OBJECTIVES

: The Centers for Medicare and Medicaid Services (CMS) initiated the Comprehensive Care for Joint Replacement Model (CJR) to improve outcomes through a bundled payment model. On October 1, 2017, CMS released new ICD-10 codes for Oxidized Zirconium bearing surfaces used in hip and knee replacement procedures. The objective of this study was to compare 180-day all-cause mortality rates in patients with and without Oxidized Zirconium hip and knee implants.

METHODS

: Medicare Fee-For-Service (FFS) Standard Analytic Files (SAF) were used to construct hip and knee (MS-DRG 469 or 470) 180-day all-cause mortality rates for episodes initiated in the fifteen-month period of Q4 2017 to Q1 2019. The study population included Medicare FFS patients continuously enrolled in Medicare Parts A and B for the 6-month period prior to the episode. The results were risk adjusted for multiple covariates and a greedy 5 to 1 propensity score match performed.

RESULTS

: For the hip implants, 7,629 episodes with Oxidized Zirconium implants and 38,145 episodes with non-Oxidized Zirconium implants were reviewed. Oxidized Zirconium patients had statistically significant 47.01% lower rates of 180-day all-cause mortality compared to those implanted with all other hip bearing surfaces.

For the knee implants, 16,046 episodes with Oxidized Zirconium implants and 80,230 episodes with non-Oxidized Zirconium implants were reviewed. Oxidized Zirconium patients had statistically significant 23.44% lower rates of 180-day all-cause mortality compared to those implanted with all other knee bearing surfaces.

When the hip and knee episodes were combined, Oxidized Zirconium patients had statistically significant 37.19% lower rates of 180-day all-cause mortality compared to those implanted with all other bearing surfaces.

CONCLUSIONS

: Oxidized Zirconium hip and knee bearing surfaces were associated with a lower rate of 180-day all-cause mortality in the episodes reviewed in this study.