India witnesses more than 2.5 lakh knee replacement surgeries every year – a significant rise of 2.5 times in the past five years (as per national joint registry estimates). Choosing the right implant material for knee replacements is crucial for long-term success, durability, and joint comfort.
Among the many options available, the “best” material often depends on your age, activity level, bone health, and any existing allergies. Modern knee implants typically use a combination of metal alloys, ceramics, and medical-grade plastics. The aim is to mimic the movement and function of a natural knee.
Common Materials Used in Knee Implants
1. Metal Alloys
The most common metals used in knee implants are cobalt-chromium, titanium, and sometimes stainless steel.
- Cobalt-Chromium: Known for strength, durability, and wear resistance, it can last for decades. It has been in use for more than 5 decades. It is more reasonably priced than newer implants. It is often used for the femoral component (the thighbone part).
- Titanium: Lightweight (⅓ times the weight of cobalt-chromium), more flexible, strong, more compatible with bone, and helps preserve higher bone density, making it ideal for patients with metal sensitivities or for cementless fixation.
- Oxidised Zirconium: It is stronger than cobalt-chromium, has friction half as that of traditional metals, and the surface is as smooth as that of ceramics. As it does not contain nickel, it is a good choice for patients allergic to metals.
2. Polyethylene (Plastic)
Ultra-high molecular weight polyethylene (UHMWPE) is a durable plastic used for the tibial insert – the spacer that cushions the joint and allows smooth movement between metal components. The latest generation of polyethylene is cross-linked and highly wear-resistant, which improves the longevity of the implant.
3. Ceramics
Less commonly used in knee replacements than in hip replacements, ceramic components are extremely smooth (meaning reduced friction and wear) and better suited for patients allergic to metal. Their construction is quite durable to last more than 3 decades, but their risk of getting broken under excessive pressure and noise element limit widespread use.
Which Material is Best?
When it comes to knee implants, there is actually no one-size-fits-all option:
- For most people, cobalt-chromium metal paired with cross-linked polyethylene offers excellent longevity – often lasting 15–20 years or more. Also, these implants are widely available, and more affordable compared to newer materials.
- For younger or active patients, titanium may be preferable due to its lighter weight and better bone integration. Depending on usage, alignment, fixation method, and patient lifestyle, it may even last up to 25 years or more.
- For those with metal allergies, ceramic or oxidized zirconium components may be ideal. While the former may have a life of up to 30 years or more, the latter ones may have a longevity of 25+ years.
Final Thoughts
The best material for your knee replacement depends on a personalised evaluation by your orthopaedic surgeon. Factors such as age, how active you are, body weight, metal sensitivity, bone quality, and medical history all play a role in the kind of implant to choose.
Apart from the choice of implant, key elements that influence the success of your knee replacement surgery would be the experience of your surgeon, whether it is traditional knee surgery or the advanced robotic knee replacement, how religiously you follow doctor-recommended physical therapy and recovery plan, and how active you stay after surgery. The choice of implant material is just one aspect of the knee replacement puzzle.
Apart from that, an experienced knee surgeon is more likely to deliver best outcomes even with standard knee implants than an inexperienced surgeon with the most expensive implants. Consult the best knee surgeon in Chandigarh at Sohana Hospital to know which option will be more suitable for you according to your individual needs.