In the overwhelming majority of cases, replacement surgery is a safe procedure. However, there are potential complications associated with this or any surgery. All patients undergoing joint replacement need to understand the potential risks. I read that there are 700,000 knees replaced and 500,000 hips replaced every year.
Let's look at a couple of potential problems.
Blood Clots (DVT)
Due to the nature of this type of procedure, lood clots in the larger veins of the leg and pelvis (deep venous thrombosis, or DVT) are more common after joint replacement surgery than, say, arthroscopy which I'm certain some of the readers have had. To minimize the risk of developing these blood clots, you will start you will be placed on some kind of blood thinning regimen that, in some cases, will continue for several weeks following the operation. Compression stockings are frequently worn to keep the blood in the legs circulating. Early mobilization, getting up and out of bed, physical therapy, etc. all contribute to the prevention 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 doctor 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 serious complication. It can even necessitate removal of the joint replacement implant. Infections sometime 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 an early infection. However, some infections require removal of the implants, followed by weeks of IV antibiotics. To reduce the risk of an infection once you have a joint replacement, you may be told to take antibiotics for dental work, colonoscopies and the like are performed.
When surgery is performed, you 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. Occasionally, physical therapy must be continued for months following the surgery.
Failure or Loosening
Over time, implants wear out and may loosen. New technology has helped this problem, but wearing out of implants and loosening still occurs. 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. Obesity also contributes to early failure.
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 physicians often delay joint replacement surgery as long as possible, especially in younger patients.
Hip DislocationDislocation 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 doctor 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.
Note: Almost 20% of patients who undergo total knee replacement find that it doesn't live up to their expectations. this is especially true in those with mild to moderate osteoarthritis. Perhaps the expectation level was too high? A replaced knee is not equal to "original equipment.
Next time we'll go into post op activity choices, swim - bike -run and how the athlete and his/her doc make this an individual decision.