Partial Knee Replacement
A partial/ unicompartmental knee replacement is a minimally invasive surgery in which only the damaged compartment of the knee is replaced with an implant. It is also called a partial knee replacement.
The knee can be divided into three compartments: patellofemoral, the compartment in front of the knee between the knee cap and thigh bone, medial compartment, on the inside portion of the knee, and lateral compartment which is the area on the outside portion of the knee joint.
Not all patients are suitable for this procedure. Partial knee replacement is a surgical option if your arthritis is confined to a single compartment of your knee.
Various types of arthritis may affect the knee joint. Osteoarthritis is the most common degenerative joint disease that affects mostly middle-aged and older adults, and it may cause the breakdown of joint cartilage and adjacent bone in the knees. They are other causes of severe knee arthritis.
- Rheumatoid arthritis
The main goal of a partial knee replacement is to restore function to the damaged knee and to relieve pain that cannot be controlled by other treatments.
How is the procedure for a Partial Knee Replacement / Unicompartmental knee replacement performed?
- The surgery is performed under spinal or general anaesthesia.
- Your surgeon will make an incision in the skin over the affected knee to expose the knee joint. The incision will be smaller than the standard total knee replacement operation.
- Then the damaged portions of the femur bone are cut at appropriate angles using specialized jigs with the help of computerised navigation
- The femoral component is attached to the end of the femur with or without bone cement. The surgeon then cuts or shaves the damaged area of the tibia (shinbone) and the cartilage. This removes the deformed part of the bone and any bony growths, as well as creates a smooth surface on which the implants can be attached.
- Next, the tibial component is secured to the end of the bone with or without bone cement. Your surgeon will place a plastic piece called an articular surface between the implants to provide a smooth gliding surface for movement. This plastic insert will support the body’s weight and allow the femur to move over the tibia, like the original meniscus cartilage.
- The femur and the tibia with the new components are then put together to form the new knee joint. To make sure the patella (knee cap) glides smoothly over the new artificial knee, its rear surface is also prepared to receive a plastic component. With all the new components in place, the knee joint is tested through its range of motion. The entire joint is then irrigated and cleaned with a sterile solution.
- Lastly, the incision is carefully closed and a sterile dressing is placed over the incision.
How long does take to recover from the Operations?
You should be able to stop using your crutches or walking frame and resume normal leisure activities 4-6 weeks after surgery. Generally, speaking this operation allows for earlier weight-bearing and return to normal function compared to the total knee replacement operation, However, it may take up to 2-3 months for pain and swelling to settle down. It can take up to a year for any leg swelling to disappear.
The advantages of Unicompartmental / Partial Knee Replacement over Total Knee Replacement include:
- Smaller incision
- Less blood loss
- Quick recovery
- Less post-operative pain
- The better overall range of motion
- Feels more like a natural knee
What is the average Hospital Stay?
The average hospital stay after total knee replacement is three days and most patients spend several more days in an inpatient rehabilitation facility.
Patients who prefer not to have inpatient rehabilitation may spend an extra day or two in the hospital before discharge to home.
What to avoid after a knee replacement?
Exercising benefits your health and aids your recovery after surgery.
It is the best to be cautious with the activities listed below after knee replacement:
- Running and jogging
These activities stress your knee and can cause pain. If running is your passion, discuss with the doctor and physiotherapist. You can set a goal but start by walking.
- Weight training
Heavy lifting especially during squats and similar exercises, puts pressure on your joints. The physiotherapist may have safer suggestions or techniques for your new knee.
- High-impact sports or aerobics
Sports like football and basketball combine the danger of running with the risk of hitting other players and damaging your knee.
Hiking can be low impact, but trails with uneven ground and erupting roots or rocks can cause falls. Stick to even paths or trails if possible.
- Skateboarding and rollerblading
These activities carry a significant risk of twisted knees and falls on concrete which would lengthen your recovery process.