Healthy Living

Reasons for Knee Replacement Surgery

Reasons for Knee Replacement Surgery

Knee replacement surgery is a surgical procedure that involves the removal of parts of your natural knee joint and replacing them with artificial parts known as prostheses. Knee replacement is a very common procedure used to repair your knee joint.

Many conditions can make your doctor decide to perform a knee replacement, but arthritis is the most common reason. Other factors that can lead to the need for a knee replacement include obesity, repetitive injuries, genetics, and abnormalities in bone development.


The knee joint is the body's largest, most complex, and most stressed joint. Its complexity and the stress it weathers every day can cause arthritis. Knee surgery, whether partial or total knee replacement, can be an effective treatment for degenerative arthritis present in the knee joint.

Types of Arthritis

The types of arthritis that can lead to knee replacement surgery include:

  • Osteoarthritis - This is arthritis that occurs when the cartilage found on the gliding surface of the knee starts to wear out causing stiffness and pain. Once the cartilage wears out completely, the bones begin to rub directly against each other, causing chronic pain and reduced mobility. Osteoarthritis is a common condition in people over fifty years of age. It is also common in people with a family history of arthritis and those who perform activities that stress the knee joints such as laborers and athletes.
  • Rheumatoid arthritis - This is an autoimmune disorder that comes about when the body's immune system starts to fight or attack its own synovial membrane, making it inflamed and produce excess synovial fluid. The whole process results in wearing out and damage to the articular cartilage.
  • Traumatic arthritis - This is a type of arthritis that results after serious injury to the knee such as ligament damage or bone fracture. The impact of the injury can cause a mini-trauma for the articular cartilage that with time develops to osteoarthritis.

Apart from arthritis, knee replacement surgery can be performed if your knee joint has:

Avascular Necrosis (AVN)

This is a condition that can lead to knee bone degeneration. The proper medical name for avascular necrosis is osteochondritis juvenalis or osteochondritis dessicans. This condition is mostly seen in young adults and adolescents. The condition occurs in portions of the articular surface, mainly on the femoral condyles. The bones around the knee become soft, losing cohesion to the extent where large and small fragments can separate and form loose bodies around the knee joint.  Large fragments can cause instability, joint locking, and a lot of pain. Some medications can be used to treat the condition, but the condition become worse as the patient matures.

Abnormal Alignment

The abnormal formation or alignment of the knee can lead to high stress on the joint causing degeneration. Abnormal alignment is also known as being knock-kneed, where the femur and tibia are at an unusual angle, causing irregular stress on the knee joint. After a long period of joint usage, the cartilage wears away unevenly.

When is knee replacement necessary?

Knee replacement surgery is a major procedure that is usually recommended when other type of treatments for arthritis such as steroid injection and physiotherapy have failed to improve joint mobility and reduce pain.

A knee replacement surgery will be performed if:

  • You can’t have a normal social life.
  • You can’t do any work.
  • You are stressed and depressed due to lack of mobility and pain.
  • Daily chores such as bathing and cooking become a problem.
  • When the knee is so painful that it interferes with sleep and your quality of life.
  • You have swelling, stiffness, and pain in your knee and movement becomes a problem.

Types of Knee Replacement Surgery

Partial knee replacement (PKR) surgery

In this type of surgery, only one side of your knee is replaced with a prosthesis. This is a smaller operation generally performed when only one side of your knee is damaged. During the procedure, a small cut is made and a small bone is removed. The removed bone is then replaced with a prosthesis. This replacement is suitable as a first-round method for people who have osteoarthritis. The procedure involves a shorter hospital stay and less blood transfusion.

Total knee replacement surgery

Total knee replacement is a procedure that involves replacing all the knee parts with artificial ones. It aims to relieve knee pain and restore the function of an arthritic knee. The major reason for having a total knee replacement is to treat the knee pain associated with arthritis when all other treatments such as medicines, weight loss, physical therapy, and injections have failed. A total knee replacement successfully cures pain and improves one’s quality of life since it is aimed at improving and maintaining the knee's function.

This surgery can be performed on patients of all ages except children whose bones are still growing. One should have a disability or significant pain before a surgeon considers total knee replacement.

Are there alternative treatments for my knee?

Apart from knee replacement, there are other procedures that can be used to treat arthritis of the knee. They include:

  • Kneecap replacement - This can be performed only for a damaged kneecap. It is fast and simple procedure with fast recovery time.
  • Mini-incision surgery - This is a new surgical technique commonly used in partial knee replacement. It is different from PKR since the surgeon makes a small cut rather than a large opening in the front part of the knee.
  • Image-guided surgery - This is considered a procedure that is very accurate in the positioning of your knee. The surgeon is guided by infrared beacons and computerized images.
  • Osteotomy - This is an open operation where the knee bone is cut and then aligned anew so that it can bear one's body weight.
  • Arthroscopic washout - In this procedure, an arthroscope is inserted in the knee through a small incision. The whole knee is washed with saline water that clears away any tiny bones.
  • Autologous chondrocyte implantation (ACAI) - This is a procedure where new cartilage from the patient's own body is manufactured artificially in a test tube and then later introduced into the damaged knee.

Bottom Line

Above all other conditions, arthritis is the major reason why one would need knee replacement surgery. Other factors that can lead to the need for a knee replacement include obesity, repetitive injuries, genetics, and abnormalities in bone development.