If you are living with chronic knee pain, advanced arthritis, and mobility issues, undergoing knee replacement surgery can be a life-changing step. Knee replacement is one of the most common and safest procedures, with more than 700,000 done every year in the U.S.
When you are considering knee arthroplasty, an orthopedic surgeon will discuss options, like the knee replacement material and how the implant is secured to your natural bone. Understanding the choices and which will be best for you can help you feel more prepared for and comfortable with the procedure.
Traditionally, orthopedic surgeons have relied on bone cement to hold joint implants in place. However, recent technological breakthroughs have made cementless knee replacement a highly effective and increasingly popular option for the right candidates.
What Are Replacement Knees Made Of?
Modern knee implants are sophisticated medical devices engineered from highly durable, biocompatible materials designed to mimic the natural movement of your joint. An artificial knee implant consists of three primary parts:
- Femoral. The femoral component caps the end of your femur, or thigh bone.
- Tibial. The tibial component caps the top of the tibia, or shin bone.
- Patellar. The patellar component replaces the patella, or kneecap.
The components of an artificial knee are made from different materials. Metal-on-plastic is the most common, but other options include metal-on-metal and ceramic-on-plastic. The plastic is cross-linked polyethylene, providing a smooth surface. The metal is a titanium or cobalt-chromium alloy.
Cemented and Cementless Fixation
In addition to materials, surgeons must choose how to affix the implant to the bones. Cement is the more traditional fixation method, but many surgeons now use cementless fixation.
Cemented Knee Replacement
In a cemented procedure, the surgeon uses specialized medical-grade bone cement to securely anchor the implant to the prepared bone surface. It acts as a grout, filling the microscopic spaces between the artificial implant and the natural bone surfaces.
This technique has been used successfully for decades because it provides immediate implant stability and has an outstanding long-term track record. Cemented fixation has decades of clinical data backing its success. It remains an excellent choice for a wide demographic of patients, particularly older adults or individuals with compromised bone quality.
On the other hand, over time, the repetitive stress of daily activities can cause the thin layer of bone cement to degrade, fatigue, or crack. If the cement interface breaks down, the implant can become loose, resulting in pain and eventually necessitating a secondary revision surgery.
Cementless Knee Replacement
A cementless knee replacement uses a different fixation approach. Instead of relying on bone cement, the implant features a specially engineered porous surface that encourages your natural bone to grow into it over time.
As Dr. Phillip Bostian, one of our knee replacement specialists, explains: “On the back side of the implant … instead of this being cemented to the bone, this has an on-growth surface where the bone actually grows onto the implant itself.”
During the procedure, the surgeon cuts and shapes the bone with extreme precision so the implant fits incredibly snugly against it. Over the weeks following surgery, your natural bone tissue undergoes osseointegration, literally growing into the pores of the metal.
The primary benefit of a cementless approach is that it creates a lasting bond between the implant and the bone. No cement can wear down over time. While the plastic spacer could experience minor wear over decades, Dr. Bostian highlights:
“The plastics that we’re using now are very, very durable, and there’s a very good chance this would be the only operation that a knee would ever need.”
Cemented vs. Uncemented Knee Replacement: A Comparison
| Feature | Cemented Knee Replacement | Cementless Knee Replacement |
| Implant Fixation | Medical bone cement | Bone grows into porous implant surface |
| Initial Stability | Immediate | Immediate press-fit, followed by biological fixation over time |
| Ideal Candidates | Many adults, including those with lower bone density | Often younger, active patients with good bone quality |
| Recovery Considerations | Proven recovery pathway | Similar recovery |
| Long-Term Outlook | Excellent long-term results | Excellent early and mid-term outcomes with promising but unproven long-term results |
Who Is a Good Candidate for Cementless Knee Replacement?
Because cementless fixation relies entirely on your body’s ability to grow new bone into the implant, patient selection is crucial. It is not the ideal path for everyone, which is why a comprehensive evaluation with an orthopedic surgeon is essential.
Cementless knee replacements are best for younger and more active patients. High physical demands place more stress on a joint, making a cementless biological bond highly appealing. Good candidates also have strong, healthy, and dense natural bone tissue that can support the implant and grow into its porous surface over time.
Patients with low bone density, significant bone loss, or severe osteoporosis are typically better candidates for a traditional cemented knee. It provides the reliable, immediate stability required for a safe and successful outcome.
As Dr. Bostian explains in his Advanced Cementless Knee Replacement patient education video, the decision is highly individualized. Rather than one option being universally better, the goal is selecting the fixation method that best matches each patient’s anatomy, bone quality, and long-term goals.
Recovering from Cementless Knee Replacement
Rehabilitation after cementless and cemented knee replacement is generally very similar. Most patients begin walking shortly after surgery and participate in structured physical therapy regardless of the fixation method.
However, while you may be walking right away, the biological bond between the implant and your bone continues to develop over the weeks and months following surgery. You will need four to six weeks to form a true biological bond. This means early recovery requires strict adherence to safety protocols, but the long-term biological stability of a cementless knee replacement offers exceptional durability.
Learn More About Your Knee Replacement Options
Whether a traditional cemented implant or a modern cementless design is right for you depends on your unique anatomy, bone health, and lifestyle.
Our joint replacement specialists stay current with the latest advances in knee replacement technology, including modern cementless implants for appropriate candidates. During your consultation, your surgeon will explain your options, answer your questions, and recommend the approach that offers the most benefits for you.
If you are ready to take the next step and learn more about knee replacement, make an appointment to see an EmergeOrtho-Foothills Region specialist.
Frequently Asked Questions
What Are the Benefits of a Cementless Knee Replacement?
The benefits of cementless fixation include biological fixation over reliance on cement, potential longer-term durability, bone preservation, and the ability to be more active on the joint without wearing down cement.
Is Cementless Always Better Than Cemented?
Neither option is always better than the other. It depends on the individual patient. For example, a patient with significant bone loss or low bone density will benefit more from a cemented fixation.
Is Cementless Knee Replacement Recovery Time Longer?
Total recovery for cementless fixation is similar to that for cemented fixation. The recovery time depends more on individual factors, such as age, health, activity level, and adherence to physical therapy and other recovery protocols.
