Concern over bone cement syndrome unfounded if good THA technique is used

If joint replacement surgeons consistently use current bone cementing techniques, they can keep the risk of a possibly deadly condition to a minimum, according to a New York investigator.

In a presentation on bone cement implantation syndrome (BCIS) at the 24th Annual Current Concepts in Joint Replacement Winter Meeting, Kenneth A. Krackow, MD, said BCIS rates are currently one in 100 to 200 cases.

"It doesn't exist anymore, but a lot of people are worried about it," Krackow said, noting that concern about BCIS recently escalated at his institution following the recent deaths of two elderly patients following total joint arthroplasty.

To completely eliminate BCIS, orthopedic surgeons need to fully understand its causes and employ optimal cementation techniques, Krackow said. "Bone cement implantation syndrome is not due to the monomer. It is a microembolism phenomenon, and all of our brushing and lavage, etc., have virtually eliminated it."

Etiology, symptoms

BCIS is also not related to the amount of polymethylmethacrylate (PMMA) used and can even occur without cement, he said.

The syndrome, which is usually associated with total hip arthroplasty (THA), can include such symptoms as cardiac arrest, hypotension, anaphylactic response, increased microemboli presence, certain hypersensitivities and reflex bradycardia.

"We don't see it in total knees," Krackow said. Rather, its occurrence is likely related to differences in the procedures' surgical techniques.

The monomer is often suspected as a cause, but there is minimal support for that theory, he added. "It requires more than 30 times the normal concentration levels to get any kind of effect."

Retrograde filling

Researchers have seen the syndrome in the absence of cement after tightly filling the medullary canal with bone wax.

It causes high intramedullary pressure, which in turn causes medullary fat to gravitate toward the vasculature, creating embolic load, acute pulmonary hypertension, right ventricular dysfunction, ischemia, hypotension and sometimes death, Krackow said.

"It is not the methacrylate," he said. "In my personal experience in 30 years and in more than 3,000 cemented total hips, I have never seen this phenomenon."

Newer cementing techniques using lavage to clear bone spicules from the canal and low-viscosity cement introduced with a gun for retrograde filling have minimized the magnitude of the problem. In earlier techniques involving finger pressurization, excess debris was heavily pressurized, particularly at the sealed entry of the femur, using very low-viscosity fluid cement. That, in turn, moved particulate and fat toward the heart, Krackow said.

He urged colleagues performing THA to incorporate steps into their technique that fully eliminate bone debris, and only pressurize cement after the canal is filled.

For more information:
Kenneth A. Krackow, MD, can be reached at Buffalo General Hospital, Orthopedic Department, 100 High St., B-276, Buffalo, NY 14203; 716-859-1256; e-mail: kkrackow@buffalo.edu. He is a consultant to and receives royalties from Stryker.

Reference:
Krackow KA. Eliminating the bone cement syndrome: Achieving "a perfect 10." #43. Presented at the 24th Annual Current Concepts in Joint Replacement Winter Meeting. Dec. 12-15, 2007. Orlando, Fla.