Vision Loss from Cobalt Poisoning of the Eye from MoM Hip Replacement

Title: Cobalt-Chromium Metallosis With Normal Electroretinogram

Background:

The popularity of Metal-on-Metal (MoM) hip implants, which are typically made out of cobalt and chromium, has made cobalt poisoning of the eye more common. This condition is called ocular cobalt toxicity. This study focuses on a 66-year-old-man whose vision was damaged because he got cobalt poisoning from a MoM hip implant. The authors tried to determine if his vision loss was caused by damage to the optic nerve, the retina, or both.

Methods:

The authors used multiple types of eye exams, including the Humphrey Visual Field (VF) exam, an electroretinogram (ERG), a multifocal electroretinogram (mfERG), multifocal visual evoked potentials (mfVEP), and an optical coherence tomography (OCT) scan.

Results:

The patient had blurred vision, poor color vision, and a type of abnormal blind spot called cecocentral scotoma. Because he had problems with his right eye since childhood, only the test results from his left eye were considered in the study. His ERG results were normal, his mfERG results were normal, and his mfVEP results were normal. However, his mfVEP exam showed a type of visual malfunction called decreased central amplitudes. The OCT scans also appeared to be fully normal.

Conclusion:

Decreased color vision and blind spots are indicators of nerve damage caused by chemical poisoning. Additionally, decreased central amplitudes are also a sign of nerve damage due to chemical poisoning. Therefore, the doctors believe the patient had an early stage of optic nerve poisoning that could not yet be detected by looking at the retina through an OCT scan.

Introduction:

It is not yet known how exactly a failed MoM implant causes eye damage. Cobalt and chromium leak into the bloodstream and the tissue surrounding the implant, causing high levels of metal in the blood. Typically, within 2 years, these patients develop hearing loss, visual loss, hypothyroidism, and heart disease.

Among other visual impairments, patients with cobalt poisoning have experienced damage to the optic nerve and problems with blood flow in the retina. Additionally, these patients’ ERGs usually yield abnormal results. An ERG is an eye exam that measures how the retina responds to light stimulation.

Case Report:

A 66-year-old man received a ceramic-on-ceramic hip replacement. Three years later, his implant broke and was replaced with a metal on metal hip. Nine months later, he realized that traffic lights looked orange to him. He had a hard time seeing at a distance and close-up, and he had to get a hearing aid. He also had swelling in his abdomen, ankle swelling, left hip pain, pale diarrhea, a rash, poor coordination, and a loss of mental clarity.

One year after his revision surgery, vision in his left eye was 20/30. He could not correctly identify any colors, but a funduscopy (an examination of the inner structure of the eye) showed that everything about his physical eye structure was normal.

Many tests and scans were performed on the patient. OCT and ERG scans all showed normal results. However, the mfVEP exam showed a type of visual impairment called central depression of amplitudes. Testing of his visual field showed another type of visual impairment called cecocentral depression.

The patient’s cobalt levels in his blood were 1,078 μg/L; acceptable levels are less than .3 μg/L. He received another revision surgery for his hip implant because he evidently had cobalt poisoning. During surgery, the doctors found ceramic fragments in his joints, and there was significant wear on the implant. The cobalt levels around his joint were above the maximum recordable level of 1,000.0 μg/L.

Following this revision surgery, the patient’s cobalt levels got progressively lower, and his vision continually improved until going back to normal.

Discussion:

This case is different from other reports of cobalt toxicity in the retina. In other cases, abnormalities were detected in the ERG scans. However, this patient had normal ERG and OCT results.

It is unclear whether the patient’s problem was fundamentally caused by the retina or the optic nerve. It is possible that the patient was experiencing poisoning of his retina that could not yet be detected by ERG scans. On the other hand, some of his symptoms suggest that his optic nerve was damaged due to cobalt poisoning.

In conclusion, the authors believe they may have detected a type of optic nerve poisoning that could not yet be physically detected on an OCT scan. Therefore, just because a patient with a metal on metal hip implant has normal ERG results does not mean he or she does not have cobalt poisoning, especially when other symptoms are present. Other symptoms to look out for include ringing in the ears (tinnitus), deafness, poor coordination, depression, heart failure, and hypothyroidism. It is important that eye doctors perform various types of tests and scans on patients with suspected cobalt poisoning.

Reference

Grillo, L., Nguyen, H., Tsang, S., Hood, D., Odel, J. Journal of Neuro-Opthalmology 2016;36:383-388.

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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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Continue Reading Vision Loss from Cobalt Poisoning of the Eye from MoM Hip Replacement

Check for Metal Hip Issues if Patient has Cobalt-Related Heart Concern

Title: Unusual Case of Congestive Heart Failure:  Cardiac Magnetic Resonance Imaging and Histopathologic Findings in Cobalt Cardiomyopathy

Summary

A 69-year-old woman came to the authors with symptoms of congestive heart failure, a heart condition that leads to buildups of fluid in the lungs. She had a history of hypertension, mild kidney problems, and hip replacements on both hips. An ultrasound showed her heart’s left ventricle was pumping blood at a rate of 25% to 30% (a normal rate is 55% or higher). The left ventricle is a chamber in the heart responsible for pumping most of our blood. The ultrasound also revealed some fluid around the patient’s heart. Doctors tested the fluid and found no infection or malignant cells.

Over the next four months, the patient’s heart function declined rapidly, leading to many hospitalizations for congestive heart failure and low blood pressure.

An MRI of her heart revealed that her left ventricle had a normal size and thickness, but it was pumping blood at a severely low rate (14%). Her right ventricle was also a normal size, but it was also not pumping blood adequately. Several areas of her heart (specifically, the subepicardial lateral walls, left atrial wall and the right atrial wall) were enlarged.

The patient mentioned that her Depuy metal on metal hip implant had been squeaking for two years and that she planned to have it removed because it had been recalled. She had high cobalt and chromium levels in her blood.

Because of the concerning heart images and her high cobalt and chromium levels, the doctors performed what is called a right-heart catheterization, an operation where a small tube is inserted into the right side of the heart. This tube then carries blood to the lungs. The doctors also tested a sample of her heart tissue.

Lab tests found that the cells of her heart muscles were enlarged and had some scarring and inflammation. They also found symptoms of dilated cardiomyopathy (DCM), a condition where the heart’s ability to pump blood is decreased because the left ventricle is enlarged and weakened, probably because of the patient’s high cobalt levels. Additionally, they found signs of cobalt cardiomyopathy, a type of heart disease caused by cobalt poisoning. However, the levels of cobalt in the patient’s heart muscles could not be obtained.

The patient’s condition then deteriorated until she went into cardiogenic shock, a condition where the heart cannot pump enough blood to meet the body’s needs. She had to receive advanced heart failure support, have her hip implant removed, and was diagnosed with cobalt-caused heart disease. After having her metal-on-metal (MoM) hip implant replaced with a ceramic implant, she had a stroke and died.

Recently, there have been many reports of cobalt-caused heart disease due to MoM hip implants failing. When this occurs, the heart disease can usually be reversed by removing the hip implant.

Other reports of cobalt-caused heart disease have shown similar heart malfunction symptoms, such as the buildup of fluid around the heart and decreased blood-pumping ability.

Conclusion

The authors feel that fluid around the heart and significant inflammation of the heart walls might indicate cobalt-caused heart disease in future cases. Thus, the authors suggest that, when cobalt-caused cardiomyopathy is suspected, doctors should find out what kind of MoM implant the patient has, test the cobalt levels in the patient’s blood, perform heart ultrasounds and MRIs, and also test the cobalt levels of the heart muscles if possible.

Reference

Khan, A., Verma, R., Bajpai, A.,, Mackey-Bojack, S. Circ Cardiovas Imaging. 2015;8: doi: 10.1161/CIRCIMAGING.115.003352

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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Cobalt Toxicity from Metal Hip Causes Vision Damage

Title: Hip ­Implant Related Chorio-­Retinal Cobalt Toxicity

Abstract

A 39-year-old female with high levels of cobalt in her blood (a side-effect of her two hip implants) came to the doctors with complaints that her left eye had been blurry for three weeks. Eye imaging revealed that the light-sensitive portion of the patient’s retina (called the photoreceptor-RPE complex) was degenerating.

The authors believe this patient experienced damage to the choroid region of her retina due to cobalt poisoning from her hip implants; this is a condition called implant-related chorio-retinal cobalt toxicity.

Introduction

Cobalt poisoning is rare, but it has become more common due to the high number of people opting for Metal-on-Metal hip replacement implants. These implants can increase levels of cobalt in the blood to toxic levels. Many health problems, including vision loss, have been associated with elevated cobalt levels in the blood. However, the doctors believe this is the first time a human’s retina has been damaged due to implant-caused cobalt poisoning.

Case Report

The patient received the ASR™ Hip System implant in each of her hips. She replaced one hip 2 years prior to coming to the doctors and the other 5 years prior. She complained of having blurry vision in her left eye and discomfort in both of her eyes for 3 weeks. She also sometimes experienced a metallic taste in her mouth and nausea in the morning. She had a normal medical history. Her brand of implants had recently been recalled because of its high rate of failure.

The patient had 20/16 vision and normal fluid pressure inside both of her eyes. The front-most part of her eyes (called the anterior) appeared normal, as did the interior back wall of her eyes (called the fundi). However, an optical coherence tomography (OCT) scan revealed several lesions in the patient’s retina. The lesions were located in a portion of the retina called the RPE complex and the photoreceptors, which are the parts of the eye that are sensitive to light. Additionally, eye imaging showed the patient’s macula – an oval-shaped area near the center of the retina – was thicker than normal.

Multiple types of technology-aided eye exams, called electrophysiology tests, were performed on the patient. Almost all of the electrophysiology tests yielded normal results for both eyes.

However, while the Arden index for the right eye was normal at 2.9, the Arden index for the left eye was just borderline normal at 1.9. The Arden index measures the ratio of light and dark sensed by the eye. A score lower than 1.8 is indicative of an eye malfunction.

Lab tests showed high levels of cobalt and chromium in the patient’s blood. Normal cobalt levels are between 0 and 20 nmol/L, but the patient’s cobalt levels were at 757 nmol/L. Normal chromium levels are between 10 and 200 nmol/L, but the patient’s chromium levels were at 595 nmol/L.

The doctors diagnosed the patient with chorio-retinal degeneration, which occurs when the choroid region of the retina has been damaged. They attributed the cause to the toxic levels of cobalt in the patient’s blood, which were caused by her hip implants.

The patient was advised to monitor her eyesight, and she had two follow-up appointments where no new damage was noted. The patient’s orthopedic surgeon found that her implants were well-functioning, and her cobalt and chromium levels did not increase or decrease. Because the patient has not gotten worse, revision surgery has not yet been considered necessary.

Discussion

The retina requires a large amount of oxygen in order to function. The choroid region of the retina is responsible for supplying most of the oxygen-filled blood to the retina. So a lack of blood in the choroid region will lead to a lack of oxygen in the retina, causing damage to the parts of the retina that are sensitive to light; these are called photoreceptors.

When there is an excess of cobalt in the bloodstream, it is as if the retina’s oxygen supply is diminished. Therefore, the authors believe high cobalt levels in humans damage the photoreceptors in the retina. This pattern has been observed in several animal studies.

OCT scans showed the patient’s photoreceptor-RPE complex was damaged. Additionally, another kind of eye imaging called ICG angiography suggested that the choroid region of the patient’s eye had a diminished blood supply. Examinations showed the photoreceptors in the left eye were more damaged and dysfunctional than those in the right eye.

Blood can pass through the choroids of different eyes at different rates, which may explain why the patient only experienced problems with her left eye. Cases where patients experience problems with only one eye have been observed in instances of lead poisoning.

The doctors believe this is the first case where an implant led to cobalt poisoning and caused damage to the retina.

Reference

Ng S. Ebneter A, Gilhotra J. “Hip-Implant Related Chorio-Retinal Cobalt Toxicity,” Indian J Ophthalmol. 2013 Jan: 61(1): 35–37.

Read the Original Research Here

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.

Continue Reading Cobalt Toxicity from Metal Hip Causes Vision Damage

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