Five-year implant survival does not differ between hybrid and cementless total knee arthroplasty.
This article is based on the peer-reviewed study “Five-Year Implant Survival Does Not Differ Between Hybrid and Cementless Total Knee Arthroplasty in a Cohort of 5,361 Patients Using a Deep-Dish Mobile Bearing Design” by Manchec O et al., published in Knee Surgery, Sports Traumatology, Arthroscopy (2025).
Professor Etienne Cavaignac, co-author of the paper, summarises here the key insights for patients and surgeons.
Understanding Fixation in Total Knee Arthroplasty
Total Knee Arthroplasty (TKA) is among the most frequently performed orthopaedic operations worldwide, aiming to relieve pain and restore mobility in severe knee arthritis.
One of the main debates in orthopaedic surgery concerns the method of implant fixation, whether components should be cemented, cementless or hybrid (with only one component cemented).
Cementless TKA
In a cementless TKA, the implant is designed to allow bone to grow directly onto its porous surface, creating a biological bond.
Hybrid fixation TKA
In contrast, hybrid fixation combines the two principles, for example, a cemented tibial component for enhanced stability under compression and an uncemented femoral component to encourage bone integration.
Advances in implant design and coatings such as titanium and hydroxyapatite have significantly improved the performance of cementless prostheses, prompting new comparisons with hybrid fixation techniques.
A Large Multicentre Study Comparing 5-Year Outcomes
This research evaluated outcomes in 5,361 patients operated on across 15 French centres using the same deep-dish mobile-bearing TKA design (SCORE I, Amplitude®).
Three fixation strategies were analysed:
- Fully cementless implants (n = 4,549)
- Hybrid with cemented tibia and uncemented femur (n = 435)
- Hybrid with cemented femur and uncemented tibia (n = 377)
Patients were followed for up to five years, with survival analyses performed using advanced statistical models and propensity score matching to account for age, sex, BMI and surgical variables.
The study focused on two main evaluation criteria:
- Primary outcome: the implant’s survival rate without revision, meaning how long the prosthesis remained in place without requiring surgical replacement.
- Secondary outcomes: the overall surgery-free survival rate (including and excluding infections), as well as functional results, measured by the International Knee Society (IKS) score which assesses pain, mobility, and stability and by the range of motion (ROM) of the knee.
Key Results: Similar Survival and Function Across All Groups
The study demonstrated that five-year implant survivorship was equivalent between hybrid and cementless total knee arthroplasties, regardless of which component was cemented.
- Cementless TKA: 98.7 % survival (95 % CI 98.2–99.1)
- Hybrid Tibial: 97.8 % (94.6–99.1) – p = 0.537
- Hybrid Femoral: 98.4 % (94.9–99.5) – p = 0.669
No statistical difference was found in revision-free survival, surgery-free survival or aseptic re-operation rates.
The most common cause of revision was infection, not mechanical loosening.
Functional outcomes also improved comparably:
- Average IKS score at 5 years ≈ 180 points (+80 vs pre-op).
- Average knee flexion ≈ 115–120°.
After adjustment for preoperative values and patient characteristics, no clinically significant difference remained between the three fixation methods.
Clinical Significance for Surgeons and Patients
Implant durability
The equivalence of results suggests that modern cementless fixation is as reliable as hybrid techniques in the medium term.
Surgeons may therefore choose fixation based on bone quality, intra-operative findings, or personal preference without compromising implant longevity.
Biomechanical considerations
Because tibial bone is mainly subjected to compressive and shear forces, some surgeons prefer tibial cementation to reduce micromotion, while keeping the femoral side cementless to promote bone ingrowth.
This study confirms that such partial cementation does not provide measurable survival benefits at five years.
Functional outcomes
The comparable gains in motion and IKS score reinforce the idea that fixation type has limited influence on recovery and function, provided that implant alignment and soft-tissue balance are optimal.
Modern implant design matters
Earlier generations of cementless components were associated with higher loosening rates.
However, second-generation porous coatings and mobile-bearing designs now ensure excellent biological fixation and improved load distribution, explaining the robust results observed.
Methodological Strengths and Limitations
This was one of the largest multicentre cohorts on the topic, with over 5,000 TKAs analysed and uniform implant design, a factor that reduces variability.
Rigorous multivariate and propensity-score analyses enhanced statistical reliability.
However, the authors acknowledge some limitations:
- Median follow-up = 27 months (5-year data available for 1,505 patients).
- Non-randomised design → possible residual bias (e.g., surgeon preference).
- Loss to follow-up ≈ 28 %, limiting long-term interpretation.
Despite these constraints, findings align with previous randomised controlled trials and meta-analyses confirming the excellent mid-term performance of cementless and hybrid TKAs.
Conclusion: Cementless or Hybrid Are Both Reliable at 5 Years
This study concludes that hybrid fixation provides no additional benefit over cementless fixation in mid-term outcomes for total knee arthroplasty.
Implant survival, reoperation rates, and patient-reported outcomes were equally high, demonstrating the reliability of both methods when performed with modern designs and techniques.
For patients, this means that whether their surgeon recommends a cementless or hybrid prosthesis, they can expect excellent stability and function at five years.
To explore more of Professor Cavaignac’s research on knee replacement and robotic-assisted surgery discover his other scientific publications.
For expert advice on choosing the most suitable type of knee implant and fixation method, consult Professor Etienne Cavaignac, orthopaedic surgeon and specialist in knee arthroplasty, Toulouse University Hospital.