee replacement, a combination of cemented and cementless fixation is used.

Implants label or sticker: The implant labels/stickers serve as a crucial record of the specific implant used in a procedure, ensuring accurate identification and traceability. The bathing Femoral Component label from the box of the components of the implant is stuck on a page in your hospital chart and in the discharge summary. The label or sticker would contain the necessary Information. It contains

1. Implant Details: Model, serial number, batch number, and potentially the manufacturer's name.
2. Invoice: A copy of the invoice may be included to document the cost of the implant for 3-P insurance claims