title: Trends in the use of total ankle replacement and ankle arthrodesis in the United States Medicare population.
abstract: BACKGROUND
  Total ankle replacement (TAR) has gained acceptance as an alternative to traditional ankle arthrodesis (AA) for end-stage ankle arthritis. Little is known about long-term trends in volume, utilization, and patient characteristics. The objective of this study was to use longitudinal data to examine temporal trends in TAR and AA.
  
  
  METHODS
  We identified all United States fee-for-service Medicare beneficiaries who underwent TAR and AA between 1991 and 2010 (n = 5871 and 29 532, respectively). We examined changes in patient demographics and comorbidity, nationwide and hospital volume, per capita utilization, and length of stay (LOS).
  
  
  RESULTS
  Between 1991 and 2010, both TAR and AA patients had modest shifts in characteristics, with higher rates of diabetes and obesity. Overall, TAR Medicare volume increased by more than 1000% from 72 procedures in 1991 to 888 in 2010, while per-capita standardized utilization increased 670.8% (P < .001). AA volume increased 35.8% from 1167 procedures in 1991 to 1585 in 2010, while per-capita standardized utilization declined 15.6% (P < .001). The percentage of all US hospitals performing TAR increased nearly 4-fold from 3.1% in 1991 to 12.6% in 2010, while the proportion performing AA remained relatively unchanged. LOS decreased dramatically from 8.7 days in 1991 to 2.3 days in 2010 in TAR and from 5.5 days to 3.2 days in AA (P < .001).
  
  
  CONCLUSIONS
  Between 1991 and 2010, Medicare beneficiaries undergoing either TAR or AA became more medically complex. Both volume and per-capita utilization of TAR increased dramatically but remained nearly constant for AA. At the same time, mean hospital volume for both procedures remained low. Further research should be directed toward determining design, surgeon, and hospital variables that relate to optimal outcomes following TAR, which has become increasingly used for the treatment of ankle arthritis.
  
  
  METHODS
  Level III, comparative series.
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Iowa Carver College of Medicine, Iowa City, IA, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pugely
authors.forename: Xin
authors.initials: X
authors.lastname: Lu
authors.forename: Annunziato
authors.initials: A
authors.lastname: Amendola
authors.forename: John J
authors.initials: JJ
authors.lastname: Callaghan
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Martin
authors.forename: Peter
authors.initials: P
authors.lastname: Cram
mesh_terms: D000368:Aged; D000843:Ankle Joint / Q000601:surgery*; D001168:Arthritis / Q000453:epidemiology / Q000601:surgery*; D001174:Arthrodesis / Q000706:statistics & numerical data* / Q000639:trends; D019643:Arthroplasty, Replacement / Q000706:statistics & numerical data* / Q000639:trends; D015897:Comorbidity; D006801:Humans; D007902:Length of Stay; D006278:Medicare; D014481:United States
keywords: CMS; Medicare; ankle arthrodesis; ankle fusion; outcomes; total ankle; utilization