A total knee replacement is an effective way of improving symptoms of knee arthritis.

Also known as a total knee arthroplasty, this surgery involves replacing the knee joint with a prosthetic device that carries out similar functions as a person’s own knee.

Knee replacement surgery has become a routine procedure in many hospitals. Surgeons carry out approximately 600,000 total knee replacements annually in the United States.

According to the American Academy of Orthopedic Surgeons (AAOS), 90 percent of people who have a knee replacement experience a significant reduction in pain.

For many, it helps them to stay active and may enable them to return to activities they previously enjoyed, such as walking and golf.

The AAOS notes that over 90 percent of replacement knees are still functioning after 15 years. According to research published in 2019, 82 percent of total knee replacements are still functioning after 25 years.

For most people, a successful knee replacement typically leads to a higher quality of life, less pain, and better mobility.

After a year, many report significant improvements in:

  • pain
  • stiffness
  • physical function
  • vitality
  • social functioning

The authors of one study noted that a total knee replacement “offers profound improvements of physical activity for the majority of patients.”

Knee replacement surgery is relatively safe and effective for most people. According to the AAOS, fewer than 2 percent of people experience severe complications, such as an infection or a blood clot.

Infection

In 1981, one expert estimated that the infection rate for knee surgery was 9.1 percent. Newer practices of giving antibiotics before and during the operation have reduced the risk dramatically to around 1 to 2 percent.

Risk factors for infection include diabetes, obesity, and older age.

Blood clots and DVT

Blood clots can develop after surgery. These are called deep vein thromboses (DVTs). If a DVT breaks off and travels to the lungs, it results in a pulmonary embolism (PE), which can be life threatening.

One study found that 1.2 percent of people were hospitalized with blood clots within 90 days of total knee replacement surgery. Of these, 0.9 percent had DVT and 0.3 percent had PE, a more serious condition.

Osteolysis

Osteolysis (destruction of bone) happens when microscopic plastic particles from the knee implant cause inflammation. Loosening of the knee joint can occur over time.

According to research, osteolysis is the most common reason for long-term failure of a total knee replacement, requiring a second (revision) operation.

Stiffness

Stiffness, or arthrofibrosis, is one of the more common complications after knee replacement surgery. It occurs when scar tissue forms in the knee and limits movement of the new joint.

The best way to avoid stiffness is to follow the exercise regimen that your healthcare providers recommend.

Pain

Pain usually reduces as a result of knee surgery. Statistics vary, but according to one estimate, 20 percent of people may continue to experience persistent pain despite a well-performed operation.

Revision

Revision is when a person needs a second knee replacement at some point in time after their initial operation.

Experts estimate that 5 percent of people will need a revision within the first 10 years. Of these, 29.8 percent are due to the joint coming loose, 14.8 percent due to infection, and 9.5 percent due to pain.

If a person has a high risk of complications, the surgeon will discuss this with them during the evaluation process. In some rare cases, a surgeon may not recommend surgery because the potential risks outweigh the benefits.

Studies show that after knee replacement surgery most people experience an improvement in their:

  • quality of life
  • activity levels
  • mobility

However, most won’t be as mobile and active as people who have never had knee problems.

Knee replacement is relatively safe, but there are risks. Knowing the risks and discussing them with your doctor can help you make your decision about whether knee surgery is right for you.

Did you know?

More than 90 percent of total knee replacements still work after 15 years.

Healthline