OBJECTIVES:

The United States 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. The objective of this study was to compare clinical outcomes and costs of Oxidized Zirconium versus non-Oxidized Zirconium hip implants when a hip fracture is present at admission within 90-day episodes of care.

METHODS:

Medicare Fee-For-Service (FFS) Standard Analytic Files (SAF) were used to construct hip (MS-DRG 469 or 470) 90-day episodes of care initiating in the nine-month time period beginning Q4 2017 and ending Q2 2018. The study population included Medicare FFS patients continuously enrolled in Medicare Parts A and B for the 6-month period prior to the episode and a hip fracture present at admission. The results were risk adjusted and a greedy 5 to 1 propensity score match was performed.

RESULTS:

188 patients treated with Oxidized Zirconium and 939 patients treated with non-Oxidized Zirconium were identified and analyzed for 90-day episodes. Oxidized Zirconium patients had statistically significant 22.1% lower rate of discharge to skilled nursing facilities (SNFs), 58.4% lower rates of 30-day all-cause readmissions, 51.9% lower rates of 90-day all-cause readmissions and 86.4% lower rate of 180-day all-cause mortality compared to those implanted with all other hip bearing surfaces. Oxidized Zirconium episodes also showed $4,409 (25%) lower average post-acute costs per episode.

CONCLUSIONS:

Oxidized Zirconium hip bearing surfaces were associated with lower costs, fewer readmissions and significantly lower mortality across 90-day episodes evaluated when a hip fracture is present at admission.