Trends in Practice Patterns of Conventional and Computer-Assisted Knee Arthroplasty

An Analysis of 570,671 Knee Arthroplasties Between 2010 and 2017

Abdalrahman G. Ahmed; Raymond Kang, MA; Mohamed Hasan, MD, MPH; Yao Tian, PhD, MS, MPH; Hassan M. Ghomrawi, PhD, MPH


J Am Acad Orthop Surg. 2021;29(22):e1117-e1125. 

In This Article

Abstract and Introduction


Background: Despite advances in computer-assisted knee arthroplasty (CAKA), little is known about the uptake of this technology in recent years. We aimed to explore the utilization trends and practice variation of CAKA from 2010 to 2017 and investigate the predictors of CAKA adoption.

Methods: Patients undergoing conventional knee arthroplasty and CAKA were identified from the states of New York and Florida's administrative databases using the International Classification of Diseases version 9 and 10 procedure codes. Quarterly proportions of CAKA were calculated over the study period, and logistic regression was used to estimate predictors of CAKA utilization.

Results: Between 2010 and 2017, quarterly proportion of CAKAs increased from 4.89% in 2010Q1 to 9.45% in 2017Q3 in New York and from 4.03% in 2010Q1 to 5.73% in 2017Q3 in Florida. The general CA code was used to code most of the procedures (81%). Being Black (odds ratio [OR]: 0.63, 95% confidence interval [CI], 0.60 to 0.67), Hispanic (OR: 0.45, CI, 0.41 to 0.50), and having Medicaid coverage (OR: 0.46, CI, 0.40 to 0.53) were associated with lower likelihood of receiving CAKA in New York; similar findings were found in Florida.

Conclusion: Utilization of CAKA has increased substantially in both New York and Florida from 2010 to 2017; however, with most CAKAs reported using the general code, understanding adoption rates of various modalities was not possible. Black and Hispanic patients and those with Medicaid insurance are least likely to receive this high-precision technology, illustrating the presence of disparities in the adoption of CAKA.


Knee arthroplasty (KA) (including both total and partial) is one of the most commonly performed orthopaedic procedures in the United States and results in significant pain relief, improved function, and increased quality of life.[1–7] The number of KAs is projected to increase significantly over time due to the increasing prevalence of knee osteoarthritis and longevity of the cohort.[8,9] Aseptic loosening, dislocation, and periprosthetic fracture are among the most common reasons for KA failure and the need for revision.[10,11] Precise implant positioning to prevent axis malalignment improves prosthesis longevity, knee function, and quality of life.[1–7] Performance outcomes of KAs improved with increase in surgeon volume; however, a recent study showed that even among experienced high-volume surgeons, alignment outliers were prevalent (12%).[12–14]

A recent review of the literature showed that computer-assisted knee arthroplasty (CAKA) is associated with improved implant positioning compared with conventional KA.[15] Initially very expensive, CAKA technology has evolved significantly in the past few years, especially with the recent introduction of low-cost and the user-friendly handheld navigation systems. With such advancements, wide use of the technology is expected.[16,17] However, since its approval by the Food and Drug Administration in 2002, few population-level studies have examined CAKA utilization in the United States.[18] Those studies have shown an increasing trend in utilization, albeit CAKA still represented less than 4.51% of all KAs;[1,19–22] all previous studies have been restricted to data up to Q3 2015.

Therefore, the purpose of this study was to examine more recent CAKA utilization trends. We describe CAKA trends in 2 large states from 2010 to 2017 and examine predictors of CAKA uptake. We hypothesized that there was an increase in the adoption of different modalities of CAKA in more recent years and that CAKA was less prevalent among disadvantaged populations.