Partial Knee Replacement

What is a Partial Knee Replacement?

Partial knee replacement simply means that only a part of the knee joint is replaced through a smaller incision than would normally be used for a total knee replacement.

Partial Knee Replacement Surgical Procedure

Each knee is unique and knee replacements take this into account by having different sizes for your knee. If there is more than the usual amount of bone loss, sometimes extra pieces of metal or bone are added.

Surgery is performed under sterile conditions in the operating room under spinal or general anaesthesia. You will be on your back and a tourniquet applied to your upper thigh to reduce blood loss. Surgery will take approximately two hours.

The patient is positioned on the operating table and the leg prepped and draped. A tourniquet is applied to the upper thigh and the leg is prepared for the surgery with a sterilising solution. An incision around 7 cm is made to expose the knee joint. Smaller incisions are made if the surgery is done using arthroscopy. The bone ends of the femur and tibia are prepared using a saw or a burr. Trial components are then inserted to make sure they fit properly. The real components (Femoral & Tibial) are then put into place with or without cement. The knee is then carefully closed and drains usually inserted, and the knee dressed and bandaged.

Post-operation Care after Partial Knee Replacement

Usually, you will remain in the hospital for 3-5 days. Depending on your needs, you will then return home or proceed to a rehabilitation facility. You will need physical therapy on your knee following surgery. You will be discharged on a walker or crutches and usually progress to a cane at six weeks. Bending your knee is variable, but by 6 weeks it should bend to 90 degrees. The goal is to obtain 110-115 degrees of movement. Once the wound is healed, you may shower. You can drive after about 6 weeks, once you have regained control of your leg. You should be walking reasonably comfortably by 6 weeks. More physical activities, such as sports previously discussed, may take 3 months to be able to perform comfortably.

When you go home you need to take special precautions around the house to make sure it is safe. You may need rails in your bathroom or modify your sleeping arrangements especially if you are sleeping upstairs.

You will usually have a 6 week check up with your surgeon, who will assess your progress. You should continue to see your surgeon for the rest of your life to check your knee and take X-rays. This is important as sometimes your knee can feel excellent, but there can be a problem only recognised on X-ray.
If you have any unexplained pain, swelling, or redness or if you feel generally poor, you should see your doctor as soon as possible.

Risks and Complications of Partial Knee Replacement

As with any major surgery, there are potential risks involved and may include:

• Surgical site infection
• Blood clots (Deep Venous Thrombosis)
• Fractures or breaks in the bone
• Stiffness in the knee
• Wear and tear of implants
• Wound irritation or breakdown
• Cosmetic appearance
• Leg length inequality
• Dislocation
• Patella problems
• Ligament injuries
• Damage to nerves and blood vessels

Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery.

Advantages of Partial Knee Replacement

• Smaller operation
• Smaller incision
• Not as much bone removed
• Shorter hospital stay
• Shorter recovery period
• Blood transfusion rarely required
• Better movement in the knee
• Feels more like a normal knee
• Less need for physiotherapy
• Able to be more active than after a total knee replacement