Study Questions Whether “Nickle-Free” Total Knee Arthroplasty Is Truly Nickle-Free
For Immediate Release
November 14, 2021
Dallas – A study presented at the 2021 AAHKS Annual Meeting called into question the rationale of utilizing more expensive, lower-nickel components for total knee arthroplasty (TKA) based on a patient’s nickel or chromium allergy. Standard TKA components contain cobalt-chromium (Co-Cr), which may cause allergic reactions. Nickel-free, hypoallergenic components are an option for patients who have a known or suspected allergy.
Lead author Charles M. Lawrie, MD, MSc, and co-authors Ryan M. Nunley, MD, Tyler Moon, MD, Toby N. Barrack, BA, Kimberly A. Bartosiak, MD, Rick W. Wright, MD, Robert L. Barrack, MD, sought to determine how much metal is present in the knee joint after performing a knee replacement with standard components vs. “nickel-free” components.
Researchers identified 24 patients receiving standard Co-Cr components and 17 receiving Oxinium nickel-free components. They collected joint fluid immediately prior to surgery as well as from drainage fluid the following morning and examined the fluid to determine the amount and type of metal debris generated from both types of TKA.
Patients in the standard group had statistically higher levels of nickel, cobalt and chromium. Patients in the nickel-free group had 9.5 times higher chromium and 5.1 times higher nickel after surgery than before, while cobalt levels were not significantly different. The nickel levels generated in performing an Oxinium TKA was 3.3 times higher than a Co-Cr TKA.
In conclusion, researchers found a substantial degree of nickel generation resulting from performing a hypoallergenic “nickel-free” TKA. This calls into question the rationale of using more expensive, lower-nickel components based on a patient’s known or suspected nickel or chromium allergy.
This study received the AAHKS James A. Rand, MD, Young Investigator’s Award during the 2021 Annual Meeting. This award recognizes young investigators who demonstrate clinical excellence in knee-related research.
About the American Association of Hip and Knee Surgeons
Established in 1991, the mission of AAHKS is to advance hip and knee patient care through education and advocacy. AAHKS has a membership of over 4,000 surgeons and other hip and knee health care professionals.