Key Takeaways

  • Knee replacement failure is uncommon, with most implants lasting 15-20 years or more.
  • The primary causes of failure include infection, mechanical loosening, implant wear and tear, and instability.
  • Warning signs include persistent pain, new swelling, a feeling of instability, or reduced range of motion.
  • If failure is suspected, treatment options range from nonsurgical management to revision knee replacement surgery.

Is Knee Replacement Failure Common? A Look at the Success Rate

If you are living with a knee replacement or considering one, the question “can a knee replacement fail?” is a natural and important one. The thought of undergoing such a significant procedure only to have it fail can be a source of anxiety. We want to start by offering reassurance: knee replacement surgery is one of the most successful procedures in modern medicine. The vast majority of implants function beautifully for 15 to 20 years, and often much longer, allowing patients to reclaim an active, pain-free life.

Procedures like a total knee replacement or even a partial knee replacement are designed for durability and longevity. The goal of this surgery, also known as arthroplasty, is to alleviate the debilitating pain often caused by arthritis. For more information, you can review our guide to understanding knee arthroplasty and other common knee conditions and care.

While failure is not common, it is possible. Understanding the potential causes and warning signs empowers you to be an active partner in your health. Proper long-term care after knee arthroplasty is key to maximizing the lifespan of your implant. Think of this information not as a reason to worry, but as a guide to help you protect your investment in your mobility and well-being.

Top 5 Causes of Knee Replacement Failure

When a knee replacement does fail, it is typically due to specific, identifiable reasons. Being aware of these potential issues can help you and your orthopaedic specialist catch problems early. Here are the five most common causes of knee implant failure.

Infection (Aseptic vs. Septic)

Infection is one of the most serious complications. It can occur shortly after surgery (acute) or months to years later (chronic). A septic failure is caused by bacteria creating a biofilm on the implant, which can lead to pain, swelling, and drainage. Aseptic failure refers to problems not caused by infection, which we will cover next.

Aseptic Loosening (Implant becomes detached from the bone)

This is the most common reason for late-term knee replacement failure. Aseptic loosening occurs when the bond between the implant and the bone weakens over time. The body’s natural response to microscopic debris from the implant can cause inflammation that dissolves bone around the prosthesis, making it loose, painful, and unstable.

Wear and Tear (Breakdown of plastic components over time)

Modern knee implants are incredibly durable, but they are not indestructible. The artificial joint consists of metal and plastic components. Over many years and millions of steps, the polyethylene (plastic) spacer between the metal parts can begin to wear down. This wear can lead to pain, instability, and the release of debris that contributes to aseptic loosening.

Instability (Feeling of the knee giving way)

A successful knee replacement relies on a delicate balance of the surrounding soft tissues, including ligaments and tendons. If these structures are not properly balanced during the initial surgery, or if they become stretched or damaged later on, the knee can feel unstable, as if it might “give out.” This can make walking difficult and increase the risk of falls.

Stiffness (Arthrofibrosis or scar tissue formation)

While some stiffness is normal during the initial recovery, a small percentage of patients develop arthrofibrosis, which is the excessive formation of scar tissue within the joint. This can severely limit the knee’s range of motion, making it difficult to bend or straighten the leg fully.

Warning Signs: How to Know if Your Knee Replacement is Failing

Your body will often provide signals if something is wrong with your knee implant. It is crucial to listen to these signs and not dismiss them, especially if they appear or worsen long after your initial recovery period. Here are key warning signs that warrant an evaluation.

Persistent or Worsening Pain

Pain is the most common symptom of a failing knee replacement. While some discomfort is expected during recovery, pain that continues, returns, or gets worse months or years later is a red flag. This pain might be a dull ache or a sharp, sudden pain, especially during weight-bearing activities. If you previously had arthritis, you may find it helpful to read our frequently asked questions about knee arthritis to differentiate the sensations.

Swelling and Warmth Around the Knee

New or recurrent swelling, especially when accompanied by warmth and redness, can be a sign of infection or a significant inflammatory response. While minor swelling can occur after strenuous activity, persistent inflammation should always be checked by your surgeon.

A Feeling of Instability or “Giving Out”

If you feel that your knee is wobbly, unsupportive, or might buckle unexpectedly, it’s a clear sign of instability. This symptom suggests that the implant may have loosened or that the supporting ligaments are no longer providing adequate stability.

Reduced Range of Motion

A noticeable decrease in your ability to bend or straighten your knee can indicate a problem. This could be due to mechanical issues with the implant, component wear, or the formation of restrictive scar tissue.

A Clicking or Grinding Noise

While some minor clicking can be normal with an artificial joint, a new, loud, or painful clicking, grinding, or popping sound (crepitus) can signal that the implant components are wearing out or loosening.

Diagnosing a Failed Knee Replacement: Our Approach in NY & CT

If you are experiencing any of the warning signs, the first step is a thorough and compassionate evaluation. Here at Plancher Orthopaedics, led by Dr. Kevin Plancher, our diagnostic process is designed to get to the root of the problem with precision and care. We treat every patient like family, ensuring your concerns are heard and fully investigated at both our New York office and our Connecticut office.

Your evaluation will typically include:

  • Detailed Patient History: We will discuss your symptoms, when they began, and how they impact your daily life.
  • Physical Examination: Dr. Plancher will assess your knee’s stability, range of motion, strength, and alignment, and check for any signs of swelling or warmth.
  • Imaging Studies: X-rays are crucial for evaluating the position and fixation of the implant and can often reveal signs of loosening or wear. Sometimes, more advanced imaging like a CT scan or MRI may be needed.
  • Laboratory Tests: If an infection is suspected, blood tests can identify markers of inflammation. We may also perform a joint aspiration, where a small sample of fluid is drawn from the knee joint and sent to a lab for analysis.

This comprehensive approach ensures we have a clear and accurate picture of what is happening inside your knee, allowing us to recommend the most effective path forward.

What Are My Options? Treating Knee Implant Failure

Discovering that your knee replacement is not performing as expected can be disheartening. It is important to remember that effective solutions are available. The right path forward depends entirely on the specific cause of the issue.

For less severe problems like stiffness or minor instability, we may explore nonsurgical avenues first. These often include targeted physical therapy to rebuild surrounding muscle strength, bracing for added support, or modifying your daily activities to reduce joint stress.

However, significant mechanical issues such as loosening, severe wear, or deep infection typically require a surgical solution to ensure long-term relief. The primary treatment in these cases is revision knee replacement surgery. In this procedure, we remove the original implant and replace it with a specialized prosthesis designed to restore stability and function. While this is more complex than your initial surgery, it is a highly effective way to eliminate pain and help you return to an active life.

Get a Clear Diagnosis and a Path Forward

Persistent pain, swelling, or instability after a knee replacement are not symptoms you should ignore. These could be signs of underlying mechanical failure or infection that require expert attention to prevent further damage.

If you are concerned about the longevity of your implant or are experiencing new symptoms, Dr. Plancher and our team are here to provide the answers you need. Schedule an appointment at our New York or Connecticut office today for a comprehensive evaluation and a personalized plan to get you back on your feet.

FAQs

Can knee replacement surgery fail?

Answer: Yes, but failure is uncommon. Most knee replacements function well for many years.

What causes knee replacement failure?

Answer: Common causes include infection, implant loosening, wear, instability, stiffness, or injury.

How do I know if my knee replacement is failing?

Answer: Persistent pain, swelling, instability, reduced mobility, or new symptoms should be evaluated by a specialist.

How common is knee replacement failure?

Answer: The majority of knee replacements last 15 to 20 years or longer without failure.

What happens if a knee replacement fails?

Answer: Treatment depends on the cause and may include nonsurgical care or revision knee replacement surgery.