Metal Hips Cause Levels 26x Cobalt Increase and 15x Chromium Increase

Title: The Effect of Different Bearing Surfaces on Metal Ion Levels in Urine Following 28mm Metal-on-Metal and 28mm Metal-on-Polyethylene Total Hip Arthroplasty

Abstract

Total hip arthroplasty (THA), or hip replacement surgery, is known to increase levels of metal ions in the body. This is because the implant devices can shed metal particles into the body. This can have many negative effects on THA patients.

One way to measure the levels of metal ions in the body is to test patients’ urine. This study compares two different types of THA devices to see which one produces higher metal ion levels, as measured by patients’ urine. The two types of implants they compare are metal-on-metal (MoM) bearings and metal-on-polyethylene (MoP) bearings.

This study looks at 92 hip replacement patients; some of them had MoM implants and others had MoP implants. It measures the amount of cobalt, chromium, and molybdenum ions in their urine one year after getting their implants and two years post-surgery.

The patients with MoP implants had only a slight increase in cobalt and chromium levels two years post-surgery. For the patients with MoM devices, chromium levels were 15 times greater two years after surgery, and cobalt levels had increased by 26 times.

The authors conclude MoM devices cause very high cobalt and chromium levels; they are higher than those allowed for on-the-job exposure in Finland, where this study was conducted.

Introduction

Metal-on-metal hip implant devices that are made out of cobalt and chromium became really popular because they were thought to be more durable. Many improvements have been made since the first generation of MoM devices came out in the 1970s. However, there are still many health problems associated with these devices, such as adverse reaction to metal debris (ARMD). ARMD is a type of hip implant failure that results in pseudotumors and fluid collections around the hip implant. ARMD is caused by metal particles rubbing off of the implant device and into the body.

Patients and Methods

92 patients were divided into two groups, those who had hip replacements with MoM implants and those who had MoP implants. All of the patients had Biomet hip implants with 28-mm head diameters.

The authors collected urine samples from the patients before their hip replacement surgery, one-year post-surgery, and two years post-surgery.

Results

X-rays taken two years after surgery showed that none of the patients’ implants had moved or been misplaced since surgery. Only 5 implants had fractured, and they were fixed.

Before hip replacement surgery, average chromium levels for both MoM and MoP patients were less than .01 µmol/L. One year after surgery, average chromium levels had risen to .12 µmol/L for MoM patients but were still .01 µmol/L for MoP patients. Two years after surgery, average chromium levels rose to .15 µmol/L for MoM patients and .02 µmol/L for MoP patients. Essentially, chromium levels increased a lot more for MoM patients than they did for patients with MoP devices.

Average cobalt levels before hip replacement surgery were 21 nmol/L for MoM patients and 19 nmol/L for MoP patients. One year after surgery, average cobalt levels had risen to 417 nmol/L for MoM patients but only 33 nmol/L for MoP patients. Two years after surgery, cobalt levels had risen to 538 nmol/L for MoM patients and 57 for MoP patients. In sum, cobalt levels were dramatically higher for MoM patients than they were for MoP patients.

Molybdenum levels were also measured for all patients, but there were no significant changes in molybdenum levels.

Overall there was a much greater increase in cobalt and chromium levels for MoM patients than there was for MoP patients. Cobalt and chromium levels for MoM patients ended up being much higher than what is considered safe in Finland.

Discussion

The authors found that 28-mm MoM bearings in THA patients yield chromium and cobalt concentrations in urine that are higher than those recommended for workplace exposure.

The authors used urine samples because metal ion levels in urine are a good indicator of the levels of metal ions in the entire body.

Although cobalt is necessary for the body, excessive amounts of it can cause goiter and heart failure.

Ever since MoM implants were introduced, there have been concerns about their possible link to cancer; in animal studies, high levels of cobalt and chromium particles produced cancer cells in the animals. Recent studies have also suggested that hip implants (MoM and non-MoM) can cause changes to patients’ DNA and chromosomes.

There is also concern about the effects that MoM implants could have on the fetuses of patients who become pregnant because cobalt and chromium can cross the placenta; this could cause developmental problems in fetuses.

In theory, people who have THA surgery should face higher metal ion levels than people who receive hip resurfacing (HRA) surgery. However, the studies on this subject show conflicting results. One study showed that cobalt and chromium levels for patients who received HRA were higher than those who got THA surgery.

Another study found that cobalt and chromium levels in HRA patients and small-diameter head THA patients were significantly higher than in large-diameter head THA patients 6 months after surgery. However, this same study found that one-year post-surgery, all of the patients’ cobalt and chromium levels were more or less the same.

Some studies have shown that MoM implants often wear down very quickly in the first one to two years after surgery. After this initial period, they enter what the authors call a “steady-state” of wear for many years, which means the implants shed metal particles at a much lower rate.

MoP devices seem to be safer than MoM devices when it comes to metal ion levels.

**It is important to note that this study was funded and sponsored by Biomet UK Limited, a company that manufactures MoM devices.

Reference

Tiusanen, H., Makela, K., Kiilunen, M., Sarantsin, P., Sipola, E., Pesola, M. Scandinavian Journal of Surgery 102: 197-203, 2013.

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Our attorneys have sued almost all of the manufacturers in the orthopedic industry. In fact, our firm filed the FIRST metal-on-metal hip lawsuit in the United States.

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Metal on Metal Hips Linked to Early Onset Dementia and Depression

Title: “Neuropsychiatric symptoms following metal-on-metal implant failure with cobalt and chromium toxicity”

Abstract

Many metal-on-metal (MoM) total hip replacement implants have been recalled due to high failure rates. This study assesses the mental health of 10 patients who underwent revision surgery for failed MoM implants. The authors believe this is the first study to find a correlation between mental health complications and implant-caused cobalt and chromium poisoning.

Before undergoing revision surgery, 9 patients had toxic levels of chromium and cobalt in their blood. The authors diagnosed all 9 patients with depression; 3 of them were already being treated for depression. 7 out of 9 patients showed short-term memory loss and possible dementia.

The authors found a high incidence of cognitive disability and depression among patients who suffered from implant-caused metal poisoning (metallosis).

Background

MoM implants, which have a metal ball and socket, have been very popular in total hip replacement and hip resurfacing surgeries. When the components of MoM implants rub together over time, they release metal debris into patients’ bodies; this can lead to cobalt and chromium metal poisoning and require patients to undergo revision surgery.

High cobalt and chromium levels in the blood have been known to damage the way that visual stimulation is transmitted to the brain, among other disastrous effects.

Neurological problems, such as changes in brain structure and function, have been associated with high levels of cobalt and chromium in the blood following MoM hip replacement surgery.

Although some papers describe the physical effects of implant-caused cobalt and chromium poisoning, the authors believe this is the first paper to carefully describe the psychiatric problems associated with MoM implants.

Methods

This study looked at patients who received their original MoM implants between 2005 and 2009. All 10 patients underwent revision surgeries between 2008 and 2012 and were assessed for mental health in 2014 and 2015.

All patients received DePuy ASR hip implants; specifically, they received the acetabular implant, the taper sleeve adaptor, and unipolar femoral implants.

Patients’ brain function (or cognition) was evaluated using the Mini-Mental State Examination (MMSE) questionnaire. This exam gives a maximum score of 30, and most people up to age 85 have an average score of 28. A score of 25 or less in patients aged over 65 indicates cognitive disability and possible dementia.

Patients’ moods were evaluated using a questionnaire called the Beck Depression Inventory (BDI). A BDI score above 12 is high enough to diagnose depression.

The patients’ average age was 60.5 years. Six patients were female, four were male. On average, patients received the implants at age 52.5 and had them for an average of 4.44 years before undergoing revision.

Results

Observed metallosis:  Nine patients’ bloodwork was analyzed prior to undergoing revision surgery, and they all had toxic levels of cobalt and chromium in their blood. Their average chromium levels were 338 nmol/l; normal chromium levels are below 134.5 nmol/l. Their average cobalt levels were 669.4 nmol/l; normal cobalt levels are below 119 nmol/l.

The authors received the post-revision surgery bloodwork for only 3 patients. Two of these patients had acceptable metal levels in their blood. One patient still had toxic metal levels in his blood; his cobalt levels were normal, but his chromium levels were still high at 173 nmol/l.

Observed mood and cognitive function: The patients had moderately severe depression with an average BDI score of 27.6. Such high rates of depression are unusual.

There were significant cognitive abnormalities among the patients; their average MMSE score was 24.2. Seven out of 10 patients had short-term memory loss. This means that 70% of the patients showed signs of early-onset dementia, which is extremely unusual because only .00081% of the general population suffers from early-onset dementia. Additionally, some patients suffered from disorientation, concentration issues, and difficulty finding words.

The patient with the highest pre-revision surgery levels of chromium (664 nmol/l) and cobalt (2470 nmol/l) had the lowest MMSE score.

Patient vignettes: The authors provide more detail on 4 of the 9 patients, who will be referred to as Ms. X, Mr. Y, Mrs. Z, and Mrs. A.

Ms. X felt anxious, guilty, was tearful, had an unstable mood, and had a lowered self-esteem. She had a perfect dementia score (30), but a very high depression score (33) even though she was being treated for depression.

Mr. Y complained of social withdrawal, poor concentration, memory loss, and increased irritability, among other problems. His dementia score was lower than average (26), and his depression score was also very high (30) even after being treated for depression.

Mrs. Z complained of low mood, emotional instability, forgetfulness, a tendency to repeat herself, and inability to feel pleasure, among many other things. She was disoriented in person. She had a very low dementia score (17) and a significantly high depression score (38) even after being treated for depression.

Mrs. A had the highest pre-revision surgery metal levels (664 nmol/l of chromium and 2470 nmol/l of cobalt). She complained of chronic pain, low mood, low self-confidence, difficulty recalling words, inability to feel pleasure, and anxiety, among other things. She was unable to spell the word “world” backwards. She had significant cognitive abnormalities, a very low dementia score (18) and a very high depression score (33).

Discussion

This study finds a strong connection between depression, cognitive problems, and cobalt and chromium poisoning following a failed MoM implant.

Depression might be caused by the psychological impact of undergoing revision. Patients frequently reported fear of the need for further surgery and insecurity about pain and mobility.

Chromium and cobalt toxicity may have caused permanent but unchanging brain damage in the patients, which in turn may have caused the cognitive problems. Alternatively, metal poisoning may have triggered early onset dementia in these patients.

Conclusions

All doctors should assess the mental health of patients who received metal on metal implants. Additionally, patients who show signs of cognitive impairment should have their chromium and cobalt levels tested.

The authors urge that patients undergo revision surgery immediately after metal poisoning is detected, as this is the only way to fix elevated cobalt and chromium levels.

This study’s findings suggest that, in the future, patients with metal on metal implants might require care for dementia. The authors recognize that public safety is jeopardized by MoM implants.

Reference

Green et al. BMC Psychiatry (2017) 17:33.

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Our attorneys have sued almost all of the manufacturers in the orthopedic industry. In fact, our firm filed the FIRST metal-on-metal hip lawsuit in the United States.

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Pseudotumor in a Patient with a Biomet Hip Implant

Research Title: Pseudotumor in Large-Diameter Metal-on-Metal Total Hip Articulation

Abstract

This case study focuses on a patient who experienced pain in her hip following a large-diameter metal-on-metal (MoM) hip replacement. She also developed a pseudotumor, which is an abnormal swelling of tissue that resembles a tumor.

Intro

MoM hip implants are thought to be more stable and durable than metal-on-plastic implants, so they’ve become a popular choice for patients undergoing total hip replacement or hip resurfacing surgery in the United States.

However, MoM implants can cause conditions like an adverse reaction to metal debris (ARMD) and metallosis. ARMD is a form of implant failure that happens when the device sheds metal debris and causes negative effects like pseudotumors and collections of fluid around the implant. Metallosis is a type of metal poisoning that occurs when the implant’s metal debris raises the amount of metal in a patient’s blood.

This patient developed a pseudotumor five months after receiving a Biomet Magnum device with the Taperloc femoral stem. Her complications have been observed in other cases.

Case Report

A 39-year-old woman came to the authors with a 2-year history of hip pain. She had previously experienced bone tissue death in her left femur (a condition called avascular necrosis) but did not have any other medical problems. Prior to developing avascular necrosis, she was very physically active. She underwent total hip replacement surgery and received a Biomet Magnum device with the Taperloc femoral stem.

Right after her surgery, she made a full recovery, reported no pain, had full strength in her hip, and had a full range of motion in her hip. Three months after surgery, she began to feel pain in her left leg. Four months after surgery, she felt squeaking and popping in her hip.

Five months after surgery, she had such severe pain in her left hip, groin, and buttocks that she used crutches and could not go to work. She had swelling in her left hip and thigh. Her hip was weak and had impaired mobility. X-Rays revealed that her implant was not loose and had not moved. Her device’s femoral stem had an angle of 11.3 degrees, and the shell had an angle of 9.7 degrees. Blood tests indicated that she was experiencing inflammation but no infection.

The doctors took a sample of fluid from her left hip and found a liquid that looked like coconut milk with some yellow grains in it, but it had no signs of infection. Analysis showed that the fluid had chromium levels of 707.6 μg/L of chromium, titanium levels of 60 μg/L, and cobalt levels of 1068 μg/L. These levels are much higher than what is considered acceptable or healthy.

The patient underwent revision surgery because of these unusual and painful symptoms. During the surgery, doctors found a pseudotumor surrounding the implant and removed it. The doctors also found a type of dead tissue that resembled cheese. This tissue was sent for analysis but showed no sign of infection. Another tissue sample appeared to have an impaired blood supply and scarring. An analysis of the tissue surrounding the implant also showed impaired blood supply and scarring.

The patient received a metal-on-plastic implant during revision. The components were the Converge titanium acetabular shell, the Durasul Polyethylene insert, and the Biomet head. Two years after revision surgery, the patient had no negative symptoms other than occasional severe sharp pain in her left hip groin.

Discussion

This patient’s Biomet implant failed because of its metal on metal bearing surface. The levels of chromium and cobalt in the fluid surrounding her hip joint were extremely high.

Pseudotumors are caused by implants shedding metal debris into patients’ bodies as they wear down. The release of metal debris might be related to the positioning of the implant’s components, implant devices rubbing together abnormally, the types of metal in the implant, the thickness of the implant components, and other factors.

The doctors believe the device failed because the femoral neck of the implant was excessively rotated forward (21 degrees). They believe this positioning caused the implant to wear down rapidly and shed metal particles.

This patient’s chromium levels were 18 times higher than the average measurements of other reports, and her cobalt levels were 13 times higher.

One of the authors has stopped using large-diameter MoM implants as his go-to device for hip replacement patients because he has seen way too many complications from the implants. The author has had to revise 25 implants because the implants failed to attach to the patients’ bone and caused the patients severe pain. None of the implants the author has given have dislocated. The author now only uses one brand of implant for MoM hip replacements because he has not experienced any complications with it.

Doctors need to monitor MoM implant patients very carefully, and they need to be very mindful of the way they position the implant because it can mean the difference between failure and success. Additionally, cup inclination should not exceed 50 degrees sideways and 20 degrees forward. The author also believes that large-diameter MoM hip replacement could still be used to treat degenerative hip diseases, but doctors must be very mindful of their implant choice and surgical techniques to prevent failure.

Reference

Shahrdar, C. The Journal of Arthroplasty, Vol. 26 No. 4 2011.

Want to Discuss Your Metal on Metal Hip Case?

Maglio Christopher and Toale, P.A. is a national leader in metal on metal hip lawsuits. We have contacts within the orthopedic community and extensive medical and technical knowledge about these defective orthopedic hip replacements.

Our attorneys have sued almost all of the manufacturers in the orthopedic industry. In fact, our firm filed the FIRST metal-on-metal hip lawsuit in the United States.

Contact us at 888-952-5242 or fill out the online form below. Our Firm will review your information to determine if we can represent you.  We might even be able to review some of your medical information over the phone.

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