How Many Types Of Knee Implants Are There?

 

Knee replacement or arthroplasty is a surgical process to resurface a knee that had been damaged by arthritis. Damaged bone ends are capped by metal and plastic parts, which will help in forming the knee joint, along with the kneecap. The goal of this treatment is to provide relief from the pain that had been caused by the damaged knee. This procedure is performed by the best orthopedic surgeons in India.

In knee replacement surgery, an orthopedic surgeon resurfaces the damaged knee with artificial components, called implants. These implants are made of metal alloys, ceramic material, or strong plastic parts.

Implants differ greatly in their design, fixation, and materials. Manufacturers are offering different models and features, which are designed on the basis of a patient’s size and activity level as not one-size-fits-all or even one-style-fits-all. The brand and design used by the doctor or hospital will depend on many factors, including

• An individual needs will be based on the knee problem and knee anatomy, as well as the patient's age, weight, activity level, and general health

• Doctor's experience and familiarity with the device

 

What are knee implants made of?

 

 

Commonly used material for an implant is Metal. There are a variety of different metal alloys being used, few of the common ones are:

Titanium & its alloys

Titanium alloy being biocompatible in nature has been the preferred material. The most popular titanium alloy is used in knee implants is Ti6Al4V.

• Titanium alloy: Mostly contain amounts of vanadium and aluminum in addition to Titanium. Titanium & its alloys have great corrosion resistance, which makes them inert biomaterial (means there will be no change in them after being implanted in the body). Titanium implant can act more like the natural joint, due to which the risk of some complications like bone resorption and atrophy is reduced. This is because of the elastic nature of titanium and its alloys, which is lower than any other metals being used in knee implants

• Pure titanium: Is mostly used in implants when high strength is not needed. For example, pure titanium is sometimes used to create fiber metal, a layer of metal fibers bonded to the surface of an implant which allows the bone to grow into the implant or allows the cement to better bond to the implant for stronger fixation.

Tantalum - This is a type of pure metal, having excellent biological and physical properties. Flexibility, corrosion resistant, and biocompatibility are its main properties.
 

Trabecular Metal: Is a porous material which has been made of tantalum. The pore size of this material helps in bone regrowth, forming a better bridge between the metal & bone. In addition to this, trabecular Metal also has an elastic nature which aids in bone remodeling.

Zirconium

There are two types of Zirconium materials

1. Zirconium alloy and all plastic tibial component

2. Oxinium oxidized zirconium

Zirconium alloy and all plastic tibial component:

Zirconium alloy is being used in a new ceramic knee implant. It is used in combination with an all-plastic tibial component, and not the traditional metal tray and plastic insert, which are used in other knee replacements. It is believed that this new knee could last for approximately 20-25 years.

Advantages:

• Lubrication: This new combination can be lubricated, resulting in a smoother and easier articulation through the plastic.

• Biocompatibility: This is an important property of this material. That is, it is suitable for people who are allergic to nickel and cannot have cobalt- chromium alloy based knee implants.

 

Oxinium oxidized zirconium:

This is the most recent material being used in knee implants. It is primarily a transformed metal alloy having a ceramic bearing surface. It contains zirconium and niobium alloy that is oxidized to convert the surface of the material into zirconia ceramic.

Advantage: As only the surface of the metal has been changed, the rest of the implant component still has a high tensile metal. It is twice as hard as cobalt-chromium alloys, it provides half the friction thus performs with higher quality and lasts for a longer time.

Cobalt –Chromium:

It is an extremely inert, bio-compatible, hard, tough, corrosion resistance and durable material. It has all the ideal properties for a surrogate knee joint.

Disadvantage: The only disadvantage of this material is the release of tiny metal ions due to joint movement i.e. while moving, walking, etc. Mostly these fragments are harmless. But at times, these particles can cause reactions in the human body, commonly in case of those patients who are allergic to special metals like nickel.

Finally, the knee replacement surgeon will be the one to decide, using whichever implant or implants he or she feels is best for the situation and whichever product he or she has had previous success with.

 

What companies make artificial knees?

 

Zimmer persona knee by Zimmer Biomed

Zimmer world headquarters are in Warsaw, Indiana & was founded in 1927.

Listed Advantages:

• Morphologic knee implant designs

• Comprehensive sizing with tighter increments

• Side-specific kinematics

• Cruciate-Retaining and Posterior Stabilized philosophies

Source: ww.zimmer.com/medical-professionals/products/knee/persona-knee.html

 

BIOLOX delta by CeramTec (Metal free arthroplasty)

Ceramtec is a European based private equity firm which founded in 1977. It has its offices in Guernsey, London, Frankfurt, Paris, Milan, Luxembourg and Hong Kong.

Listed Advantages:

• Excellent biological behavior

• No known risk of allergy

• No metal ion release

• No known pathogenic reaction to ceramic particles

• Reduced risk of infection

• Lower wear of polyethylene against ceramic

• High hardness and scratch resistance

• Resistance to third-body wear

• 5 successful years in clinical use

 

Universal Rolflex by Evolutis

Evolutis was created in 1999 by a group of experienced orthopedic professionals.

Listed Advantages

• Femoral Condyles and tibial baseplates are made of Cobalt-Chromium

• Reversible femoral Condyles right and left are available in 6 sizes for cemented use only

• A/P and M/L dimensions, and femoral resections identical to those of the Anatomic version

• Accentuated and highly congruent trochlear groove identical to Anatomic version

• Reversible tibial baseplate right and left available in 6 sizes, including the 3 smaller sizes with short keel

• Center of rotation of tibial insert in the middle of the M/L dimension

• The available tibial inserts, available in 5 thicknesses are made of polyethylene PEXEL moderately crosslinked and vacuum-packed.

• The instrumentation set limited to 3 trays

 

Vanquish Ligamentoplasty by Evolutis

VANQUISH system is meant to facilitate both ACL (Anterior Cruciate Ligament) and PCL (Posterior Cruciate Ligament) plastics through Kenneth-Jones or semitendinous-gracilis autograft techniques. The system is based on a unique and complete instrument set which includes a graft tensioning table, ACL and PCL guides, and strippers among others.

The VANQUISH implants can be combined with one another so as to adapt to the dedicated technique of the surgeon: interference screws, endo-button, and staples.

Listed Advantages 

• Composite of D & L lactic acid, bioabsorbable and biocompatible

• Progressive resorption with no crystalline residues

• Soft thread armless to the graft and the sutures

• Titanium plate with rounded angles to prevent chaffing of the loop and threads

• Made of cobalt-chromium

• Internal spikes for graft stability

• Direct impaction into the bone, no necessary preparation

ATTUNE Knee by DePuy Synthes part of Johnson & Johnson family

The DePuy Synthes Companies is a part of the Johnson & Johnson Family of Companies. The DePuy Synthes Companies have been innovating and discovering for over 100 years.

Listed Advantages:

• Designed to help improve stability and motion.

• It combines the latest in design, kinematics, engineering, and materials to deliver a high level of stability and motion to help patients achieve their optimum range of motion, giving them the freedom to move while remaining very stable

 

Freedom total knee system by Maxx medical

The Freedom Total Knee® System allows patients to achieve high-flexion motion regardless of whether the all-poly or metal-backed tibial component is chosen. This approach provides surgeons with unique component options that deliver successful and predictable results.

Listed Advantages

• Incorporates design that redefines the high-flexion arc of the femur while limiting bone resection along the posterior condyles of the femur.

• Provides a deeper patella-femoral groove for natural patella tracking with or without resurfacing the patella.

• Offers multiple size options that feature dynamically proportioned M/L and A/P femoral components in CR and PS options.

What is the best brand for an artificial knee?

There are numerous orthopedic manufacturing companies today producing different types of implants used in knee replacement surgery. It is recommended that while selecting an implant that is fit for the patient, the following criteria should be seen:

• Your implant manufacturer and product should have a successful track record of use (minimum of 5-10 years)

• Your surgeon must have considerable experience in using this implant before

• As per your discussion with the surgeon and based on your medical condition

The hip replacement surgery cost in India is more than half the cost, compared to other countries offering the same standard treatment. In India, every year 40,000 total hip arthroplasties are being performed. Patients from different countries come for medical treatment in India because of cost-effective treatment. India has some of the best orthopedic hospitals in India and it is a booming medical tourism destination.