Bone cement used for surgical applications may help or hurt the patient, depending on the type of cement used, the patient’s reaction to the materials and the permanency of the cementation.

What Is Bone Cement Used For?

Bone cement is a thick, surgical grout-like material used to anchor prosthetic implants to existing bone in patients who undergo certain bone replacement surgeries.

What Materials Constitute Bone Cement?

Bone cement is made of polymethylmethacrylate (PMMA), which is known as plexiglass in general terms.

How Does Bone Cement Become Pliable, But is Later Able to Harden?

Bone cement is usually provided as two components, a powder and a liquid that must be mixed together right before the surgeon applies it.

The powder contains PMMA, and also may include benzoyl peroxide, which helps the mixture become doughy at room temperature. Zicronium dioxide, or barium sulphate, might be added to ensure the bone cement is visible later on an x-ray. Powdered antibiotics such as gentamicin or tobramycin could be included to help prevent infection.

Liquid components may include methylmethacrylate (MMA), which is a monomer that joins with PMMA. an accelerating component to ensure quick drying of the final cement product, and a stabilizer to prevent the components from damage from light or extreme temperatures prior to use, according to the International Journal of Orthopaedics Sciences.

How Many Types of Bone Cement Are There?

There are low viscosity, medium viscosity and high viscosity bone cements.

Low viscosity is runny, and setting times vary. Medium viscosity bone cement can range from low to high viscosity, depending upon how much time the mixed components sit before they are used. High viscosity cement is so thick that it’s usually a doughy consistency as soon as it’s mixed, and doctors must work quickly before high viscosity bone cement becomes too stiff to work with.

What Kind of Bone Cement is Used in Knee Replacement Surgeries?

In cemented knee replacement surgeries, many surgeons prefer to use high viscosity cement, but some scientists believe high viscosity cement is more apt to fail in knee replacements because the mixture doesn’t bond well to the bone.

What Is Aseptic Loosening?

Aseptic loosening of an implant means the prosthetic component has become loose, but not due to an infection. The National Center for Biotechnology Information found 13 cases in 2016 identifying high viscosity cement that resulted in the failure of the implant to stay bonded to the tibia. None of the implants that incorporated the use of low or medium viscosity cement showed any signs of losing their bond.

What Is Bone Cement Implantation Syndrome?

An implant patient with an adverse reaction to bone cement may develop a potentially life-threatening side effect known as bone cement implantation syndrome. Bone cement implantation syndrome symptoms may include:

• Hypoxia (lack of oxygen)
• Hypotension (low blood pressure)
• Increased pulmonary vascular resistance (reduced lung volume)
• Irregular heartbeats
• Cardiac arrest
• Blood clots
• Fat/marrow emboli (fat or marrow globules that enter the bloodstream)
• Unexplained loss of consciousness
• High blood pressure
• Pulmonary edema
• Other symptoms