Clay: Over the past ten years you have seen a lot of metal-on-metal hip implants. Several years ago an attempt was made to put a metal-on-metal artificial hip together, and that was supposed to last forever, or last a whole lot longer, and it turned out that it was problematic. And I know you have had many patients who have had that [implant]. What did you see out of the metal-on-metal hip implants when they were failing?

Amy: Again, the first cardinal sign that I saw was chronic pain, an inability to weight bear normally through that joint. So even after normal hip replacement, the patient should be able to weight bear through it. It should not feel like they collapse on that hip, and so a limp that never resolves or an inability to get away from an assistive device. So, I had a patient in her 50s that could not get off a walker. She was 50. She was playing tennis five days a week before she had her hip replaced. Yes, with the metal-on-metal she suffered metallosis and she had an overt failure of that joint replacement. She was a candidate for this new [metal-on-metal implant], now widely known to be a bad device, because she was so young, active, fit, and healthy. It was supposed to last for longer. It was supposed to allow her to have more function larger range of motion, less risk of dislocation and all of those things. So as we know, that did not really work out so well.

Clay: Yes.

Amy: So the folks that had the metal-on-metal problems, metallosis was the biggest problem that ended up causing really frankly catastrophic changes in these people’s lives because the metals in the two appliances, they ground on each other and it leaks metal, particularly cobalt. That was a big metal that became known to become systemic and to basically create toxicity in the tissue surrounding the joint.

The metal would basically eat or erode away musculature bone, osteolysis was one of the biggest problems where it caused bone to basically just break down and be eroded away. I was actually in the operating room and saw some revision of a hip that experienced metallosis. And in the revision the musculature that was away from the hip, so when you go in to do a hip replacement, obviously, it is an open field and so you can see all of the connective tissue all the layers of musculature of the capsule of the joint this particular patient.

The capsule of the joint was this dingy gray looking color. You knew inherently. You did not have to know anything about science or medicine to know that it is probably not supposed to look like that. And what is astounding was how far away that metal leached into the musculature and so because it is toxic, because it is corrosive, that tissue had to be ripped [out]. It had to be excised. So some people lost part of their musculature and some of it was very important musculature around the hip in regards to stability and mobility restoration in the hip.

So, because the metallosis affected the bone, revision surgeries then became a bit tricky because, so when these folks went in for their first hip replacement, they had this beautiful landscape. They had a bad hip. They had a bad articular surface, but the landscape around it, and by that I mean the bony components that are going to hold that new joint, they were healthy. Otherwise, they would not have been a candidate for a hip replacement. Okay, so they had a healthy landscape to put those two new pieces in the socket. The acetabulum and the femoral head. So, once the metal started breaking down some of the bone, now all of a sudden you have got a landscape. It is not all that great in regards to the how to receive this new joint. So these folks had significantly limited post-op. They had to protect those joints dramatically for long periods of time so that could allow this bone that had really taken a hit to grow into the new prosthesis, which is how you heal a hip replacement. So, it made the post-operative course significantly different than a primary hip replacement where you walk immediately after surgery. I mean, I have seen patients ten days post-op, that are already on a cane and have a pretty decent gait. So–

Clay: Well, that is kind of horrifying, a revision is one thing but a revision when the whole landscape of the hip and the thigh and the leg and all that area is severely compromised. It makes the revision surgery less likely to be successful. So, that gets me to this question. I know you have seen it quite a bit. Tell me what the rehab might look like and I know it is different for all people. But what might the rehab look like for a person who has to get multiple surgeries on the same hip? I know it is compromising. How would it be compromised?

Amy: So that same patient when they had the first hip put in, when as soon as they started physical therapy within 24 hours of their surgery. They would be putting weight if they are usually what is called “weight bear,” as tolerated. So basically, we want you putting weight through that new joint. So as much weight as you feel like you can safely place through that leg using a walker, because everybody starts out on a walker, their weight bear is tolerated.

So, that is in the primary hip replacement that is uncomplicated. In just a plain revision, they can be non-weight-bearing for four to six weeks. So just right out of the gait. They are not putting any weight at all through it for four to six weeks. In the cases where these folks had really substantial metallosis, sometimes that non-weight-bearing was extended 8 to 12 weeks. And now you are talking about being completely non-weight bearing which, by the way, is very difficult to do.

Clay: Yes.

Amy: It is really hard if you think about how difficult that is for your upper body and for your contralateral side, for that other leg to be completely off that leg for anywhere from six to twelve weeks. And the reasoning is because that landscape they wanted, the surgeons wanted, every opportunity for that bone to accept that new part for it to heal because bone is live. So it grows into the prosthesis, into the implanted part of the prosthesis.

So they want that bone grow in because over the course of time, that is where the fixation actually lives. That prosthesis becomes incorporated into the bone itself. It great becomes part of that bone. So that is one of the biggest things that occurs postoperatively in those revisions. And so, then you have to think about everything that happens with that revision. So let us say your non-weight-bearing for six weeks, well, if you took your very healthy hip and you got off of your leg for six weeks, you would be astounded at how much strength you lose.

Clay: All right.

Amy: It is astounding through the entire extremity. And so there is profound strength loss.

Clay: So what is your medical opinion about the likelihood that a follow-up surgery or revision surgery will be successful? I mean does the chance for success just drop through the floor once there has been a failure of an artificial hip? Such that you say to yourself “My goodness. This person is going to really struggle,” or is it case by case? And in a lot of cases revision surgery can be fine for a patient.

Amy: I think that any joint replacement hips included the first one that you get because of that pristine landscape is the best chance you have to have a great outcome. Every time that that surgeon has to go back in, the opportunity for a great success go down.

Clay: Right.

Amy: And that is just the way it is. But the problem is that, like for the folks that had these metal-on-metal joints, they did not have an option. I mean, they were in such profound pain. The debility they had to get that hip taken out. And they just basically had to deal with whatever that metal did to the surrounding tissue and they had to try to protect the healing tissue the best they could and understand that their outcomes were going to be less than perfect.

Clay: Right.

Amy: Not what they had planned. Not what my fifty year old patient who had every plan of going back to the tennis court because that is why she had a hip replacement, because we know that she can go back to doubles tennis.

Clay: Right. Did not happen.

Amy: No, matter of fact, she was just happy frankly at the end of the day after a exhausting very very physically and emotionally challenging rehab process. She is happy to be able to walk and to not feel like she has a nail being driven through her hip every time she way bears.

Clay: I see.

Amy: So her measure of success changed dramatically after her revision.

Clay: I bet. Well, let me try to end on a slightly more upbeat note. Have you seen better outcomes in the last few years since we have learned what we have learned about metal-on-metal hips? And have there been fewer revision surgeries among your patient population?

Amy: There absolutely have been. As matter of fact, it probably in the last four years, I have had quite a few patients that have not even needed to do anything with me postoperatively. They were strong enough, healthy enough, and had prepared themselves for their surgery enough that they did not even need to do PT. Basically, they just had to protect their hip for a little bit, gradually get their weight back on it. And so, there is no question that the hip surgery that is going on right now, the total hip replacement surgeries, and I am seeing are phenomenally successful. If we look at the whole spectrum of success, I think the last that American Academy of Orthopedic Surgeons was a 95% success rate. I mean that is pretty high success rate for a very dramatically large spectrum of people [aged] 11 to the 90s. So, you know, it inherently has great outcomes. It is just when the outcomes are not great, it is bad.

Clay: Yes. I have seen it in my work as well. This is what I wanted to talk to you about today. This has been fantastic.

Amy: Well, I hope I answered your questions adequately, and I am happy to talk with you.

Clay: Well, thank you so much and who knows, if I have another subject to discuss, maybe we can do this again one day.

Amy: I would love to do that, Clay.

Clay: Well, thank you Amy. I really appreciate your time.

Amy: My pleasure. Have a great night.

Clay: You too.

Note: You can also listen to this conversation with Amy Dougherty in my podcast. If you want to talk about a possible defective artificial hip case, call me: (919) 830-5602.

Safe and Unsafe Activities and Sports Clay: What are some sports that you would discourage [after hip replacement surgery]? I know there is a huge range of results and people who are dealing with certain physical issues. But are there any sports you’ve seen as a physical therapist that you say “Do not do this after hip replacement surgery?”

Amy: Oh absolutely and just to clarify my youngest total hip replacement patient was eleven. This child had a very aggressive cancerous tumor that invaded her hip, and so she had what is called a Ewing sarcoma. And so, they ended up having to take the hip give her a new hip, and her big goal was she wanted to be able to drive a car. I mean that is really important. So, she was eleven when the process started and she did not drive a car. So, and I have treated, I actually had a ninety five year old who had, so the spectrum of age is even greater than thirty five to eighty two.

Clay: Sure.

Amy: But there are absolutely some things that are just absolute no’s. And most of them are things that make sense, like contact sports. So things like football, rugby, soccer. There was a great little study that came out, I think it was in 2011. Anyway, it basically looked at all of these different sports and it reviewed all of the literature and it was looking at what are the things that we know are absolute no-no’s.

Amy: And we know this because the literature shows us that these people had high rates of failure in their hips. Oh and by the way, this recommendation basically it was a systematic review and when they made these recommendations, they qualify them into three categories. So, the first category was not recommended after a total hip and so the contact sports hockey, football, soccer, rugby, any long distance running. And that just make sense.

Amy: A lot of people take a toll on their hips by doing a lot of running, and that does not mean that running causes hip arthritic changes that create a total hip that necessitated total hip replacements. Do not misunderstand that, but there is a wear and tear process that goes on with people that are running hundreds of miles a month. So, singles tennis, it gets down to just the numbers of steps that go through that new part; racquetball, squash, snowboarding, and that is because of the risk of dislocation for snowboarding.

Amy: High impact aerobics, fast pitch baseball and softball, because of sliding and contact. The kicking that is involved in many of the martial arts is not recommended. Water skiing and handball. So those are the things that under the category of not recommended. And I will tell people flat-out “Listen, you had a bad hip, you have gone through this process to get a good hip. Be nice to it, protect it.” I understand that you are putting yourself at great risk of early failure or other complications, like dislocation and things like that that necessitate revision. So that is in the not recommended category, and then they created this other category that they call “recommended with experience.” And this actually, again, makes sense. Cross-country skiing and downhill skiing, that is not the time to start learning to ski after you have had a new joint. Now, if you have been a lifelong skier and you have the experience, by all means do it. Make a choices. Mogul fields are probably not a great idea.

Clay: Right.

Amy: If you can cross country ski downhill ski safely. Doubles tennis again, not the time to take up tennis if you have never played in your whole life and you finally have a new hip. Now is not the time to take that up. But if you have been an avid tennis player, so I would absolutely and I have a lot of patients that have gone back and my brother included in that category who has gone back onto the tennis court with a joint replacement.

Amy: Ice skating not hockey. But ice skating is okay if you have experience doing that, things like rollerblading same thing kind of inline skating and Pilates. So those are things that we recommend that are qualified as recommended with experience. I will also add now, this study came out, this recommendation, systematic review was published in 2011. Surfing goes into that category. So if you are a surfer, absolutely if you have experience on a board, you are absolutely prepared to get back on that board after a hip replacement. Not the time to start introducing that into your sport life.

Clay: See it makes sense that if you have got experience you can keep yourself from potential injury.

Amy: Precisely, and then the list of things that are highly recommended because again, you know when you are in the rehab world what you realize that people go through the surgeries for they do it purposefully and it is usually to return to some type of function or activity, that they are arthritic or their painful joint would not let them take part in, so golfing, swimming, doubles tennis, stair-climbing, so like the elliptical walking, speed walking hiking, stationary biking, bowling, these are all things that are highly recommended. We want you to go back to these things because they are going to be healthy for you. They are going to sustain the strength in the mobility that you have recovered at that new joint. But they are also going to be safe for it. They are not going to put your new joint at risk.

Clay: I see. Well that gets to the point that staying active is absolutely essential. That you do not want to pick up downhill skiing necessarily, but you absolutely after hip surgery want to be active in something. And so, it is good to get going.

Amy: I am a physical therapist. I think we all should move. We should move, that is what our bodies are designed to do. They are not designed to sit and be sedentary. They are designed to move us through space.

What It Feels Like When Artificial Hips Fail Clay: Well, that is right. So, I have known you for quite a while and I know you have had patients that have had hip replacement surgeries fail. Can you tell me what symptoms you notice when a patient might come in and say “I had surgery a year and a half ago or two and a half years ago and something feels different. Something sounds different”? Talk about artificial hip failure.

Amy: Sure. Absolutely, well probably, so there are different reasons that hips can fail. But the number one thing that people complain of is pain that is out of context to what they should be experiencing at that point during the rehab process or during the recovery process. So obviously, you have had a joint replacement. We expect it to be swollen. We expect it to hurt. We expect it to be sluggish. It is not going to move well.

Amy: So, there is an expectation of some pain following the surgery but there is a point where that pain should be resolving. And it should be integrating and it usually lives as the tissue is healing. So the bony tissue is healing, where the new hip implant, the new appliance, has been mated with the bony surfaces, so that healing takes place and then the soft tissue around that joint is healing and you are becoming more mobile. So, that pain should frankly just gradually decrease until it is gone.

Amy: When someone’s hip has failed, that does not happen. The other thing that is really interesting, or I think that is telling, is that typically these patients have pain even when they are not moving, and a significant amount of pain. Now again, initially immediately after the surgery, it is normal to have night pain that makes it tough to be comfortable. But after a couple of weeks after a hip replacement, you should be able to sleep for periods of time. Many times people have so much pain that they cannot sleep. Like, it keeps them awake.

Amy: Nocturnal pain is always something that worries me because at the end of the day, we are kind of hardwired to get rest but pain prohibits that. To me, that is, I am always going to look very carefully at this patient because that should be something that initially pain management should be taken care of, so medications, icing, making sure that your activity levels are appropriate for that stage of your recovery.

Amy: If all of those things are in line, and this person is still telling me, “I slept an hour.” I do not like that. Immediately that is a red flag to me that I need to take a really close look at what is going on with this patient. So, pain is out of context to what the pain level should be at that point. Pain that is occurring without moving. So, it is not mechanically driven pain.

Amy: Any type of mechanical clicking, grinding, and these are things that people will sometimes report, you know, it clicks, it grinds, it snaps. Some people have reported they can actually feel it move. So those are things that tell me that something organically is not healthy in that hip, in that newly replaced hip.

Clay: Let me follow up on that. Is it your medical view that a successful hip replacement surgery should end with no pain at all after the rehab is over, and after the recovery is over that there should be little to no pain?

Amy: Absolutely, and when that does not happen, if let us say, and I have seen this before, I have had people show up a year after hip replacement and they say, “You know my hip still bothers me.” And upon assessment, there might be a really good reason. You are profoundly weak, you did not build the strength around this joint to give it stability. So your pain is actually not in the actual hip itself, it is in the pelvis because of the forces that are going through hip joint that and the musculature of the strength is not adequate to control those forces.

Amy: So, sometimes there is a reason that someone has got pain a year later. But in the absence of something like that going on, no, you should not have pain. That is the whole reason that you have this new hip put in. So if you are continuing to have pain, I tell my joint replacement patients that it takes a year to recover from these big surgeries. But that is a pretty reasonable expectation from any orthopedic surgery, be it a rotator cuff repair, an ACL reconstruction, certainly a knee or a hip replacement, or a shoulder replacement. It is not uncommon to have some discomforts and stiffness and irritability up to a year, but after that, no, it should not happen. It should not be painful. So there is a very big difference between, “like I am still aware of it” versus “this thing I can not put weight through it. It hurts so much. I can not walk. I can not sleep. I can not ascend or descend stairs. I can not lift my leg to put it into a car.” These are things that I have seen in failed hips.

Clay: Yes.

Amy: Or even just give way where you weight bear on the leg, on that failed hip, and they will fall. That is a result of a failure.

Part 3 next week.

Hip replacements often use a variety of exotic metal alloys or ceramics to recreate the ball-in-socket mechanism of the human hip. A total hip replacement will typically consist of four parts:

• The socket (or acetabular component).
• The ball (or femoral head) that goes into the socket.
• A liner for the socket that is in direct contact with the ball.
• A stem for the ball (also known as a femoral stem) that connects the ball to the thigh bone (femur).

The liner is placed into the socket and the socket is placed into the pelvis. The ball attaches to the stem and the stem attaches to the femur. The result is a total artificial ball-in-socket hip replacement.

Sometimes, these hip replacements don’t work as expected. One such example comes from Zimmer US, Inc. and related companies (which we’ll collectively refer to as “Zimmer”). Many patients have reported problems with a particular set of Zimmer femoral head and stems.

What’s Wrong with Zimmer’s Artificial Hips?

At issue are two femoral stems: the M/L Taper Hip Prosthesis and the M/L Taper Hip Prosthesis with Kinectiv Technology. When either of these components is paired with the Zimmer VerSys Hip System Femoral Head, many artificial hip recipients have reported a variety of problems, such as:

• Metallosis (elevated metal levels in the body)
• Osteolysis (destruction of bone tissue)
• Pseudotumor formation

Often, any of these problems require revision surgery, which is surgery to replace the failed implant. It’s believed that many of these hips are failing due to corrosion, trunnionosis and the release of tiny bits of metal at the point where the femoral head connects with the femoral stem.

Have Patients with Failed Zimmer M/L Hip Replacements Taken Legal Action?

Yes. There have been hundreds of plaintiffs who have filed suit against Zimmer alleging defectively designed and manufactured hip components, Zimmer’s failure to warn patients and doctors about the risks of using the hip replacement and that Zimmer did not properly test the artificial hip components.

With so many lawsuits consisting of similar injuries and allegations, along with a single (or small number) of defendants, our court system has a special system in place to consolidate the cases for pre-trial matters. This consolidation is called multi-district litigation, or MDL.

The purpose of MDL is to handle much of the pre-trial matters, such as discovery, in a single court with a single judge. With a single judge handling these pre-trial matters, the cases can be processed more efficiently, as the judge’s decisions will apply to all cases at the same time.

The ultimate goal is to reach a comprehensive settlement that resolves all of the cases fairly. One way to do with is by having several bellwether trials. These sample cases are supposed to be representative of most of the cases in the MDL. Therefore, how they turn out can serve as a signal of what the plaintiffs and defendants can expect if their respective cases go to trial.

How these bellwether cases turn out will shape how settlement negotiations will go. As you can imagine, the better they go for the plaintiffs, the more negotiating leverage plaintiffs will have during settlement talks.

Right now, the Zimmer lawsuits involving the M/L Taper Hip Prosthesis, the M/L Taper Hip Prosthesis with Kinectiv Technology and the VerSys Hip System Femoral Head are in MDL in the US District Court for the Southern District of New York before Judge Paul A. Crotty.

Zimmer MDL’s Current Status

The Zimmer MDL is in the discovery phase, with the first bellwether trial scheduled for January 25, 2021. But if this date is pushed back, don’t be surprised. It was originally scheduled for September 14, 2020, then pushed back to October 19, 2020 and now has this date in early 2021.

All of this to say, there’s a lot of discovery and pre-trial motions to complete before a single trial takes place. As new developments arise in this case, I’ll post an update in this blog. Until then, there’s a long grind of pre-trial matters to get through.

Call me to discuss further: (919) 830-5602.