What do you mean with the word "best"? Best has an objective and a subjective part in the way that the assessment can be based.

The subjective characteristics are the familiarity the surgeon has with the components and the surgical technique.

The objective are the performance of the prosthesis in the different joint registries and their observations of published literature.

On top of this someone has to determine if is talking for primary or revision components because the performance as well as the indications are different.

All companies will say that their prosthetic are the best in the world, but someone has to be critical of what is hearing and correctly to find the answer, but the answer comes through the research of registries such us Scandinavian, Australian or British.

Dear George,

Thank your for you response to my question. I need to know about the performance in primary surgery though the subjective characteristics are important, too. How can I obtain the registries results?   

All registries (Natinal Joint Registries) have their websites.  There are three Scandinavian with more prominent the Norwegian and the Swedish, the Australian and the UK or British. Just search for those in the internet by typing National Joint Registry and then the country. Happy searching

I agree with comments from George Zafiropoulos regarding the National Joint Registries. Another good source to review medical device reports submitted to the FDA by mandatory reporters (manufacturers, importers and device user facilities) and volunteers is MAUDE database (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/TextSearch.cfm).

I agree - these are good sources of information.

the Australian registry report (https://aoanjrr.sahmri.com/annual-reports-2015 ) is probably the most comprehensive of all registry reports by pure volume of procedures covered. Note however that "best" highly depends on the actual condition of the patient as well as the experience of the surgeon. Registries are probably best to detect particularly bad devices due to outliers in the failure rate, while for the good devices it mainly depends on the hands of the surgeon. This is also why the report only reports on "PROSTHESES WITH HIGHER THAN ANTICIPATED RATES OF REVISION"  see page 195ff in the Australian registry report "It is evident from Registry data that most prostheses have similar outcomes. A number, however, have revision rates that are statistically higher than other prostheses in the same class. The Registry identifies

these as ‘prostheses with a higher than anticipated rate of revision’. "

https://aoanjrr.sahmri.com/annual-reports-2015

Various national joint registries will tell you the "worst" knee replacement prosthesis with higher than expected revision rates (Just Google them as suggested in earleir answers). As far as "best" prosthesis is concerned, most have similar reported outcomes. One must not forget that it is a combination of patient factors, surgical environment, familiarity of surgeon with instruments and prosthesis design, level of surgical training etc which are going to determine what is "Best" for the patient.

Narinder Kumar's answer is the most comprehensive, but in any case, thank goodness for the registries. I am retired, but was involved for decades in TJA r&d. It has been sadly amusing that failed design principles are revisited every few decades, the worst recent case being the revival of metal-on-metal hip systems. 

I agree with this approach but usually the representatives of every company have enough literature to back up their prosthesis. We need independent studies and as these are not possible to see the light before ten years  (to be allowed to be considered "influential") the best results can come out from the registries because there we can observe the trend of the behaviour for every prosthesis much more  quicker. 

I do agree with George Zafiropoulos and Vigano, there is not a simple answer. A lot of factors are involved in the final results. Sometimes is right Surgery to the wrong patient, so we will have a bad result. All the variables must be addressed. Besides the industry the surgical techinique and correct indication must must be respected. 

Reza,

With all do respect, you question demonstrates a lack of experience and understanding with regard to total knee design or for that matter any total joint design. The first question needs to be when is a total knee indicated ?Or what type of knee design classifications are there and when are they indicated?

As for any specific design and what is best can never be answered in my opinion because the main factor for a good outcome is the surgeon. The individual surgeons training and experience is the critical factor. Technique, technique is more important that design or fixation method.

Example some surgeons can get good results with partial knee arthroplasty and some cannot. Most contemporary knee designs function very well it is the surgeons decision when to use a rotating bearing, fixed bearing, posterior stabilized or cruciate saving design.

Switching knee systems causes some problems if the surgeon is not familiar with the individual instruments. Another example all poly cemented tibial components have had very good results over the years but industry has pushed modular tibial components for theoretical advantages and pricing and over the years has caused significant problems and raised surgical cost.

You will find as you get more experience that there are no simple answers but the one  constant factor to a good outcome is the surgeon, in my opinion.

Regards,

Tim

Naturally, the selection of the right implant itself, is of vital importance, however, it is worth keeping in mind at the same time, that even the worst kind of implant, that is to be applied (implanted) properly with care and experience, will prove more resilient in the long run, compared to the best-quality one, implanted unprofessionally. Therefore, to confirm, the best implant is the one that has been implanted using familiar techniques.

When we look at the complications as a result of endoprothetics, we can assume that  it is the technical mistake rather than the design or the brand directly responsible for the problem. 

I quiet agree with Jacek

Is anybody using implants from Spain, China or similar? We have recently been bombarded with a series of unknown or newly marketed implants from companies that have shown up in the market as of the last 7 or 8 years and the insurance companies are pushing for us to use them since costs are usually 40% less than any ZimmerBiomet, Depuy, Smith Nephew or likes.

Rising health care cost has very little to do with the individual cost of implants.Insurance companies, purchasing agents and even health care administrators are very short sighted when it comes to cost containment. They are more interested in what they can save on this years budget compared to reducing actual health care dollars.

I would suggest saving O.R. time and being efficient in the O.R. will reduce O.R. time and turnover time saving more money than the price of any third world implant.

It is estimate in the U.S, that O.R. time can cost between $150 to $300 per minute. The most effective action surgeons can take is to do what you do best with the equipment you know best. The cost of a revision wipes out any potential implant discount one receives. Reduction of health care cost is  achieved in improved long-term outcomes not short term discounts.

The results themselves depend a lot of factor, such as surgeon expertise, the right patient, the post op regimen ie. physiotherapy and the implant quality, at Brazil we have a great deal with the national health secretary, where they obligate us to use the implants made in Brazil, and the quality is not so god as we would like, and as you can see there is not only one factor to success in knee replacement, it is multifactorial.