Total Knee Replacement
Why is a Knee Replacement Performed?
The most common reason to have a knee joint replaced is to relieve pain from severe arthritis that is limiting your activities.
You may be recommended a knee replacement for these problems:
- You can’t sleep through the night because of knee pain
- Your knee pain has not improved with other treatments (e.g. painkillers, physiotherapy)
- Your walking distance is severely limited
- Your knee pain limits or prevents you from doing your normal activities, such as bathing, preparing meals, doing household chores, and walking.
The Oxford Knee Score is a very valuable guide to the severity of your symptoms, it can also be used to measure success after the operation.
The Aim of Surgery
- A successful knee replacement will achieve the following;
- Relief of pain
- Increased level of activity (walking, leisure activities)
- Good range of movement allowing full extension and a good amount of bending in the knee (0-115 degrees)
- Last a long period of time (no early loosening requiring revision surgery)
- No other complications (e.g. infection, nerve injury)
The knee joint acts as a hinge between the bones of the leg and is effectively two joints. The major joint is between the thigh bone of the upper leg (femur) and the shin bone of the lower leg (tibia). The smaller joint is between the knee cap (patella) and the upper leg (femur). A smooth, tough tissue called articular cartilage covers the ends of the bones, allowing them to slide smoothly over each other. The synovial membrane that covers the other surfaces of the knee joint produces synovial fluid, which lubricates the joint, reducing friction. If the articular cartilage becomes damaged or worn, the ends of the bones rub or grind together, causing pain and difficulty moving the knee joint.
Replacing the damaged knee joint with an artificial one can help reduce pain and increase mobility.
Total knee replacement comprises resurfacing the bones of the tibia, femur and patella with a metal implant and then placing a high-grade plastic spacer to create a gliding surface.
What Happens after the operation?
You will be in hospital for approximately 3 days after the operation. You will walk on the first day after the operation with crutches, and need them for 6 weeks.
Physiotherapy is used to regain muscle strength and range of movement.
Are there any risks?
The major risks following a knee replacement are:
- Infection – 1%
- Deep Vein Thrombosis (DVT) – 2%
- Loosening – Implants last 10-15 years