title: Why do Hong Kong patients need total hip arthroplasty? An analysis of 512 hips from 1998 to 2010.
abstract: BACKGROUND
  The number of patients undergoing total hip replacement surgeries has increased as a result of a rise in the ageing population. This study reviewed the demographics and disease spectrum leading to primary total hip replacement in the Chinese population from 1998 to 2010.
  
  
  METHODS
  This case series was conducted in a university teaching hospital in Hong Kong. Data from the prospective joint registry of all patients who underwent primary total hip replacement from January 1998 to December 2010 were reviewed. Patients' age and sex, diagnosis, as well as the Harris Hip Scores before operation and at the last follow-up were described.
  
  
  RESULTS
  There were 512 primary total hip replacements performed on 419 patients (43.4% males) during the study period. All had clinical follow-up for at least 2 years. The mean age of the patients was 57.6 (standard deviation, 16.6) years. In males, the main aetiology was osteonecrosis (50.9%), ankylosing spondylitis (19.5%), and post-traumatic arthritis (8.5%). For females, it was osteonecrosis (33.0%), primary osteoarthritis (18.8%), and post-traumatic arthritis (15.8%). Alcohol-induced (52.5%) and idiopathic (40.7%) was the most common cause of osteonecrosis in males and females, respectively. The mean preoperative Harris Hip Score and that at last follow-up was 43.9 (standard deviation, 18.3) and 89.7 (standard deviation, 13.0), respectively.
  
  
  CONCLUSIONS
  Osteonecrosis was the most common aetiology leading to total hip replacement although there were different causes in both sexes leading to it. The clinical result in terms of Harris Hip Score was good for all patients who required total hip replacement.
authors.affiliation: Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: V Wk
authors.initials: VW
authors.lastname: Chan
authors.affiliation: Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: P K
authors.initials: PK
authors.lastname: Chan
authors.affiliation: Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: K Y
authors.initials: KY
authors.lastname: Chiu
authors.affiliation: Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: C H
authors.initials: CH
authors.lastname: Yan
authors.affiliation: Department of Orthopaedics and Traumatology, Queen Mary Hospital, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: F Y
authors.initials: FY
authors.lastname: Ng
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000601:surgery; D019644:Arthroplasty, Replacement, Hip / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000150:complications*; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012737:Sex Factors
keywords: Arthroplasty, replacement, hip; Osteonecrosis; Treatment outcome