A randomized study from Warwick, Great Britain (Sprowson AP, Bone Joint J, 2016), showed that the use of dual antibiotics in routine use significantly reduces the rate of SSI [surgical site infection] compared with standard.
Spanish investigators found (Sanz-Ruiz P, J Arthroplasty 2017), before they put antibiotics in the bone cement they had an infection rate of 4.3% for the hips and after 1.8%. This is a significant difference.
Is it evidenced based? No, it isn’t. There is still no evidence-based study. I’m coming closer to you, Tom. But despite that, in Australia and most other countries, surgeons use antibiotics in 100% of the bone cement.
The International Consensus is that antibiotic impregnated bone cement reduces the incidence of infection—but it should be selected only for patients at higher risk.
Dr. Sculco: When it comes to the use of antibiotic composites in primary joint replacement, well I think we may have a little difference of opinion.
There is no question that periprosthetic joint infection is a huge, catastrophic complication. But infection rates have definitely declined. Use of parenteral perioperative antibiotics, better surgical techniques, speed of surgery … lots of things we’ve done to reduce the incidence of infection. In the literature today, the incidence is anywhere between, in the best of centers, 0.1% to around 1%.
The other problem I see in North America is 90 – 95% of our hips are non-cemented.
No question. There is a place for it—high risk patients, as Thorsten just said—I agree with him 100%. I think you should use it in the primary knee; history of previous infection; diabetic; immunosuppressed; inflammatory arthritis. All a good place to use it. And in revision surgery—100% agree with him.
But there are some disadvantages to using it routinely. Cost is one. The emergence of resistant organisms is another. Alteration of mechanical properties is a third. If you get carried away and you use more, certainly you can impede the mechanical properties.
If you look at cost, our implant and antibiotic costs are ridiculously high. Antibiotic cement can add anywhere between $450 and $900 to a case. Under bundled payment programs, the increased cost of the antibiotic-loaded cement is not going to be reimbursed. So, it’s going to be less revenue to the institution ultimately for that event.
I did a little math here and if we do 500 knee replacements, because that’s the population I think it would apply to in the United States, and let’s say there was a 50% utilization by our surgeons, the additional cost to the system … if you look at $500 as the added cost … would be around $125 million. Now if you calculate a high infection rate for total knee replacement of 1%, for it to be cost effective, you would have to reduce the infection rate to 0.04% to be cost neutral, which would be literally impossible.
