title: The contribution of reverse shoulder arthroplasty to utilization of primary shoulder arthroplasty.
abstract: BACKGROUND
  We assessed the contribution of reverse shoulder arthroplasty to overall utilization of primary shoulder arthroplasty and present age- and sex-stratified national rates of shoulder arthroplasty. We also assessed contemporary complication rates, mortality rates, and indications for shoulder arthroplasty, as well as estimates and indications for revision arthroplasty.
  
  
  METHODS
  We used the Nationwide Inpatient Samples for 2009 through 2011 to calculate estimates of shoulder arthroplasty and assessed trends using Joinpoint (National Cancer Institute, Bethesda, MD) regression.
  
  
  RESULTS
  The cumulative estimated utilization of primary shoulder arthroplasty (anatomic total shoulder arthroplasty, hemiarthroplasty, and reverse shoulder arthroplasty) increased significantly from 52,397 procedures (95% confidence interval [CI], 47,093-57,701) in 2009 to 67,184 cases (95% CI, 60,638-73,731) in 2011. Reverse shoulder arthroplasty accounted for 42% of all primary shoulder arthroplasty procedures in 2011. The concomitant diagnosis of osteoarthritis and rotator cuff impairment was found in only 29.8% of reverse shoulder arthroplasty cases. The highest rate of reverse shoulder arthroplasty was in the 75- to 84-year-old female subgroup (77 per 100,000 persons; 95% CI, 67-87). Revision cases comprised 8.8% and 8.2% of all shoulder arthroplasties in 2009 and 2011, respectively, and 35% of revision cases were because of mechanical complications/loosening whereas 18% were because of dislocation.
  
  
  CONCLUSIONS
  The utilization of primary shoulder arthroplasty significantly increased in just a 3-year time span, with a major contribution from reverse shoulder arthroplasty in 2011. Indications appear to have expanded because a large percentage of patients did not have rotator cuff pathology. The burden from revision arthroplasties was also substantial, and efforts to optimize outcomes and longevity of primary shoulder arthroplasty are needed.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital and Harvard Medical School, Boston, MA, USA; Department of Orthopaedic Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. Electronic address: nitin.jain@vanderbilt.edu.
authors.forename: Nitin B
authors.initials: NB
authors.lastname: Jain
authors.affiliation: Department of Orthopaedic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000706:statistics & numerical data* / Q000639:trends; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000453:epidemiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012086:Reoperation / Q000706:statistics & numerical data; D012782:Shoulder / Q000601:surgery; D012785:Shoulder Joint / Q000601:surgery*; D014481:United States / Q000453:epidemiology
keywords: Reverse shoulder arthroplasty; utilization