Problems with a number of different knee replacement systems have surfaced in recent years. As result, product liability lawyers are reviewing potential claims for individuals nationwide who may have received a DePuy Attune, Exactech Optetrak, Arthrex IBalance or other defective implants.
REVIEW A KNEE REPLACEMENT CASE: Unreasonably dangerous design problems have resulted in high rates of failure and revision surgery for certain implants. To help individuals and families determine whether they may be entitled to financial compensation, knee replacement lawyers provide free consultations and case evaluations.
Learn More About
Knee Replacement Lawsuits
Design problems with several types of knee implants have resulted in lawsuits for individuals who experienced painful complications.
See If You Qualify For CompensationOVERVIEW: Although knee replacements are designed to last 15 to 20 years, problems have been linked to several different systems used in recent years, which may cause individuals to experiencing complications, such as:
- Severe Pain, Swelling and Loss of Mobility
- Knee Implant Failure or Loosening
- Revision Surgery
In many cases, it appears the manufacturers knew or were warned about these problems for years, yet withheld information from consumers and the medical community. As a result, financial compensation may be available through a knee replacement lawsuit. It is not necessary to know what type of an implant was used during your surgery, a product liability lawyer can help!
DEPUY SYNTHES ATTUNE KNEE LAWSUITS: The DePuy Attune Knee System was approved by the FDA in 2010 through the controversial 510(k) fast-track approval program, meaning that DePuy and it’s parent company, Johnson & Johnson, only had to prove that the device was “substantially equivalent” to existing implants. Since about March 2013, the DePuy Attune knee has been widely used by surgeons throughout the United States.
Although the DePuy Attune knee was marketed as an innovative design, which was designed to provide a better range of motion and stability among individuals doing every day activities, it has been linked to a higher-than-expected rate of problems and failure, often resulting in the need for revision surgery to remove the DePuy Attune knee and replace it with another device.
In many cases, the DePuy Attune failures have been linked to tibial baseplate loosening, after the cement bond failed between the tibial baseplate and the rest of the implant.
As of June 2017, the FDA has received about 1,400 reports of DePuy Attune Knee problems through its Manufacturer and User Facility Device Experience (MAUDE) system, which receives reports of adverse medical device reports from manufacturers, as well as importers and places where the devices are used. Of those 1,400 reports, 633 involved patients who had to undergo revision surgery to have the devices removed.
EXACTECH OPTETRAK KNEE SYSTEM PROBLEMS: Lawsuits over Exactech’s Optetrak Total Knee Replacement have also been filed, alleging design defects and problems.
Since about 2012, the FDA has received large numbers of adverse event reports involving Exactech Optetrack tibial loosening, pain, loss of mobility, swelling, and the need for revision surgery. Afterwards, the manufacturer removed a “finned” tibial tray design used with the implants and replaced them with a new design known as a “fit” tibial tray. Some have considered this a silent knee replacement recall, designed to prevent negative media coverage.
In October 2022, the U.S. Judicial Panel on Multidistrict Litigation ordered all Exactech recall lawsuits consolidated before one judge in the Eastern District of New York for pretrial proceedings. In December, the presiding judge appointed a number of Exactech implant lawyers to leadership positions in the consolidated litigation.
On March 23, 2023, the FDA issued an Exactech implant warning, urging doctors to monitor patients for signs of hip and knee replacement failure. The agency said those not experiencing problems did not need to seek revision surgery to have the devices removed.
As of August 2024, there are currently more than 1,600 product liability lawsuits filed against Exactech over problems linked to defective knee, hip and ankle components first pulled from the market in early 2022, due to “out-of-specification” vacuum sealed bags used with a plastic tibial insert component.
Given the number of Exactech lawsuits over defective implants brought throughout the federal court system by the end of 2022, centralized pretrial proceedings were established in the federal court system before U.S. District Judge Nicholas G. Garaufis in the Eastern District of New York, where the parties have selected a small group of representative claims to prepare for early bellwether trials set to begin between June 2025 and January 2026.
In an order issued in April 2024, the first two Exactech bellwether trials were scheduled to begin on June 2, 2025 and August 5, 2025, involving claims brought by Gayle Tarloff and Geraldine Larson, respectively. Both of these plaintiffs are from New York, and indicate they experienced problems with an Optetrak Logic knee implant, which is the product most commonly implicated in Exactech recall lawsuits.
However, after Exactech issued the April 2024 recall involving the patella knee component used during Tarloffs joint replacement surgery, the parties agreed to a scheduling change for the first Exactech trial dates to allow for additional time for discovery. As a result, on August 6, 2024, Judge Garaufis agreed to the scheduling change, changing the start of the Larson trial to June 2025, and pushing back the Tarloff trial until August 2025.
ARTHREX IBALANCE KNEE SYSTEM PROBLEMS: Since about 2014, problems with the Arthrex IBalance knee may have caused individuals to require removal of the implant, according to allegations raised in lawsuits.
In February 2016, an Arthrex iBalance recall was issued for some devices, indicating that the outer surface of the implants were smooth instead of textured, which could result in a failure to bond and, ultimately, implant failures.
A number of Arthrex IBalance knee problems have been linked to loosening, which has resulted in catastrophic implant failure.
KNEE REPLACEMENT INFECTION LAWSUITS: In addition to cases for unreasonably dangerous and defective knee implants, many individuals have experienced serious complications due to infections caused by the use of a 3M Bair Hugger warming system, which is commonly used during hip and knee replacement surgical procedures to help control body temperature.
The forced air warming system is found in many operating rooms nationwide, but may cause bacteria and contaminants to enter the sterile surgical site, leading to devastating deep joint infections, which typically require complex treatment.
The Bair Hugger warmer contains a portable heater/blower unit, with a flexible hose that is hooked up to a disposable blanket that is positioned over surgical patients. The forced air warming blanket is designed to deliver warm air onto a patient during an operation to keep the wound area and patient appropriately heated, which reduces the risk of bleeding and shortens recovery times.
According to allegations raised in Bair Hugger knee replacement infection lawsuits, the forced air warming device disrupts the laminar air flow in the operating room. As a result of the manufacturers’ failure to warn consumers and the medical community, cases are being pursued nationwide.
22 Comments
StevenJune 5, 2024 at 8:49 am
This original recap was put together back in 2012. We tried to file against DePuy several times over the years, but no one would take the case .. Recent events added to end ... We both used to be fairly active people. I’ve had horses since I was 5, we put in a garden every year, we own Dobermans and used to spend a lot of time hiking with them. The past five years, it has become increasing[Show More]This original recap was put together back in 2012. We tried to file against DePuy several times over the years, but no one would take the case .. Recent events added to end ... We both used to be fairly active people. I’ve had horses since I was 5, we put in a garden every year, we own Dobermans and used to spend a lot of time hiking with them. The past five years, it has become increasingly difficult for us to maintain this way of life, due to Steve’s issues with his knees. We have since given up on horse ownership, since he physically cannot help me maintain the barn and pasture and haul in hay and grain now, and it was too much for me to handle on my own. We did not put in a garden last year, but planted one this year, partially in raised beds so that he can work in it a little easier. I am hiking with the dogs with a friend these days, since he has a hard time just getting himself around right now. We have always been hardworking people, with both of us working two jobs most of our married life. I retired from my main job in June 2008 due to my Mom’s steadily declining health. I run a home based movie transfer business now. Steve has worked for 14 years at Pennsylvania Transformer in Canonsburg, PA. He used to work maintenance there, but as time went on could not physically do all of the grass mowing he was assigned, so he transferred to a position where he helps to build the transformers. He is on his feet on a concrete floor 8-10 hours a day. I detached a retina in August 2011 - tried fixing it with laser and a gas bubble, but it tore in a different spot two weeks later, requiring surgery, a scleral buckle, laser, and a gas bubble. I was on no lifting/bending/driving status until October 6, 2011. In January 2008, Steve was diagnosed with bone on bone osteoarthritis - no cartilage left. He tried natural supplements, cortisone shots, and HA injections to no avail. Finally in the second half of 2009 when he could hardly get up and down the steps to go to work, he decided it was time to see about knee replacements. We started out with an orthopedic surgeon in Canonsburg Hospital. We were talking with him about standard knee replacements. He said they usually last 10-12 years, depending on your level of activity. He said he didn’t really like to put them in at Steve’s age unless there are no other options, because when people are still active in their 50s, they will need them replaced again later in life. We told him we would think about it, and came home and did research on the web about replacement knees made for active people. We came across a website for DePuy Rotating Platform Knees, owned by Johnson & Johnson. They were supposed to be just what we were looking for - increased flexibility and range of motion, with an expected lifetime of 15-20 years. We looked up the closest surgeon who used this knee, and made an appointment at Steel Valley Orthopedics, 1200 Brooks Lane #240, Clairton, PA 15025 (412-469-1660). Jeffrey M. Matheny, M.D., was the doctor in their group who uses these knees. He tried a series of a different type of HA injections before they decided to replace the knees. Surgery was scheduled for January 5, 2010 to have both knees replaced. Other than having a reaction to Morphine, he did well with surgery and amazingly well with rehab. Got the OK to go back to work in April 2010. We started taking short hikes with the dogs again, put in a garden, we were back to barn work and feeling a little better about our lives. He followed the check up schedule from the doctor’s office, doing well at each checkup. He had an appointment for his checkup on Friday, October 7, 2011. Dr. Matheny checked him out, took X-rays, said he was doing “GREAT!” - he did not need to see him for two years. He said the swelling in his knee and leg was normal and would eventually go down. My Mom passed away on May 26, 2011 and left my parents’ house to us. We were in the process of moving in - Steve was helping me that weekend, and ended up in bed - thought he was catching a cold because he had a fever and chills. Stayed in bed most of the weekend. He got up at 3 AM on Monday, October 10, 2011, went to take a step and crashed to the floor. Called off work because he could not stand up. He would not let me call an ambulance, so with a lot of pain and effort we got him from the house into my vehicle and went to Jefferson Hospital ER. To this day I still have a hard time believing that infection did not show up in some way on the X-rays two days before this happened. He had a fever, and by this time his knee was majorly swollen and he had cellulitis in his lower leg. They admitted him and started treatment. The infection caused some issues with his heart function - he’s now on meds for it. His kidneys would not start functioning for days - he was just hours away from being started on dialysis for life when they decided to increase urine output again. It was eventually decided the knee had to come out since bloodwork showed a major strep infection throughout his body. They pulled the knee and put a concrete antibiotic spacer in his leg. He came home with a full leg brace, a non weight bearing status, on a walker, the non weight bearing status necessitating hopping on his left leg to get around. He only traveled to the bathroom next to the bedroom, then back to bed. They inserted a pic line, and between the visiting nurse who came several times a week and I, we cleaned the incision, changed the bandages, and administered IV antibiotics daily. He spent most of his time from mid-October to mid-January in bed. On January 19, 2012, after fluid cultures from the knee cavity showed there was no infection left after being off antibiotics for a couple of weeks, they took out the spacer and put in a standard DePuy knee, not a rotating platform knee. He rehabbed in the orthopedic wing at Jefferson, then came home and had a visiting physical therapist come in twice a week until released to go back to work. I broke my ankle on January 30, requiring a plate on one side and screws on the other, so there was no way for me to take him in for therapy at a rehab center. He got clearance to go back to work in April 2012, on light (seated) duty until released for full time work weeks later. Steve just kept plugging along, not walking well, but getting by. He was born with extremely flat feet, and has been wearing custom made orthotics in his shoes. Dr. Matheny gave him a prescription for new ones, based on the fact that one leg was shorter than the other after the revision surgery on his right knee. We went to De La Torre Orthotics, 575 Coal Valley Road, Jefferson Hills, PA 15025 (412-469-7482) and presented them with a prescription for new orthotics with a shim put in the heel of the shorter leg to balance him out and square up his gait. He wore these orthotics as prescribed for weeks, and was getting no relief. We went back to their office to find that they overlooked the part of the script that said they were to insert the shim. They added one, and we tried to move on. Still not walking any better - we went back and they adjusted the thickness of it, saying that was the best they could do and if he still had issues we should return to the surgeon. We went to see Dr. Matheny again on Friday, July 6, 2012; he did X-rays of both knees and told us the left Rotating Platform knee is “failing.” He said there are areas of the revision right knee that are pulling loose also and are going to have to be dealt with. He pulled fluid from both knees, and we dropped the samples off at their lab on the way out. He told us to come see him at his Bethel Park office on Monday, July 9, 2012. He said he was going to consult with his partners over this. We told him we do not want ANY type of DePuy knee put in with the left knee revision. Said the cultures were not showing any infection yet, which was a good sign, but to come back and see him at his Jefferson office on Friday, July 13, 2012. Told us the cultures were still negative, bloodwork was OK, but he still wasn’t convinced there is not infection in there because he can’t think of any other reason why the knee would be failing. When we questioned him about the right knee that he said is pulling loose in spots, he now told us that it is not an issue that needs to be dealt with right away, but we definitely have to keep an eye on it. He transferred our case to Edward D. Poon, M.D., in their group. He uses Zimmer knees, and is going to put in a standard knee on the left leg. Dr. Poon cannot see us until August 8, with surgery scheduled on August 13, 2012. We have done all of the pre surgery testing, and we go on Tuesday to see his PCP for clearance. Steve has been off work again since July 9, 2012, and is getting around slowly using a cane. He takes his temperature every day, so that we can get him to the hospital if it gets high, possibly due to an infection. In hindsight, we have been kicking ourselves for not just going with the standard knees at the start. In our quest to regain an active lifestyle for him, we have slid so far backwards that it feels like we’ll never get ahead of this. The amount of pain, worry and stress, not to mention financial stress, this has caused in our lives is just staggering. It will be almost three years since we started this process by the time he finishes rehab after this next surgery. We do not know if he will be able to return to work after this one - this will make four new knees in 2.5 years. Not sure if his body will be able to take standing on concrete all day long after this. We keep trying to take one day at a time, but it is truly hard some days. It feels like he just keeps falling through the cracks in the medical system. Update on April 24, 2023 ... He has had no comfort zone with his legs since the start of these surgical nightmares. We switched from Steel Valley Orthopedics last year to become part of Dr. Ari Pressman’s patient list at Uniontown Hospital. We have no faith in the doctors at Steel Valley Orthopedics and decided to move on from them. We’ve been going for yearly checkups with Dr. Pressman for the past couple of years. He says the one knee is starting to loosen, but does not want to do a third replacement unless absolutely necessary. Steve is still going to work, working with leg pain daily. He often gets frustrated over his state of health, saying he should have just kept his own knees and lived with the pain and lack of mobility. Update on June 5, 2024 - saw Dr. Pressman again yesterday, as pain level is increasing in left knee. He is concerned that it is in near danger of failing - sending us for pre surgery testing this week. Put him off work on short term disability. He can hardly walk with a cane right now. Does not think he’ll be returning to work after this third revision. We truly do not understand why Depuy is not compensating people for what they have done to their lives.
JohnDecember 4, 2023 at 1:25 pm
I had my knee replacement total knee last year at first was great about six months in started having swelling swelling lymph node in upper leg know one could explain why then started bleeding in my leg which was stated to be baker's cyst but bone scan should aseptic loosing and needs to be replaced
RebeccaMay 17, 2023 at 7:18 pm
Need legal advice before revision.
DianeDecember 13, 2022 at 9:24 pm
My first knee replacement was a nightmare. The pain and swelling made me unable to walk. I went to a specialist and got a revision after a manipulation. I was in a wheelchair for six months because I was nonweightbearing. It’s never been the same. After almost 3 years, I can barely walk on it without horrible pain. I had to quit my high-paying job which financially almost bankrupt and me. I now wo[Show More]My first knee replacement was a nightmare. The pain and swelling made me unable to walk. I went to a specialist and got a revision after a manipulation. I was in a wheelchair for six months because I was nonweightbearing. It’s never been the same. After almost 3 years, I can barely walk on it without horrible pain. I had to quit my high-paying job which financially almost bankrupt and me. I now work in an office and it’s very low paying.
IraJune 9, 2022 at 7:20 am
My knee hurt sometimes an when sitting it lets me know it’s there hurts like my real knee
VernonJune 1, 2022 at 5:50 pm
I am have experienced clucking, popping and constant pain in the knee with the replacement. I have had surgery twice on the same knee. I would like to speak with someone regarding this lawsuit.
SonjaJanuary 9, 2022 at 8:15 pm
Total knee replacement 12/2019 revision 12/2021 cement came lose.
BridgetSeptember 29, 2021 at 7:34 am
I had trkr on 8/5/2020 Swelling, pain non stop for 11 months.. I went for a 2nd opinion and his words were..The first Dr didn't take enough bone off for the implant.. It's only cementers but in knee replacements that's a lot... Revision done on 7/20/2021. Can I put a claim on the first Dr for a botched knee replacement surgery? For all the pain and suffering I went threw until I got the revision?
KellieNovember 13, 2020 at 5:39 pm
I had double knee replacement surgery in December 2014. I have complained since then asking if this loud noise was normal. The popping and clicking was audible to people across the room. After a fall I went to a doctor and he checked my knees. Both are super loose and basically floppy and super unstable, So no, the noise wasn’t normal. Last year I had revision surgery on the left knee. It[Show More]I had double knee replacement surgery in December 2014. I have complained since then asking if this loud noise was normal. The popping and clicking was audible to people across the room. After a fall I went to a doctor and he checked my knees. Both are super loose and basically floppy and super unstable, So no, the noise wasn’t normal. Last year I had revision surgery on the left knee. It had to be revised again this year and I’m recovering. It seems that revisions of revisions are super hard and my bones fractured during surgery. So now I am wheelchair bound for at least 8 weeks. This is so hard. I have a right knee that is extremely unstable and have to depend on it to support my body because of the non-weight bearing on the left. And after I recover from this I have to get the right knee revision done. NOBODY should have to go through this kind of ordeal. I am certainly looking for help in finding a remedy. I’m sick of being in recovery.
NancyOctober 1, 2020 at 1:54 pm
Feb 11,2019 I had total knee replacement on right knee.I completed therapy and compared myself to others having the same and always felt they were all doing much better on recovery than I. Each visit to the orthopedic Dr I would do complain and felt that they thought Iwas there for pills. By September the Dr sent me back to therapy. I completed the therapy and still had the unbearable pain.Havin[Show More]Feb 11,2019 I had total knee replacement on right knee.I completed therapy and compared myself to others having the same and always felt they were all doing much better on recovery than I. Each visit to the orthopedic Dr I would do complain and felt that they thought Iwas there for pills. By September the Dr sent me back to therapy. I completed the therapy and still had the unbearable pain.Having had shots and nothing helping I know itwas only a year but something was clearly wrong and nothing was helping .It was a long year. The Dr ordered xrays saying it looked good and finally ordered a bone scan and was scheduled for revision knee replacement in March. Due to pandemic it was cancelled until June 15 2020. My revision surgery has been so tough on me and the pain and instability and so much therapy and constant fear of falling.All because something came loose and in such a short period of time.
DonnaApril 9, 2020 at 12:45 am
Pls try to call 3 year after my tkr and a back surgery doc said it was in my back ,so many trips to the er for blood clots and a spacer in my knee and all the pain and I still don’t have a knee
DawnJanuary 22, 2020 at 1:35 am
I have had two knee Replacements 2015-2019 after having total reconstructions in 1984 and 1986 I feel as though these in plants are failed because my knees have been in nothing but severe pain swelling there's hot to the touch and I have problem walking standing up off of the toilet is all very very painful
KevinJanuary 8, 2020 at 3:29 pm
I had a total knee replacement February 13th 2018 my knee stay swollen months after the surgery until now January 2020 it pops snap it burns and hurts all the time the plate on the table off has come loose the doctor said on his way to fix it it's for another surgery I can't walk or stand for long periods of time kneel down don't even know if I can hold another job been out of work since April 17t[Show More]I had a total knee replacement February 13th 2018 my knee stay swollen months after the surgery until now January 2020 it pops snap it burns and hurts all the time the plate on the table off has come loose the doctor said on his way to fix it it's for another surgery I can't walk or stand for long periods of time kneel down don't even know if I can hold another job been out of work since April 17th of 2018 with no help I'm not going to take a bunch of opioids for the pain and the burning in the knee I have no insurance can't afford no insurance I have no disability insurance oh nothing I don't know how I'm going to get the surgery that's supposed to be on February 6th 2020 I just need help
TinaDecember 4, 2019 at 4:35 pm
I had total knee replacement 2/2/16 . I had pain swelling etc. I reasonably foun d a orthopedic that takes my insurance.
ToniFebruary 28, 2019 at 6:08 am
I had a knee replacement Nov.16,2016.I started having problems out of my knee in Sept.2018 I started claiming to my arthritis doctor about pain in my knee and it trying to give out on me.She checked it and it was real swollen she suggested I contact my orthopaedic doctor.I called and got an appointment because I got were my leg hurt all the time and I began to have problems walking without a cane,[Show More]I had a knee replacement Nov.16,2016.I started having problems out of my knee in Sept.2018 I started claiming to my arthritis doctor about pain in my knee and it trying to give out on me.She checked it and it was real swollen she suggested I contact my orthopaedic doctor.I called and got an appointment because I got were my leg hurt all the time and I began to have problems walking without a cane, with in a matter of a few weeks I had to advance to a walker to have stability, I was losing my balance because of my leg being so weak.I went to the ortho doctor and he did a bone scan and it showed my knee was separated from the tubal.It was broken apart and it could only be repeated was with surgery.So I had a revised knee replacement surgery on Jan.3 ,2019.I went through a lot of pain for about three months with no pain medication because of other people abusing pain meds. I was punished by my insurance company and denied my prescription even though I was not an a drug abuser.So I suffered for 3 months until the surgery.My surgeon said he does not no how I was even walking because the bone was completely broke a loose just dangling in there.
EvelynAugust 12, 2018 at 12:10 am
I had my knee replaced in 12/2015. Since I had it replaced I have nothing but pain. I have a huge knot on my leg that continues to get larger and the entire knee feels stiff and swollen. I sought a second opinion from another doctor but he won’t touch it it. Says the risk of infection from removing and replacing it with a different brand out weighs the pain I suffer from on a daily basis.
ronAugust 2, 2018 at 10:49 pm
I had my right knee replaced on 5-12-2014 and my left on 4-2-15, My right is starting to swell and severe pain on the right side, I go to see the surgeon on 8-7-2018, I have been living on pain pills for the last,week had to cancel one appointment due to family emergency. I hope the left does not give the same trouble
WilliamJuly 24, 2018 at 9:59 am
I am on my 4th knee replacement. In 2011 I took a few weeks off work for what was sapose to be quick. Due to infection, in plant failures, loosening, pain, I a have had so many revisions surgery's. Scrapings many hospital stays, months off pick line antibiotics, no knee on and on I live in pain twenty four sev I can hardly walk No income since, 2011
SandraJuly 17, 2018 at 7:31 pm
I had knee replacement surgery in January of 2013. I was in pain every day. I could not get another orthopedic surgeon to even look at my knee. The doctor that did my surgery gave me shots, ordered physical therapy, tried draining fluid, did everything. Nothing helped. Finally got another doctor to see me. The wrong knee had been put in. He took out all the old metal and replaced the complete knee[Show More]I had knee replacement surgery in January of 2013. I was in pain every day. I could not get another orthopedic surgeon to even look at my knee. The doctor that did my surgery gave me shots, ordered physical therapy, tried draining fluid, did everything. Nothing helped. Finally got another doctor to see me. The wrong knee had been put in. He took out all the old metal and replaced the complete knee. I am finally getting some relief.
MichaelMarch 12, 2018 at 11:50 pm
In 2007 I had a total knee replacement on my left knee,after said knee was replaced I informed the Doctor several months after the surgery that there was a large mass on my knee he advised that it was normal,for the last several years my knee has begun to give me more issues,its swelling to the point that I'm unable to bend it or walk without support.I have constant pain with the knee which goes d[Show More]In 2007 I had a total knee replacement on my left knee,after said knee was replaced I informed the Doctor several months after the surgery that there was a large mass on my knee he advised that it was normal,for the last several years my knee has begun to give me more issues,its swelling to the point that I'm unable to bend it or walk without support.I have constant pain with the knee which goes down my leg to my feet.
JaniceNovember 19, 2017 at 6:26 pm
Revision surgery
bernardOctober 18, 2017 at 4:36 pm
The research shows that johnson and johnson was aware of future problems with some of its knee replacement units..the next round of suits will prob. be the depuy lcs units.and down the line.more parts and total units. i raise the question did the dr s know through the f.d.a warnings and johnson and johnson and its other co.s statements including the need for polishing etc.on its lcs unit this rai[Show More]The research shows that johnson and johnson was aware of future problems with some of its knee replacement units..the next round of suits will prob. be the depuy lcs units.and down the line.more parts and total units. i raise the question did the dr s know through the f.d.a warnings and johnson and johnson and its other co.s statements including the need for polishing etc.on its lcs unit this raises the question--- the dr s should have informed their patients on any notice involving the questioned knee units.yes or no