Published 12/20/2023
Rebecca Araujo

Study of AJRR Data Investigates Trends in TKA Technology Use at Safety-net Hospitals

An analysis of data from the AAOS American Joint Replacement Registry (AJRR) identified disparities in the use of premium total knee arthroplasty (TKA) technologies among safety-net hospitals. This study was presented as a poster during the AAOS 2023 Annual Meeting by Stefan D. Sarkovich, BS, of LSU Health Sciences Center.

Safety-net hospitals are defined as those that offer care to patients regardless of insurance status or ability to pay; these institutions often serve a higher number patients who are low-income, have no insurance or Medicaid/Medicare, or are otherwise vulnerable compared with “non–safety-net” hospitals. Although these hospitals may still offer major procedures such as TKA, they may lack the means to adopt premium technologies.

A previous study from this research team assessed the rate of premium technology use (i.e., ceramic femoral heads, dual mobility, or robotic assistance [RA]) in total hip arthroplasty performed in safety-net hospitals; that study was published in the Nov. 1, 2022, issue of the Journal of the AAOS®. The researchers found that dual mobility and RA were less frequently utilized in safety-net hospitals. However, ceramic femoral head utilization was not different between hospital designations.

For this poster study, the researchers assessed trends in the use of two premium TKA technologies: uncemented implant fixation and surgery utilizing RA. AJRR was utilized to identify a nationwide cohort of adult TKA patients who were treated with either of these technologies. Safety-net hospital status was assessed, as well as patient demographics and other hospital factors, including geographic region, hospital size, and teaching affiliation. A multivariate regression analysis was conducted to identify any significant associations.

From TKA cases identified within AJRR, 936,343 TKAs utilized uncemented implants, and 285,920 utilized RA. The investigators compared the number of cases from safety-net hospitals to the number from non–safety-nets. The use of RA was evaluated between 2015 and 2020, and uncemented implant use was assessed from 2011 through 2020.

The researchers found lower utilization rates for both technologies associated with safety-net hospitals. For RA, though usage was low for both hospital designations in 2015, by 2020, the rates of usage were around 15 percent for non–safety-net and 10 percent for safety-net hospitals. For uncemented TKA, the incidence of usage increased significantly from 2017 onward for both designations. In 2020, utilization rates were around 12 percent and 9 percent for non–safety-net and safety-net hospitals, respectively.

The authors noted, “Older patients were more likely to receive RA TKA, while conversely, they were less likely to receive uncemented TKA.” In addition, teaching hospitals were significantly more likely to use RA during TKA; however, this relationship was not found for uncemented implants.

In their conclusion, the study authors emphasized, “Trends in utilization of premium TKA technologies are not equal in hospitals with marginalized patient populations such as safety-net hospitals.” They also noted that the increasing use of uncemented implants may suggest “a shift for uncemented TKA to becoming a standard of care in the future.”

Mr. Sarkovich’s coauthors of “Analyzing Utilization Rates of Premium Technologies in Total Knee Arthroplasty between Safety-net Hospitals and Non–safety-net Hospitals” are Peter C. Krause, MD, FAAOS; Andrew G. Chapple, PhD; and Vinod Dasa, MD, FAAOS.

Visit aaos.org/ameducation to view an ePoster of this study or any AAOS 2023 Annual Meeting poster.

Rebecca Araujo is the managing editor of AAOS Now. She can be reached at raraujo@aaos.org.


  1. Sarkovich S, Chapple A, Dasa V, Krause P: Comparison of premium technology utilization in total hip arthroplasty between safety-net hospitals and non–safety-net hospitals. J Am Acad Orthop Surg 2022;30(21):e1402-e1410.