Knee replacement surgery: what you need to know

A knee replacement removes damaged bone and cartilage and replaces them with a metal, ceramic, or acrylic prosthesis to restore functionality in the knee. In this article, a consultant orthopaedic explains the reasons and process of a knee replacement surgery.

Understanding the knees

The knee is the body’s largest joint, at the junction of the thigh bone (femur) and the tibia (shin bone), and topped by the kneecap (patella). Surrounding it are an assortment of muscles, ligaments, and cartilage (such as the meniscus).
The knees are a fundamental structure for human movement. They enable walking, sitting, crouching, dancing, jumping, cycling… knees are used constantly in daily life. They support a lot of the body’s weight, and help maintain balance. So, when something goes awry, it can be quite debilitating.

Knee replacement is major surgery, so it is considered the last option for people who are suffering from extreme and chronic knee pain, who are immobile due to knee issues, or who have had an accident that has resulted in the sudden and complete destruction of the knee.

What are the reasons for knee replacement surgery?

The main reasons a knee might need replacement are:

• Arthritis, which is when the joint becomes inflamed due to a deterioration or infection of the cartilage. Common kinds of arthritis are osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis.
• Fractures, which can happen during accidents, strenuous activities, or even just mundane daily tasks.
• Wear-and-tear, which is what happens when the knee has been overused and the joint has become strained. This can happen to those who do a lot of physical activities, like athletes, dancers, or people who are on their hands and knees often.

Patients of knee replacements tend to be between 60 – 80 years old. They can last for 20 years, so it is unlikely that a patient will need more than one replacement in their lifetime, but it is better to get one later rather than sooner so that it will last longer.

What does knee replacement surgery consist of?

There are two kinds of knee replacement surgery:

• Total, which is the majority of knee replacement surgeries, and involves the lower end of the femur and the upper end of the tibia being removed and replaced with metal or plastic.
• Partial, which is used for cases where the damage, such as arthritis, is only on one part of the knee that is then replaced.

A knee replacement is performed with a local or general anaesthetic and takes around two hours. The procedure starts with the surgeon making an incision down the front of the knee and moving the kneecap away so that the joint can be accessed. The damaged bone is sawn off and shaped so that the new replacement can be fitted on top. The kneecap is then put back into place and the incision is sealed and dressed.

What happens after a knee replacement?

Recovery from knee replacement can take several months, perhaps up to a year, but this varies based on the kind of knee replacement and the condition of the patient. After the surgery, the patient will be prescribed painkillers. A patient will likely spend a couple of nights in the hospital to adjust and for monitoring before returning home. Patients will need to undergo physiotherapy in order to learn how to use the new knee and strengthen the muscles.

If you are considering a knee replacement, consult with a specialist today via Top Doctors.