Truth: Due to the large volume of joint replacement surgeries, high-viscosity bone cement is often used to cut down on waiting time. In some cases, the higher viscosity can produce a weaker bond.
Truth: Bone cement can be a carcinogen and an irritant, potentially causing thermal necrosis during the setting process.
Truth: Incorrectly applied or mixed bone cement can fail to bond with either the prosthesis or the bone, which can cause joint pain and immobility.
If you have experienced any complications or side effects from bone cement, our team of highly-qualified lawyers is here to help you get the justice you deserve, with no charge unless the case is successful. Contact us now.
What Is Bone Cement?
Bone cement was first used in surgery in the 1940s to close gaps in the human skull and began to be used in the 1950s to anchor prosthetics. Every year, almost half of all joint replacement surgeries, numbering in the millions, have involved bone cement. The percentage of procedures using bone cement increases all the time.
Bone cement is supplied as both a powder and a liquid that must be mixed together in order to be used in surgery. The thickness of the mixture can vary depending on how it is mixed and can range from low-viscosity bone cement to high. There have been a number of lawsuits regarding high-viscosity bone cement loosening or failing to bond, which can cause both pain and loss of mobility in that joint.
What Is Bone Cement Made Of?
Bone cement is primarily made up of Poly(methyl methacrylate), also known as PMMA. It’s an acrylic glass that has been used in a variety of products, including some types of Plexiglas. It is considered to have good compatibility with human tissue, so it’s used in a wide variety of medical procedures such as joint replacements or cataract surgeries in eyes.
The actual ratios of ingredients in bone cement when mixed for surgery include:
- Poly(methyl methacrylate), or PMMA powder + MMA liquid – 90%
- Radiographic contrast material – 10%
- Antibiotics (added directly to the bone cement) – Varies
In joint replacement, bone cement is used to anchor artificial joints and is used most commonly in the following replacement surgeries:
Bone cement adheres the prosthetic joint and the bone together, while remaining flexible enough to allow for movement and to absorb forces acting on the body. It’s also used to remodel lost bone and to fill gaps in bones.
Low Viscosity vs. High Viscosity
Since bone cement is mixed together at the time of surgery, this mixture can range from “low-viscosity” to “high-viscosity” depending on the decisions of the surgical team. This just means that the thickness of the bone cement can vary.
Why Does Bone Cement Viscosity Matter?
Higher viscosity bone cement can be ready for use faster and can hold longer, so it has been used more often in surgeries.
Unfortunately, increasing evidence shows that high-viscosity bone cement can also produce a weaker bond. A weaker bond increases the risk of the bone cement loosening, which can cause chronic pain and immobility. This can require additional surgeries to fix, which results in more pain, medical bills, and down time for the patient.
Antibiotics in Bone Cement
Antibiotics are included in bone cement as a soluble powder that is released into the joint when the bone cement is applied. The intention is to prevent infection or to treat a pre-existing infection at the joint, but according to the British Journal of Anaesthesia, the use of antibiotics is controversial. This controversy is due to a risk of renal failure post-operation as well as other potential risks.
The frequency with which antibiotic-loaded bone cement is used varies depending on the country. For example, in Norway, only 48% of joint replacement surgeries used antibiotic-loaded bone cement, while in Sweden, the rate was 85%, and in Great Britain, the frequency was 69%.
The use of antibiotics in bone cement is more effective as a treatment for a pre-existing infection. In order to prevent postoperative infections, a lower dosage of antibiotics can be used (less than 1g of antibiotics per 40g of bone cement).
Types of Antibiotics
The types of antibiotics that are commonly used in bone cement include:
Disadvantages of Antibiotic-loaded Bone Cement
Too much antibiotics mixed into the bone cement can change the mechanical effects of the cement. Low-dosage antibiotic-loaded bone cement avoids this by including less than one gram of antibiotics, but any more than that can cause alterations to the structural properties of the bone cement.
Other disadvantages of antibiotic-loaded bone cement are:
- Antibiotic resistance
- Systemic toxicity
- Allergic reactions
- Cost implications
Who Makes Bone Cement?
A variety of medical device companies produce bone cement. The top five manufacturers of bone cement, according to a Technavio study, are:
- DJO Global
- Smith and Nephew
- Zimmer Biomet
Other major companies that produce bone cement include DuPuy Synthes, aap Implantate, Tecres, Medacta, and more.
FDA Recalls Certain Types of Bone Cement
Recalls of bone cement have been for reasons including a lack of antibiotics in the bone cement or because it had partially agglomerated, or partially clumped together. Other recalls occurred because of faulty or mislabeled packaging. These recalls have resulted in delays for patients requiring joint arthroplasty.
Why Would Someone Need a Joint Replacement?
Joint replacement surgery, also called replacement arthroplasty, is generally a last-resort procedure. It is only recommended when severe joint pain and injury isn’t alleviated by less-invasive methods. Joint replacement can be necessary after a physical injury to the joint, or because of a disease such as arthritis. It’s most commonly needed for hips and knees.
What Are the Risks?
Any surgical procedure does carry some risk. Joint replacement procedures are very common and increasingly use bone cement, especially of the high-viscosity kind, to adhere replacement joints to bone. With the exception of BCIS (Bone Cement Implantation Syndrome), complications that arise from joint replacement surgery are not generally fatal. The most common complication is loosening of the bone cement, which can cause chronic pain and loss of mobility.
Since most bone cement includes soluble antibiotics, the use of bone cement also carries the same risk as any other antibiotics. These risks include possible allergic reactions and a future resistance to antibiotics. There is also a risk that the antibiotics can alter the structure of the bone cement, making it less effective in the joint mechanically.
Complications of Bone Cement
Bone cement is both a powder and liquid methyl methacrylate (MMA), which can be an irritant and a carcinogen. It can be mixed at a variety of viscosities. With progressing research, high-viscosity bone cement seems likely to have a weaker bond.
Thermal Necrosis of Tissue
Thermal necrosis occurs when bone cement heats up while it is setting, which can cause the premature death of cells in the tissue around the bone cement. Bone cement must be carefully mixed with an initiator (dibenzoylperoxide) and a monomer (the liquid MMA) to reduce the heat in order to prevent thermal necrosis.
A failure to bond occurs when the bone cement simply fills the space between the prosthesis and the bone, but doesn’t properly adhere to them. This can cause immobility and chronic pain at that joint, which may require more surgeries to fix.
According to a study by the Journal of Arthroplasty, the number of knee replacement procedures using high-viscosity bone cement have increased in the past seven years. The most common cause of joint replacement failure is called aseptic loosening, which is the failure of the bond of the bone cement to the bone or the artificial joint. It is called aseptic because the failure was not caused by harmful microorganisms. Aseptic loosening has been found to occur more often with high-viscosity bone cement than with cements of lower viscosity.
Loosening can cause chronic pain, difficulty walking, and immobility. Loosening can be caused by a variety of factors, including the prosthetic joint, the patient’s body mass, and the density of the bone. However, aseptic loosening can also occur within the bone cement itself. Loosening requires revision, a surgery to replace the prosthetic joint, which can cause further loss of bone.
Bone Cement Implantation Syndrome (BCIS)
BCIS is somewhat rare, but potentially fatal. This syndrome occurs when the bone cement is first applied, generally during surgery, and has the following possible symptoms:
- Hypoxia (any part of the body not receiving enough oxygen)
- Hypotension (low blood pressure)
- Cardiac arrhythmia (irregular heartbeat)
- Cardiac arrest (the heart stops pumping blood)
BCIS is most commonly associated with hip replacement surgery. The highest risk factors of developing BCIS in surgery are:
- Pre-existing pulmonary hypertension
- Cardiac disease
- ASA III-IV (severe systemic disease)
- Long stem arthroplasty
- Intertrochanteric fracture
- Pathological fracture
The risk of the surgery depends on the health of the patient and the type of joint replacement. Patients with increased risk should be carefully monitored so symptoms of BCIS can be immediately addressed. The condition only occurs during the application of the bone cement and can be treated during the surgery as it becomes necessary.
Common Methods of Failure
The most common complication of bone cement is aseptic loosening, which is a type of loosening that doesn’t have to do with bacteria or other organisms. Aseptic loosening is the failure of the bone cement bond to either the bone or the replacement joint.
As a unique method of bone cement failure, BCIS occurs only during the initial application of cement during surgery. It isn’t necessary to monitor for symptoms of it after the fact.
If you or a loved one experienced BCIS during surgery or are experiencing symptoms of bone cement failure, seek medical attention. But don’t hesitate to give us a call and ask questions. You may have been the victim of faulty bone cement or negligence, and speaking with us doesn’t cost a thing unless you’re compensated first.
Warning Signs of Bone Cement Failure
Warning signs of aseptic loosening or other failure of bone cement include:
- Loss of mobility
- Chronic pain
- Decreased range of motion
- Swelling of the joint
- Persistent pain
One of the biggest signs that something is wrong will be pain that is new or different from what was experienced prior to the joint replacement surgery. If you experience any of these symptoms, contact a medical professional immediately. Infection of the surgical site causes pain as well can can be life-threatening.
What Happens If You Experience Complications?
If there was a failure in the bone cement or elsewhere in the replacement joint, additional surgery (revision) is often required to address the complications. This can place additional strain on the patient and their family, including more medical bills, more prescriptions, more time off work, and more pain.
Revisions and Healthy Bone
Revision is the replacement of a prosthetic joint.
Revisions can be much more complex than the initial operation and often result in further loss of healthy bone. Revision surgeries are also more expensive than the initial surgery. In the case of bone cement replacement, revisions would involve completely removing the faulty bone cement and replacing new, freshly-mixed cement.
This places the patient at risk of infection again, and the complex surgery may influence the risk of complications. The patient will also have to do physical therapy all over again to regain mobility and use of the new joint.
When Should You Consider a Bone Cement Lawsuit?
You can ask yourself the following questions to consider whether you have a case for a lawsuit:
- Was the complication avoidable and caused by the bone cement?
- What was the cause of the complication?
- Has your ability to work been affected?
- Did you have costly revision surgeries as a result of the complications?
Contact Farah and Farah for a free review of your case. You won’t be charged anything unless your case is successful.
Co-counsel will be associated on these cases.