Remember when taking the stairs, running after the bus or sinking into a comfy couch were no big deal? You weren’t thinking about how much work your knees were doing. But now that you’re dealing with chronic pain, the stress on your knees may be something you think about daily – and a knee replacement may be on your mind.

According to the American Academy of Orthopedic Surgeons, over 790,000 knee replacement surgeries are performed in the United States every year. Knee replacements help improve your mobility, reduce knee pain and get you back to doing the things you love. But as with any medical procedure, it’s important to understand the possible risks of having knee replacement surgery.

The good news is that knee replacement surgery is generally considered a safe procedure. Complications are very rare. In fact, various studies show that over 95% of patients recover from knee replacement surgery without complications.

So, what are the knee replacement risks you need to know? What you can do to reduce them? Below we answer those questions and more.

Possible knee replacement surgery complications


All surgeries require incisions – cuts that allow surgeons to open an area of the body and make repairs. So, this means there’s a chance of infection – but it’s an extremely small chance.

When infections do arise, they’re considered serious. That’s why it’s very important to follow the care instructions given to you by your doctor, including keeping your wound clean and dry, and taking any prescribed antibiotics. And if any increasing redness, swelling or pain happens, you’ll need to contact your doctor right away.

Longer-term knee stiffness

It’s normal to feel a little stiff and swollen for a few months after surgery. This is just your body recovering and adjusting to your new knee or knees. But sometimes that stiffness can last.

Longer-term stiffness is typically caused by excessive scar tissue. Oftentimes, lack of use or exercise can cause scar tissue to build up in the soft tissue around the joint. That’s one of the reasons physical therapy following surgery is recommended. Movement is good for your joints.

By following your doctor’s recommendations about movement and sticking to your physical therapy plan, you can help prevent the buildup of scar tissue and stiffness. But if you do experience longer-term stiffness, your doctor may recommend additional treatments such as additional physical therapy or joint manipulation.

Persistent knee pain

Some discomfort immediately after surgery is normal. It’ll take some time for your body to adjust to your knee replacement. Pain typically lessens after two to three months, but you’ll probably notice improvement every week.

However, some people can continue to have persistent knee pain after surgery. When this happens, your doctor will work with you to create a treatment plan, which may include additional physical therapy, cognitive behavioral therapy or medicines to help you feel more comfortable.

Implant failure

Knee implants are built to be long-lasting. But there’s a small chance that the implant will fail. Implant failure is when the replacement joint isn’t able to work properly. Typically, persistent pain and stiffness can be signs of implant failure.

Why do knee implants fail? Infection, instability or stiffness are considered the most common causes of implant failure. Others causes can include an issue with the implant itself, like a fracture, and aseptic loosening. Aseptic loosening is a condition when the bond holding the implant in place comes unstuck from wear and tear.

So, how long do knee replacements last?

Unfortunately, no knee replacement lasts forever. Because we use our knees whenever we walk, sit or do other activities, the replacement knees will eventually wear out.

Many patients have knee replacements that last 20 years or longer. Timing your knee replacement surgery correctly can help you get the most benefit from the artificial joint.

Will I need to have a second knee surgery?

If you experience implant failure, you’ll likely need a second surgery to replace it. But generally speaking, most people won’t need a second knee replacement surgery. In fact, a recent study showed that the 10-year implant survival rate is more than 96 percent. In addition, the 20-year survival rate was roughly 90 percent.

Several factors can play a role in the longevity of a knee replacement. People who are overweight, do heavy manual work or play vigorous sports are at a higher risk of needing a second knee surgery. And complications, like implant failure, may increase your risk of needing a revision to your knee replacement.

Nerve or blood vessel damage

During surgery, there’s a slight chance that the nerves, veins or tissue around your knee can be damaged. Damaged nerves or blood vessels can cause numbness, pain or lower blood flow around the knee. Usually, any damage will heal on its own over time. In some cases, a procedure may be recommended to help fix the issue.

Blood clots

Because a knee replacement affects the way blood flows around your knee, it can increase your risk of developing blood clots. In rare cases, blood clots can cause serious complications including a pulmonary embolism (a blood clot in your lungs).

To reduce your risk of blood clots, your doctor may prescribe blood thinning medications. But the most important thing you can do to reduce your risk of developing blood clots is to move around after surgery. This includes walking around your room, walking to and from the bathroom, keeping up with your physical therapy exercises and other movements throughout the day.

How to minimize your risk of complications from knee replacement surgery

Each person’s individual risk of developing complications after knee replacement surgery is different. But there are some steps you can take to help your knee replacement go smoothly and reduce the likelihood you’ll develop a complication.

Make preparing for knee surgery a priority

Taking certain steps to prepare for knee replacement surgery and the recovery process is important. This can help reduce stress in the lead up to the surgery and set you up for a successful recovery.

For example, one prep step should be making adjustments to your home to make it more safe and comfortable for life after surgery. This can include clearing clutter, rearranging furniture to create larger walkways and adding safety rails to your bathroom.

Follow your recovery plan

Your surgeon will give you detailed instructions to follow after your surgery, and it’s important to stick to that plan as closely as possible. Your recovery plan can include things like:

  • Wound care instructions
  • In-clinic physical therapy sessions
  • At-home exercises
  • Medical pain management
  • And more

Take it easy

Using your new knee and getting back to your routine is an important part of recovery. But throwing yourself back into your usual activities too quickly can make your pain worse.

Be patient with yourself as you recover and don’t be afraid to ask for help. Asking family and friends to offer support can also help you stick closely to your recovery. Arrange help with rides, errands and other necessary activities so you don’t push yourself too hard, too fast.

Choose an expert surgeon

Choosing an experienced surgeon can reduce your risk of complications. You should look for a surgeon who has performed hundreds of successful surgeries.

At TRIA, our orthopedic surgeons are considered among the best in the Midwest. One year after surgery, 97 percent of our knee replacement patients reported that they can walk down stairs with little to no difficulty.

More questions about knee replacement risks? Talk with an orthopedist.

Choosing to have knee replacement surgery is a big decision. And the truth is, there may be other non-surgical treatment options that can help heal your knee pain.

Whether you’re wondering about individual knee replacement risks or want a second opinion, don’t delay getting the care and answers you need. Make an appointment with an orthopedic doctor and take the first step toward healing your knee pain.