title: Yearly Trends in Elective Shoulder Arthroplasty, 2005-2013.
abstract: To evaluate the change in incidence rate of shoulder arthroplasty, the utilization of shoulder arthroplasty for specific indications, and the surgeon volume trends associated with these procedures between 2005 and 2013.
  
  
  
  A population-based cohort study was conducted using the more than 7 million members of an integrated health care system in California. Cases of shoulder arthroplasties performed between 2005 and 2013 were identified using a shoulder arthroplasty registry. Annual shoulder arthroplasty incidence rates per 100,000 patients were determined, and adjusted yearly changes in rates were estimated using incidence rate ratios (IRRs). Changes in surgeon volumes by year and number of surgeons performing different procedures were also compared.
  
  
  
  The incidence of shoulder arthroplasty per 100,000 members increased from 6.1 (95% confidence interval [95% CI] 5.5-6.7) in 2005 to 13.4 (95% CI 12.5-14.2) in 2013. In patients with osteoarthritis, there was increasing utilization of total shoulder arthroplasty (IRR 1.12 [95% CI 1.11-1.14]) and decreasing utilization of hemiarthroplasty (IRR 0.91 [95% CI 0.89-0.94]). For patients with rotator cuff tear arthropathy, there was an increase in utilization of reverse total shoulder arthroplasty (IRR 1.33 [95% CI 1.29-1.37]) but no change in hemiarthroplasty (IRR 0.99 [95% CI 0.92-1.05]). The average surgeon yearly volume increased for total shoulder arthroplasty (P < 0.001) and for reverse total shoulder arthroplasty (P = 0.020).
  
  
  
  Shoulder arthroplasty is being used with greater frequency in this population. Surgeons are performing a greater yearly volume of total shoulder arthroplasty and reverse total shoulder arthroplasty.
authors.affiliation: The Permanente Medical Group, Sacramento, California.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Dillon
authors.affiliation: Kaiser Permanente, San Diego, California.
authors.forename: Priscilla H
authors.initials: PH
authors.lastname: Chan
authors.affiliation: Medicine and Devices Surveillance Centre of Research Excellence, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Maria C S
authors.initials: MCS
authors.lastname: Inacio
authors.affiliation: Southern California Permanente Medical Group, San Diego.
authors.forename: Anshuman
authors.initials: A
authors.lastname: Singh
authors.affiliation: Southern California Permanente Medical Group, Anaheim.
authors.forename: Edward H
authors.initials: EH
authors.lastname: Yian
authors.affiliation: Southern California Permanente Medical Group, Harbor City.
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Navarro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000072228:Arthroplasty, Replacement, Shoulder / Q000706:statistics & numerical data / Q000639:trends*; D002140:California; D002648:Child; D002675:Child, Preschool; D017558:Elective Surgical Procedures; D005260:Female; D062785:Hemiarthroplasty / Q000706:statistics & numerical data / Q000639:trends*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D000072161:Orthopedic Surgeons / Q000639:trends*; D010818:Practice Patterns, Physicians' / Q000639:trends*; D012042:Registries; D012785:Shoulder Joint / Q000601:surgery*; D013997:Time Factors; D016526:Workload; D055815:Young Adult