Risks of Hip and Knee Replacement

Hip replacement surgery and knee replacement surgery are performed for the treatment of severe arthritis. During these procedures, the arthritic joint is removed and replaced with an artificial implant. Prior to joint replacement surgery, you should have a very thoughtful discussion with your healthcare provider and have your questions answered. You should understand the potential risks of joint replacement surgery.

Joint replacement surgery is a safe procedure. However, there are potential complications associated with this surgery. All patients undergoing joint replacement need to understand the potential risks of joint replacement surgery.

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Blood Clots

Blood clots in the large veins of the leg and pelvis (deep venous thrombosis, or DVT) are common after joint replacement surgery. To minimize the risk of developing blood clots, your healthcare provider will start you on blood-thinning medication that will continue for several weeks following your joint replacement. In addition, you will be given compression stockings to keep the blood in the legs circulating. Early mobilization with therapy after the surgery will also help prevent blood clot formation.

The concern is that if a blood clot develops, it is possible that the clot can travel to the lungs (called a pulmonary embolism), which can be potentially fatal. If your healthcare provider finds evidence of blood clot formation, you will likely be given a higher dose of blood-thinning medication for a longer period of time.


Infection of a joint replacement is a very serious complication and may necessitate the removal of the joint replacement implant. Infections sometimes occur in the days and weeks following surgery (early infection) or years down the road (late infection). An attempt to surgically clear the infection and leave the implants in place is sometimes made, especially in the setting of early infection. However, some infections require removal of the implants, followed by weeks of IV antibiotics. To reduce the risk of infection once you have a joint replacement, you may be told to take antibiotics when invasive procedures (such as dental work or colonoscopies) are performed.


When surgery is performed, your body's natural response is to make scar tissue. This is true both on the skin and deep down inside the joint. Because scars contract, a tightening of the soft tissues around your joints can occur. If this occurs after a knee or hip replacement procedure, you may have difficulty bending your knee, sitting in a chair, or walking up and down stairs. Because of this, it is important to begin activity as soon as possible after surgery. Aggressive physical therapy must be continued for months following the surgery. If stiffness persists despite physical therapy, manipulation under anesthesia may be performed. This breaks up scar tissue, but it will require you to again be aggressive with physical therapy.

Implant Loosening or Failure

Over time, implants wear out and may loosen. New technology has helped this problem, but wearing out of implants and loosening still occur. Most hip and knee replacements last an average of about 20 years. Some last less than 10, some more than 30, but every implant eventually wears out. This is more of a problem in younger patients, who live longer and typically place more demands on the implanted joint.

If the joint wears out, a revision replacement (replacement of a replacement) may be performed. This is a more complicated surgery, and the lifespan of the implant decreases with each revision surgery. This is one reason why healthcare providers often delay joint replacement surgery as long as possible, especially in younger patients.

Hip Dislocation

Dislocation of a hip replacement occurs when the ball dislodges from the socket. This can occur for many reasons but often occurs after a fall or in patients with problems such as Parkinson's disease. Hip dislocation can even occur with simple activities such as while sitting down on a low seat. For this reason, you may be instructed to follow hip precautions. These precautions include:

  • Not crossing your legs
  • Using elevated seats
  • Not bending your hip up more than 90 degrees (toward your chest)
  • Sleeping with a pillow between your legs
  • Avoiding turning your foot inward

Is Joint Replacement Too Risky?

These are some of the common complications following surgery, though this is by no means comprehensive. Before undergoing this surgery you should have a long discussion with your healthcare provider and ask all your questions. You may be referred to an internist to have a full medical evaluation before surgery and discuss any medical issues that may be unique for you.

Joint replacement surgery is outstanding — the results have been excellent, and the outcome of most patients is wonderful. However, there are risks to this surgery, and it is important to understand these before you proceed.

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By Jonathan Cluett, MD
Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams.