If you are considering knee replacement surgery, the type of implant used will affect how your new knee feels, how it moves, and how long it lasts. Yet many patients go into surgery without understanding their knee replacement implant types. This guide explains every option available in the UK in 2026. We compare designs, materials, fixation methods, and what the evidence says about each one.
Going private gives you more say in which implant is used. On the NHS, the surgical team decides. Either way, this guide helps you understand the choices in plain English.
Knee replacement implant types compared – materials, designs, fixation methods, and what to discuss with your surgeon.
A knee replacement implant has three main parts. The femoral component covers the end of your thigh bone. The tibial component sits on the top of your shin bone. Between them is a plastic spacer that acts as the new bearing surface.
There are two broad categories of knee replacement implant types used in the UK today.
A total knee replacement resurfaces all three compartments of the knee joint: the inner (medial), the outer (lateral), and the area under the kneecap (patellofemoral). This is the most common type of knee replacement in the UK. The National Joint Registry records that total knee replacement accounts for approximately 90 per cent of all knee replacements performed.
Total knee replacement suits patients whose arthritis affects most or all of the knee joint. It is the standard procedure for the majority of over-50s with severe osteoarthritis.
A partial knee replacement resurfaces only the damaged compartment of the knee, leaving the healthy bone and ligaments untouched. It is also called a unicompartmental knee replacement or UKR.
Partial knee replacement suits patients whose arthritis is confined to one compartment, usually the inner side. Around 10 per cent of knee replacements in the UK are partial.
The advantages include a smaller incision, faster recovery, and a more natural-feeling knee. The disadvantages are a higher revision rate over 15 to 20 years and the possibility that arthritis may develop in the untreated compartments later.
This short video gives you a clear overview of the different knee replacement implant types available in the UK in 2026. You will learn the differences between total and partial replacements, cemented and uncemented fixation, and fixed-bearing versus mobile-bearing designs – plus how your options may differ on the NHS compared with private treatment.
The bearing surface in a knee replacement is the contact point between the metal femoral component and the plastic tibial spacer. The quality and design of this bearing surface affects wear, lifespan, and how the knee moves.
Almost all knee replacements use a metal-on-polyethylene bearing. The femoral component is made from cobalt-chromium alloy. The tibial spacer is made from ultra-high-molecular-weight polyethylene – a tough medical-grade plastic.
Modern highly cross-linked polyethylene is far more durable than earlier versions. It resists wear better and produces fewer particles over time. This is the standard bearing surface used in both NHS and private knee replacement.
Some newer knee replacement implant types use a ceramic or ceramic-coated femoral component with a polyethylene spacer. Ceramic produces less friction and may reduce wear on the plastic.
Ceramic knee implants are less common than ceramic hip implants. They are available at some private hospitals and may suit patients with metal allergies. The long-term registry data for ceramic knee replacements is still building compared with metal-on-polyethylene.
Oxidised zirconium (marketed as Oxinium by Smith+Nephew) is a metal alloy with a ceramic-like surface. It combines the strength of metal with the low friction of ceramic. Studies suggest it produces less polyethylene wear than standard cobalt-chromium.
Oxidised zirconium knee implants are available in both NHS and private settings, though they are not universally offered. Ask your surgeon if this is an option for you.
You may also find our guide to understanding food allergies during allergy awareness week helpful.
Beyond the bearing material, the design of the tibial component also varies. This is one of the key differences between knee replacement implant types.
In a fixed-bearing knee replacement, the polyethylene spacer is locked in place on the tibial tray. It does not move. The knee bends and extends around this fixed surface.
Fixed-bearing is the most commonly used design in the UK. It is reliable, well-studied, and suits the majority of patients. Most NHS knee replacements use a fixed-bearing implant.
In a mobile-bearing knee replacement, the polyethylene spacer can rotate slightly on the tibial tray. This is designed to mimic more natural knee movement and distribute load more evenly.
Mobile-bearing implants require the surrounding ligaments to be in good condition. They are not suitable for all patients. Some surgeons prefer them for younger, more active patients.
Large-scale registry data has not shown a significant difference in revision rates between fixed-bearing and mobile-bearing implants at 10 to 15 years. The choice often comes down to your surgeon’s experience and preference.
How the implant is fixed to your bone is another important decision. There are three fixation methods used for knee replacement implant types in the UK.
The implant is secured using bone cement (polymethylmethacrylate). The cement creates an immediate, strong bond between the implant and bone. You can bear weight on the joint straight after surgery.
Cemented fixation is the UK standard for knee replacement. It has the longest track record and the strongest evidence base. NICE guideline NG157 recommends cemented fixation as the standard for primary knee replacement in most patients. The National Joint Registry shows that cemented knee replacements have lower revision rates than uncemented ones, especially in patients over 55.
The implant has a textured or porous surface that encourages bone to grow into it over time. This biological bond can be very durable, but it takes several weeks to form fully.
Uncemented knee replacement is less common in the UK than cemented. It may be considered for younger patients with strong bone quality. However, current NJR data does not show uncemented knee implants outperforming cemented ones for most age groups.
A hybrid knee replacement uses cement for one component (usually the tibial tray) and press-fit for the other (usually the femoral component). This approach combines the proven stability of cement with the potential longevity of biological fixation.
Hybrid fixation is used by some UK surgeons but is less common than fully cemented knee replacement.
This is the question most patients ask about knee replacement implant types. Modern implants of all types perform well. The differences between designs are often smaller than patients expect.
The National Joint Registry reports that approximately 96 per cent of total knee replacements are still functioning well after 10 years. At 15 years, the figure is around 90 per cent. Partial knee replacements have slightly lower survival rates, at approximately 90 per cent at 10 years.
NICE recommends that any prosthesis used in the NHS should have a 95 per cent chance of lasting at least 10 years.
Several factors influence how long your knee replacement lasts. The implant type is one factor, but not the only one.
Your weight matters. Carrying extra weight puts more stress on the joint and increases wear on the polyethylene spacer. Your activity level plays a role too. High-impact activities such as running increase wear, while swimming and cycling are gentler on the joint.
The skill of your surgeon is critical. Correct alignment and positioning of the knee replacement components during surgery is one of the strongest predictors of long-term success. Higher-volume surgeons tend to achieve better outcomes.
Your bone quality affects fixation. Patients with osteoporosis may do better with cemented implants that do not depend on bone ingrowth.
On the NHS, the surgical team selects the implant based on clinical protocols and hospital trust supply agreements. For most patients, this will be a cemented, fixed-bearing, metal-on-polyethylene total knee replacement. This is the combination with the most evidence behind it.
You may have limited input into the implant choice on the NHS. The surgeon makes the decision based on your age, weight, bone quality, and how much of the knee is affected.
When you choose private knee replacement, you discuss implant options directly with your surgeon. You can ask about specific designs, bearing surfaces, and fixation methods. If you want a partial knee replacement, a mobile-bearing design, or an oxidised zirconium bearing, your surgeon can explain whether it suits your situation.
Private patients also have access to newer implant technologies. Some private hospitals offer patient-specific instrumentation (PSI) or robotic-assisted surgery, which uses 3D imaging to plan the exact positioning of your implant. These technologies are becoming more widely available but are not yet standard on the NHS.
| Implant Type | Typical Patient | Fixation | Pros | Cons |
|---|---|---|---|---|
| Total (fixed-bearing) | Over 55, widespread arthritis | Cemented | Longest track record, NICE recommended, lowest revision rate | Less natural feel than partial |
| Total (mobile-bearing) | Under 65, good ligaments | Cemented or hybrid | More natural movement, even load distribution | Needs good ligament support |
| Partial (unicompartmental) | Single-compartment arthritis | Cemented | Faster recovery, smaller incision, more natural feel | Higher long-term revision rate |
| Ceramic or Oxinium bearing | Metal allergy, younger patients | Cemented or uncemented | Lower friction, reduced wear | Less long-term registry data |
Whether you are on the NHS or paying privately, these questions help you understand your options.
Our guide to physiotherapy after knee replacement covers the full recovery timeline, exercises at each stage, and NHS vs private physio options.
Our guide explains choosing the right knee replacement surgeon, including what credentials to check and which questions to ask at your consultation.
Read our detailed guide to why choose private knee replacement to compare costs, waiting times, and what to expect from the private pathway.
Modern knee replacement implants are designed to last at least 15 to 25 years. Data from the National Joint Registry shows that approximately 96 per cent of knee replacements are still functioning well after 10 years, and around 90 per cent last beyond 20 years. Implant longevity depends on your activity level, weight, and the quality of the original surgery.
A cementless knee replacement uses an implant with a specially textured or coated surface that encourages your natural bone to grow into and bond with the implant over time, rather than using bone cement to fix it in place. It is increasingly popular for younger, more active patients because it may support easier revision surgery in the future if needed.
Yes, the materials affect durability, wear rates, and suitability for your lifestyle. Most implants combine a cobalt-chromium or titanium metal component with a polyethylene (medical-grade plastic) bearing surface. Some use ceramic or oxidised zirconium for reduced wear. If you have a metal allergy, tell your surgeon – hypoallergenic options are available.
On the NHS, the surgical team selects the implant based on clinical guidelines, hospital contracts, and what they consider best for your case. You generally cannot request a specific brand or type. If having a choice of implant is important to you, this is one of the advantages of choosing private treatment, where you can discuss options with your surgeon.
In a fixed-bearing implant, the polyethylene cushion is attached firmly to the metal base. In a mobile-bearing design, the cushion can rotate slightly, which may allow more natural movement. Both types have excellent long-term results. Most surgeons in the UK use fixed-bearing implants as the standard choice, with mobile-bearing reserved for specific cases.
Want to compare private hospitals and prices near you? Use our knee replacement hospital directory to compare 162 private providers across the UK.
This article is for information only. Always consult your GP or a qualified healthcare professional before making health decisions.
Compare weight loss injection costs in the UK for 2026. Wegovy, Mounjaro and semaglutide prices… Read More
Spondylosis Symptoms and Treatment: Causes and Evidence-Based Options Understanding spondylosis symptoms and treatment options is… Read More
Learn about overactive thyroid symptoms, diagnosis and NHS vs private treatment costs. Expert guide for… Read More
Dental crowns cost 282 pounds on the NHS or 500 to 1,500 pounds privately. Compare… Read More
Learn how to use the NHS e-Referral Service to choose your hospital, compare waiting times,… Read More
Explore the 10 most common surgeries for over-50s in the UK, with 2026 NHS waiting… Read More
This website uses cookies.