title: Quantifying the demand for hip and knee replacement in Otago, New Zealand.
abstract: OBJECTIVE
  The purpose of this study is to quantify the current demand in Otago for hip and knee replacement.
  
  
  METHODS
  Hospital databases and the New Zealand Joint Registry were used to calculate the intervention rate for primary total hip (THR) or knee (TKR) replacement between February 2010 and February 2012. All patients meeting the clinical threshold but waiting for surgery were also recorded over the same period.
  
  
  RESULTS
  The intervention rate for THR and TKR in NZ in 2011 was 33.0/10000 while in Otago it has varied from 30.7 to 42.6 over the last 5 years. This is at or above the national average based on population share. Over a 2-year period the numbers reaching the clinical threshold and waiting for primary joint replacement surgery rose from 247 to 347 patients, while 1496 primary elective joints replacements were performed. The current demand for primary THR and TKR is 798 per year (41.7/10000 per year). The unmet demand is 73 cases per year.
  
  
  CONCLUSIONS
  The increased demand in Otago compared to the NZ average is due to greater numbers of people over the age of 55 years and the backlog of patients due to under provision relative to demand in previous years.
authors.affiliation: Department of Orthopaedic Surgery, Dunedin Public Hospital, Great King Street, Dunedin, New Zealand. david.gwynne-jones@otago.ac.nz
authors.forename: David
authors.initials: D
authors.lastname: Gwynne-Jones
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D016208:Databases, Factual; D005260:Female; D006301:Health Services Needs and Demand / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D015207:Osteoarthritis, Hip / Q000453:epidemiology / Q000601:surgery*; D020370:Osteoarthritis, Knee / Q000453:epidemiology / Q000601:surgery*; D012042:Registries; D014850:Waiting Lists