title: The Epidemiology of Upper Extremity Fractures in the United States, 2009.
abstract: BACKGROUND
  No single epidemiological study of upper extremity fractures exists in the United States using data from all payers. Current epidemiological estimates are based on case series, foreign databases, or Medicare data, which are not representative of the entire US population. The objective of this project was to accurately describe the incidence of fractures of the upper extremity in a representative sample of the US population.
  
  
  METHODS
  Using International Classification of Disease, Ninth Edition codes for patient visits reported in the 2009 State Emergency Department Database and the State Inpatient Database, available from the Healthcare Cost and Utilization Project, and 2010 US Census data, we calculated the annual incidence rates per 10,000 persons of upper extremity fractures of all patients, regardless of age or payer type. This was done using a representative national sample from 8 states: Arizona, California, Iowa, Maryland, Massachusetts, New Jersey, and Vermont.
  
  
  RESULTS
  Overall, in this population of over 87 million Americans, there were 590,193 fractures of the upper extremity, yielding an annual incidence of 67.6 fractures per 10,000 persons. Distal radius and ulna fractures were the most common upper extremity fractures (16.2 fractures per 10,000 persons), followed by hand fractures (phalangeal and metacarpal fractures; 12.5 and 8.4 per 10,000, respectively), proximal humerus fractures (6.0 per 10,000), and clavicle fractures (5.8 per 10,000). The most common type of fracture for all age groups was distal radius fractures, except in the 18- to 34-year-old group, in which metacarpal and phalangeal fractures were more common (16.1 and 12.5 per 10,000, respectively) and the 35- to 49-year-old group, in which phalangeal fractures were most common (11.5 per 10,000). The incidence of distal radius fractures was bimodal, with the highest rates in the under 18 and over 65 age groups (30.18 and 25.42 per 10,000, respectively) with lower rates in the middle age groups. The most common type of fracture for males was phalangeal fractures (11.5 per 10,000), and distal radius and ulna fractures were the most common type for females (11.8 per 10,000). Interestingly, phalangeal and metacarpal fractures varied by socioeconomic status (SES), which decreased with increasing SES. No other fracture type varied by SES.
  
  
  CONCLUSIONS
  Epidemiological studies are necessary for research, clinical applications, and public health and health policy initiatives. This study reports national estimates of upper extremity fractures with subgroup analysis.
authors.affiliation: *Department of Orthopaedic Surgery, Columbia University Medical Center, New York, NY; and †Rosenberg Cooley Metcalf Clinic, Park City, UT.
authors.forename: John W
authors.initials: JW
authors.lastname: Karl
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Olson
authors.forename: Melvin P
authors.initials: MP
authors.lastname: Rosenwasser
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001134:Arm Injuries / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D050723:Fractures, Bone / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D014481:United States; D055815:Young Adult