03 Oct

Knee Replacement Surgery

By

Knee replacement surgery (also called knee arthoplasty) can repair knee joints damaged by arthritis. This popular procedure has been in use since 1968 and has undergone many improvements over the years.

Orthopedic Surgeons typically use the knee replacement procedure only in cases where nonsurgical treatments are no longer beneficial for the patient. Options that a doctor may try before going the surgical route include medications such as steroids along with physiotherapy and the use of canes or walkers.

Why Knee Replacement is Necessary

The knee joint consists of the lower end of the femur, the top of the tibia and the patella. Smooth cartilage covers the point where these bones meet. The degradation of this cartilage means that the surfaces the bones to grind against each other causing pain and limiting the joint's flexion. Conditions that cause cartilage breakdown include:

  • Osteoarthritis
    Osteoarthritis is a problem faced mostly by older adults. The disease causes the degradation of cartilage in the knee joints. People with osteoarthritis may have severe pain when walking, climbing stairs or standing up from a seated position. 
  • Rheumatoid Arthritis
    This disease causes the thickening and inflammation of the synovial membrane. The synovial membrane surrounds the knee joint and when it becomes inflamed, it can cause damage to cartilage resulting in the same symptoms as osteoarthritis. 
  • Knee Trauma Arthritis
    This type of arthritis is the result of a serious accident where bones are broken and ligaments are torn. Trauma alone is unlikely to damage joint surfaces; however, torn ligaments can eventually cause damage to knee cartilage. This damage occurs because the ligaments are no longer holding the knee in the correct position. 
 

Types of Knee Replacement

  • Total Knee Replacement
    This procedure involves the replacement of both sides of the joint. 
  • Partial Knee Replacement
    In a partial knee replacement, the surgeon replaces one side of the joint.
 

The Knee Replacement Procedure

In most cases, knee replacement surgery takes place with the patient under general anesthesia.

 

During the procedure, the surgeon will resurface the bones in your knee joint. Knee replacement surgery takes place in four stages:

  • Bone Preparation
    The bone is prepared with the removal of the damaged cartilage on the femur and tibia. 
  • Cartilage Replacement
    The surgeon replaces the cartilage with metal that is either cemented or press-fit onto the joint surfaces. 
  • Patella Resurfacing
    This step involves resurfacing the underside of the kneecap. Because the patella does not always need resurfacing, the surgeon assesses the need for this step on a case-by-case basis. 
  • Spacer Insertion
    A plastic spacer is positioned between the metal surfaces to help them slide against each other smoothly.

After the Surgery

It is essential that you begin a physical therapy program as soon as possible after surgery. This often starts with the use of a continuous passive motion (CPM) machine, which flexes and extends the knee while you are still in bed. This helps to prevent stiffness and the buildup of scar tissue. After your discharge, you will continue physical therapy until you regain muscle strength and the full range of motion. 

What to Expect After Knee Replacement Surgery

It is important to be realistic about the results of your knee replacement surgery. You can expect:

  • To have your pain lessened considerably. Most people who have the procedure performed report a significant reduction in pain.
  • To see improved knee flexion along with the ability to perform basic tasks that you were previously unable to perform due to arthritis.

You should not expect:

  • Improved abilities beyond what they were before the onset of arthritis.
  • A permanent solution. Obesity or high impact activities can shorten the lifespan of knee components. Even without these things, the components can still wear out over time.
 

Most patients are able to start walking without aids within six weeks of their knee replacement surgery and are able to resume driving within 12 weeks.

 

Knee replacement is an effective solution for knee arthritis that can help you to resume basic activities without pain. If you are dealing with severe knee pain from arthritis, ask your doctor whether knee replacement surgery is right for you.