title: Function and fixation of total hip arthroplasty in patients 25 years of age or younger.
abstract: BACKGROUND
  The treatment of end-stage hip disease in very young patients is controversial, with advocates for nonoperative treatment, hip arthrodesis and replacement procedures. The functional improvements in this group of patients are not well documented and whether the condition for which the surgery is performed influences function.
  
  
  OBJECTIVE
  We determined whether (1) modern THA provides major functional improvements; (2) disease-specific factors impact the magnitude of improvement; (3) these procedures are associated with early failures and complications; and (4) radiographically secure implant fixation is achieved with contemporary implants.
  
  
  METHODS
  We retrospectively reviewed 88 patients (102 hips) who had THA and were 25 years or younger at surgery. The most common diagnoses were osteonecrosis (44%) and secondary osteoarthritis (41%). All patients received a cementless socket of varying designs and all except five a cementless stem. Demographic data, Harris hip score, and Charnley classification were recorded. Radiographic evaluation was used to determine implant fixation. We identified complications and failure mechanisms. The minimum followup was 2 years (median, 4.2 years; range, 2-16 years).
  
  
  RESULTS
  The 95 nonrevised hips were followed clinically an average of 61 months. The mean Harris hip scores improved from 42 preoperatively to 83 postoperatively. Lower Harris hip scores were associated with systemic disease (Charnley Class C). Seven hips (7%) underwent revision. There were nine (9%) major complications. One hundred percent of femoral stems and 98% of acetabular components were well-fixed at last followup.
  
  
  CONCLUSIONS
  Contemporary total hip arthroplasty in patients 25 years of age and younger is associated with improved hip function, and secure fixation of cementless implants at early followup.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO 63110, USA. clohisyj@wudosis.wustl.edu
authors.forename: John C
authors.initials: JC
authors.lastname: Clohisy
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Oryhon
authors.forename: Thorsten M
authors.initials: TM
authors.lastname: Seyler
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Wells
authors.forename: Steve S
authors.initials: SS
authors.lastname: Liu
authors.forename: John J
authors.initials: JJ
authors.lastname: Callaghan
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mont
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D002648:Child; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D010020:Osteonecrosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult