Knee replacement surgery, also known as total knee arthroplasty (TKA), is a procedure to replace damaged joint surfaces in the knee with artificial components. This surgical intervention resurfaces the ends of the thigh bone, shin bone, and often the kneecap with metal and plastic parts. It is typically considered when severe arthritis or injury has significantly damaged the knee, leading to persistent pain and reduced mobility that other treatments cannot address.
Typical Lifespan
Most total knee replacements are designed for long-lasting function. Current data indicates that between 85% and 90% of total knee replacement patients can expect their artificial knee to last 15 to 20 years. Looking further out, studies show that approximately 80% to 85% of these implants remain functional after 20 years. Research suggests over 80% of total knee replacements can last for 25 years or more.
Influences on Durability
Several factors influence how long a knee replacement performs. A patient’s age at the time of surgery plays a role, as younger individuals tend to be more active, which can place greater stress on the implant and potentially lead to earlier wear. Body weight also significantly impacts implant longevity, as excess weight increases the load on the artificial joint, accelerating wear and tear. Activities involving high impact, such as running or jumping, can also contribute to faster wear of the implant materials.
The design and materials of the implant itself are key. Modern prostheses, often made from durable metal alloys and high-grade plastics, are continually improving to minimize wear and enhance longevity. The precision of the surgical technique and proper alignment of the components during the initial procedure are also crucial for the implant’s long-term success. Following surgery, adherence to rehabilitation protocols and avoiding complications like infection or loosening contribute to the implant’s durability.
Signs of Wear and Next Steps
When a knee replacement wears out or fails, signs may indicate a need for medical evaluation. Patients might experience increasing pain, especially during activity or at rest. Other symptoms can include swelling, stiffness, or a feeling of instability in the knee. Individuals may also notice grinding or clicking sounds, or a decreased range of motion.
These symptoms suggest a potential problem with the implant, such as loosening of the components or wear of the plastic parts. If these issues arise, the next step is a medical assessment, which may include imaging tests to determine the extent of the problem. When an implant fails, a procedure known as revision surgery is often necessary to remove and replace some or all of the original components. Revision surgery is generally more complex than the initial knee replacement and requires specialized planning.
Maximizing Implant Longevity
Patients can take steps to extend the life of their knee replacement. Maintaining a healthy weight is recommended, as it reduces the stress and load placed on the artificial joint. Engaging in low-impact exercises such as walking, swimming, cycling, and yoga can help maintain joint flexibility and muscle strength without overstressing the implant. High-impact activities like running or jumping should generally be avoided to protect the joint.
Adhering to post-operative instructions, including consistent participation in physical therapy, is also essential for recovery and long-term joint health. Regular follow-up appointments with the orthopedic surgeon allow monitoring the implant’s condition and addressing issues early. Promptly reporting new or worsening symptoms to a healthcare provider ensures timely intervention and can prevent significant problems.