42 yo M with ?'s: oxinium, balance, feel, ROM

[Zad]

Hello,

I am 42, have OA in my left knee from an accident at age 13 and I am just starting to learn about TKR as a possible, future treatment options. As this is all new to me I have a bunch of questions and I am curious to hear from those of you who can answer the following questions:

1. From the reading I have done, the Oxinium knee is getting lots of good press. Is this press justified or just marketing hype or too soon to really know?

2. I am curious to know if having a prosthetic knee feels different. Is your balance or proprioception affected or does it feel "normal."

3. I have read that some knees give almost a full range of motion. Is this true in practice? Can any of you squat to your heels with a TKR?

4. It would seem to me that having metal on plastic would provide less cushioning. Do your prosthetic knees cause more jarring with each step or is this not noticeable?

Thank you.

 

[Surfsister]

I'm almost a month out of surgery. I'm a 45 year old surfer. My doctor told me I would know that I had a prosthetic knee. He said it would feel different than my original knee. Frankly, it feels a hell of a lot better than my osteoarthritic knee. I still have limited ROM but that is improving with hardcore physical therapy. I will probably always have limited ROM. After my original injury at 17, I never regained full ROM and it's thought I probably won't be able to do so now.

The knee feels normal to me thus far. Prior to surgery, my knee would catch. The pain was intense. That catching is gone. The bone-on-bone pain is gone. The surgical pain is subsiding.

I have no idea which knee I have. Frankly, I left it up to the doctor to decide. My main concern was that the doctor understood my lifestyle and recognized what I needed my new knee to do. Since I know nothing about prosthetic knees, who am I to shop for one? What if one knee that works well on men doesn't work well on women? Does anyone put that in literature or is it something the surgeons understand? It was questions like that which made me feel it was best to let the surgeon decide.

Don't hesitate. If you're in pain, just do it. It's worth it. I want to return to surfing so my physical therapist pushes me until I'm just about in tears. But recovery is usually easier than that. You have to determine what you want from your new knee (within reason). Then just make the drop, eyes wide open.

 

[Texas]

I have a stryker knee. Seems to work great. Actually me, I havent heard of the Oxinium, but it maybe great. To me it feels no different except I can move and it doesnt hurt. You can have full range of motion with the right physical Therapy and hard work. I have more cusion now then I did with my old knee, and less pain. I dont notice a difference at all. Hi and welcome. Others will be on to share as well. I hope you get the success you are looking for. The life that you want, and deserve. To be able to do what you want, with out all that pain. Please post anytime with questions, you couldnt ask for better more caring bunch of people here. Good luck I hope you feel better soon............Kim

 

[Jamie]

Welcome to the forum, Zad.

You need to focus on finding the right surgeon rather than worrying about which type of knee is best for you. That's what you expect the surgeon to be able to determine for you. And, frankly, most of them are very similar anyway. It's the surgeon's knowledge and skill that count!

My knee at one year out from surgery does not feel "fake" at all. It just feels like my .... KNEE.

You should be able to regain whatever range of motion you had going into surgery assuming you do not develop scar tissue. Even if you do, there are things that can be done to improve your range of motion in recovery. So you can plan to do all or most of the activity that you did prior to surgery. But, as Surfsister said, you need to discuss your expectations with any surgeons you interview.

I notice no jarring...the new knee works great.

Good luck and post here whenever you have a concern or question. There will always be a group of forum members ready to discuss things with you.

 

[Josephine]

1. From the reading I have done, the Oxinium knee is getting lots of good press. Is this press justified or just marketing hype or too soon to really know?

Not quite sure what you mean by 'too soon to really know'. If you're referring to the amount of time they've been around or in use, the majority of prostheses meaning the ones most in use, have been on the market since about 1980 or thereabouts. How long a period do you want for proof of reliability!

Frankly, all knees are pretty much equal. All have about equal longevity and performance. If they didn't the surgeons wouldn't use them. Remember their reputation and livelihood depends upon their performance. I've often said, and will say again, that choosing a knee is a skilled job and one for the surgeon. It's what he's trained years for, to know which knee is suitable for which occasion. Of course the patient should research and know what's on the market but when it comes to the surgery, your choice should be more focussed on getting a good, experienced and skilled surgeon and then accepting what he thinks is the most suitable for you.
For more on this, read this thread How to choose a surgeon and a prosthesis

2. I am curious to know if having a prosthetic knee feels different. Is your balance or proprioception affected or does it feel "normal."

That can differ from person to person but in my experience, by far the greater majority of knee replacement folk notice little or no difference between the original knee (when good!) or the artificial one. A very few report an awareness of an artificiality, for want of a better term, but never heard it more than commented upon. Thus one would suppose it's not an overwhelming experience.

Like Jamie, my new knee feels just like 'my' knee!

3. I have read that some knees give almost a full range of motion. Is this true in practice? Can any of you squat to your heels with a TKR?

That can be influenced by the amount a person is overweight though I've known skinnier people get up to 150 degrees of flexion. But even I can get 140 though my leg is (ahem) on the large size!

However, doing a heel squat is a little different and it could be hampered by the presence of the incisional scar which won't be quite as stretchy as the unmarked skin and deeper tissue.

4. It would seem to me that having metal on plastic would provide less cushioning. Do your prosthetic knees cause more jarring with each step or is this not noticeable?

Less cushioning than what? I'm not aware of any knee that isn't metal on plastic. The high molecular weight polyurethane which is used is strong and durable against wear and impact whilst giving a good cushion for the weight bearing. Plus the nature of the design means that if wear does occur, the plastic insert can be replaced without interfering with the metal components.

As for the jarring, as said above, generally there is no difference between the new and the natural knee. If properly fitted, there should be a reasonably firm fit once the insert in place. It's one of the steps of the operation for the surgeon to trial fit two or three thickness of insert to see which gives the better fit. When selected, the actual prosthesis is put in place.

Even after this, a very few people report some clunking, clicking or popping noises on occasions, especially in the early stages. These either settle as the knee heals or the patient gets accustomed to it and 'tunes it out' of their awareness. I myself had such clunking in the early days but only when I moved my leg around in bed, being when I wasn't weight bearing. It seems to have mostly faded off now.

 

[Texas]

Yes yes I didnt even think of that but i had a not so great expierence with my x Dr I wish I would have checked him out more. so yes the sugeon absolutly !!!!!!!!!!!! Check Check again. Jo always knows !!!!!! That kind a rhymes....... Kim

 

[Gringo]

Well, in my search for an OS, I found out that for the most part a given OS will tend to use a specific manufacturer's product. This is because they undergo a lot of prosthesis-specific training on these things, and probably don't want to try to be an expert on several different products. They have these tool and fitting kits that are quite extensive, and are specific to the manufacturers model that they are using. I would liken it to going to a factory trained mechanic for Ford, and expecting him to be as expert on Volvo as he is on Ford. There must be some OS's who cross train in different products, but I would think it makes more sense all around for them to find a supplier who offers a good set of options for all occurences, and stick with that one.

So, in that case, if you really think you want a specific knee, you would just go to the website for that manufacturer and look up the section where they help you find a doctor.

Since you asked about Oxinium, and since I am interested in what goes into my second knee in a few months (I have a Stryker Triathalon in my first one) I did a search on that. So now I know it's a ceramic coated knee, being promoted as being longer wearing and harder and therefore more suitable for younger patients. Hey, I don't know about you, but this set off a couple BS alarms in my head. And I have pretty good BS alarms.

If you coat a metal knee with a ceramic substance, you now have a more complicated knee. There is another substance in there. Coatings can come off. Paint is a coating, for example. Ceramics chip. The India site I was first looking at said that when wet, ceramic is smoother than chrome. This makes me ask..."Why"? And do I want a knee that needs to be wet to work?

You also asked about the hardness of it, the fact that the plastic inserts won't have as much "give" or cushioning as the natural knee. Well, if you keep reading and searching online, you will eventually find out what I found out. Replacement parts for human beings are never quite the same as the original parts. That is because the original parts are organic. Lets think about knees, specifically. There is no way the plastic insert that replaces the meniscus functionally can be as soft as the original. And it doesn't need to be. The original meniscus is cushioning between two live bones. The plastic insert is a bearing surface between two pieces of metal. I would think harder is better, in this case.

One last comment, while looking up the Oxinium knee, (because I really am interested and will continue to look into it as a possibility for my own second TKR) I ran across a situation where an Oxinium knee is being withdrawn from the market due to failures.
Check this out:
broken link removed: https://www.alexanderlaw.com/smith-nephew-knee/index.html

Gosh, that wouldn't make me feel too good about it.

I think the most logical thing to do is for you not to try to wade through the knee manufacturers' marketing claims, and just concentrate on finding a good surgeon. Let him pick the parts.

 

[Gringo]

Still looking into it, I found this pretty informative:

https://www.essexkneesurgery.co.uk/oxinium-knee-replacement.php

But note that this stuff has only been out there a few years. I think in my case, I would prefer something with a little more history. Smith and Nephew seem to be the only company that uses this stuff, and have only been using it since 95.
broken link removed: https://www.medicalnewstoday.com/articles/35433.php

From a consumer standpoint, that's kind of dangerous. If they go under, where do you turn with problems?

That doesn't mean it isn't the cats meow, of course, but I plan to really look into it before my second TKR. Hey, maybe I will end up with one of each and see which one lasts the longest...

 

[Jamie]

Yep, Gringo. I agree with your last comment about searching for the right surgeon. Those websites about recalls are generally put out there by lawyers trying to drum up business. You have to watch....many of the lawsuits and recalls occurred years ago. It always pays to be an informed consumer, though, and doing research about what's out there is important!

 

[Josephine]

Well, Gringo - you got some really good points but a couple need to be amended a little.

First about surgeons being only trained on one prosthesis. I had to chuckle at that! When a doctor decides to go into orthopaedics, he has to do his training with a number of different senior surgeons. Over here we call the trainees 'registrars' and the seniors 'consultants' so forgive me if I stick with what comes naturally!

Each consultant will be using a different prosthesis and thus the registrars will get experience with all sorts of implants, different types, cemented and uncemented, different types of materials. Even when he reaches the end of his training, he will still be working with consultants and being exposed to yet more different types. In the UK, he could work with as many as 30 or 40 consultants during this 5 year training scheme.

It's also during this time they will get exposed to different surgical techniques and incisions, even different ways of closing the wound. Along with that, he will also be taught about his consultant's experiences, successes and failures, ways of dealing with problems, reasons for choosing X, Y or Z prostheses or anything else. Thus, by the time he becomes a consultant in his own right, he will have made up his own mind which of all these he thinks are the best and why. And then he'll have added to that pot all the other information and experiences he has gleaned from other colleagues, conferences and meetings, reading professional journals and doing his own research, both laboratory and empirical. Here in the UK they have to have a number of articles and research papers published in order to prove their academic standing. That's how he becomes an expert in what he does. No surgeon is a 'one trick pony' else he wouldn't be an expert, even on the one prosthesis he favours. Those whose performance or techniques are below par are usually those who have not had a good range of such experience, haven't absorbed it properly or haven't kept up to date.

You also said 'why do I want a knee that has to be wet to work?'. Honey, all artificial joints need moisture to work to their optimum. Mostly the synovial fluid will doi just nicely but it might take a short while for it's production to get into gear and the makers ceramic implants have recommended a little jump start on nature.

Finally, that class action on the Oxinium Genesis II or Profix II is the uncemented version that is concerned as the ingrowth matrix, the Oxinium, is under suspicion of poor performance. It was reported that 30 out of 30,000 patients had loosening which, at 1%, is in the upper reaches of unsatisfactory outcomes normally being rated at 0.5-1%. The cemented version is just fine.

However, just so you know I'm not knocking your otherwise excellent post completely, I would applaud the way you put these two comments. Mirrored my thought exactly.

There is no way the plastic insert that replaces the meniscus functionally can be as soft as the original. And it doesn't need to be. The original meniscus is cushioning between two live bones. The plastic insert is a bearing surface between two pieces of metal. I would think harder is better, in this case.


I think the most logical thing to do is for you not to try to wade through the knee manufacturers' marketing claims, and just concentrate on finding a good surgeon. Let him pick the parts.

 

[Gringo]

Thanks for the clarifications. I am a layman in these things, and can only report my own experiences. My OS only does Stryker knees. When I was looking at the DePuys knees, they had a link to finding doctors who specialized in DePuy knees on their website. And that's my experience so far, that at the end of all their training, they tend to specialize in one type of knee.

I didn't ask specifically, but I got the strong feeling that if I had wanted a De Puys or other knee, my OS would have sent me to another doctor. I would be willing to bet on it, in fact.

I did ask my OS about the knees with the rotational claims, and he said they were marketing hype. He said all the knees did that, except for one type which is more like a hinged thing. I don't remember the name of it.

I do realize they withdrew or recalled the uncemented knees. But see, that makes me nervous, too. They thought they knew what they were doing with uncemented knees. That bone would grow to it. They were not exactly right.

SO, they also think they know what they are doing with zirconium surfaces, with a thin layer of ceramic. Do they? Maybe. Started in 95, so now they have 14 years experience with them. And they are recalling knees. Maybe I have gotten overly cautious in my old age.

I also see that they are promoting Oxinium revisions, now. I guess I am confused about that, as well. Does a revision entail completely removing the metal components of the knee?

I have been continuing to search on the Oxinium knees, and other than the claims by the manufacturer that ceramic zirconium is slicker than polished nickel/cobalt...I can't find any scientific backup for that. Its slipperier because they SAY so? I dunno. I need more than that.

 

[Josephine]

I'd agree with you completely. Something like not believing everything you read in the papers comes to mind! Goes for websites too ....

 

[Zad]

Thank you for your replies. Very helpful.

Zad.