At Palmetto Bone and Joint, our priority is helping patients return to active, pain-free lives through safe and effective surgical care. One of the most common procedures we perform is total knee replacement (also called total knee arthroplasty), a surgery that can dramatically improve mobility and quality of life for individuals suffering from advanced osteoarthritis, rheumatoid arthritis, or other degenerative joint conditions.

While advancements in surgical technique and implant technology continue to evolve, not all innovations necessarily lead to better long-term outcomes. One recent trend that has emerged in the field of knee replacement is the increased use of press-fit or uncemented total knee implants. These implants are designed to rely on the patient’s bone growing into the implant surface to achieve fixation, rather than using bone cement for immediate stability.

While press-fit designs are well-established in hip replacements and have shown excellent long-term performance in that context, evidence suggests that press-fit total knee implants have not yet demonstrated the same level of success as their cemented counterparts. In fact, recent registry data and clinical studies indicate a higher rate of complications, particularly aseptic loosening and the need for revision surgery, in press-fit knee replacements when compared to cemented implants.

This article will explore what this means for patients considering knee replacement surgery, and why it’s important to discuss implant choices and long-term outcomes with your surgeon.

What Is the Difference Between Cemented and Press-Fit Knee Replacements?

In a cemented total knee replacement, a special medical-grade bone cement (usually polymethylmethacrylate or PMMA) is used to anchor the metal and plastic components of the knee prosthesis securely to the prepared surfaces of the femur and tibia. This technique has been the gold standard for decades, with proven long-term durability and reliability.

In contrast, a press-fit or uncemented implant has a porous or specially coated surface designed to encourage the patient’s natural bone to grow into and around the implant over time. This biologic fixation aims to create a strong, lasting bond between the implant and the bone without the use of cement.

While this approach has shown great success in hip replacements—particularly in younger patients—it has not yet been widely adopted or validated in the knee joint, where the anatomy, loading forces, and movement patterns are significantly different.

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What the Research Says: Press-Fit Knees Have Higher Failure Rates

Numerous studies and national joint replacement registries have reported higher rates of aseptic loosening (a form of implant failure that occurs without infection) in press-fit knee replacements compared to cemented ones.

Key Findings:

• A 2021 study published in The Journal of Arthroplasty analyzing over 12,000 total knee replacements found that uncemented implants had a higher risk of early revision—especially within the first 5 years after surgery.

• Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) consistently show higher revision rates for uncemented knees. Their 2022 report notes that the cumulative revision rate for uncemented knees was significantly higher than for cemented knees at nearly all time points.

• The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man has also demonstrated higher failure rates with press-fit knees, prompting many high-volume centers to remain cautious about their widespread adoption.

The most common cause of failure in press-fit knees is aseptic loosening of the tibial component, where the bond between the bone and implant fails before bone in-growth can fully occur, leading to pain, instability, and the need for revision surgery.

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Why This Matters for Patients

Revision surgery is more complex, carries higher risks, and often results in a longer recovery period and less optimal function compared to a primary (first-time) knee replacement. The primary goal of any joint replacement is to maximize longevity and minimize the likelihood of additional surgeries—particularly important for younger, more active patients.

While some surgeons may advocate for press-fit designs in certain younger patients with good bone quality, the reality is that cemented knees have a far more predictable track record, with many lasting 20 years or more when performed properly and followed by a healthy recovery and rehab process.

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Questions You Should Ask Your Surgeon Before Knee Replacement

If you’re considering knee replacement surgery, it’s essential to be an informed patient. We strongly encourage you to ask your orthopedic surgeon the following questions:

1. What type of implant do you plan to use—cemented or press-fit? Why?

   • Ask your surgeon to explain their reasoning and whether it is based on your specific anatomy, age, or bone quality.

2. What is the expected longevity of the implant you’re recommending?

   • Cemented knees have well-documented longevity in clinical studies. Be cautious if long-term data is lacking for the implant being proposed.

3. What is your personal revision rate or the revision rate of the implant you use?

   • Surgeons who track their outcomes will often have this information readily available.

4. Do national or international registries support the use of this implant?

   • Reputable joint registries provide real-world data that can help guide evidence-based decisions.

5. What happens if the implant loosens or fails?

   • Understanding the implications of revision surgery can help you make a more informed choice.

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Our Approach at Palmetto Bone and Joint

At Palmetto Bone and Joint, our surgical team prioritizes proven techniques and implants that have demonstrated consistent long-term success. We perform hundreds of total knee replacements each year, and we stay up to date with the latest research, registry data, and implant technologies to ensure our patients receive the best possible outcomes.

In the vast majority of our total knee replacements, we continue to use cemented fixation, which has shown superior reliability and longevity across a wide range of patients. We take a personalized approach to each case, considering your age, activity level, bone quality, and overall health before recommending a surgical plan.

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Final Thoughts

Knee replacement surgery can be life-changing, but it’s not a decision to be taken lightly. As a patient, you deserve full transparency and the opportunity to make informed choices about the implants and techniques being used in your body.

Don’t be afraid to ask questions. If your surgeon is recommending a press-fit knee, ask them to provide evidence to support that decision, and consider seeking a second opinion if needed.

Ultimately, your goal—and ours—is the same: a successful knee replacement that stands the test of time and allows you to enjoy life without pain or limitation.

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Schedule a Consultation

If you’re considering knee replacement surgery, contact Palmetto Bone and Joint today to schedule a consultation with one of our experienced orthopedic specialists. We’ll walk you through all of your options, answer your questions, and help you make the decision that’s right for your health and your future.