title: Prevalence of heterotopic ossification in cemented versus noncemented total hip joint replacement in patients with osteoarthrosis: a randomized clinical trial.
abstract: OBJECTIVE
  To determine the prevalence of heterotopic bone formation in cemented versus noncemented total hip joint replacement.
  
  
  METHODS
  A prospective randomized controlled trial. Follow-up ranged from 2 to 6 years (mean 4 years).
  
  
  METHODS
  A university hospital.
  
  
  METHODS
  Two hundred and twenty-six patients who had primary or secondary osteoarthrosis of the hip were stratified according to type of fixation, surgeon and age. Patients were randomized within strata: 112 received noncemented total hip prostheses and 114 received cemented prostheses. The 2 groups were similar with respect to age and sex.
  
  
  METHODS
  Primary total hip arthroplasty. A cemented (methylmethacrylate) or noncemented prosthesis was inserted by a lateral surgical approach.
  
  
  METHODS
  The Brooker classification was used to grade heterotopic bone formation from postoperative radiographs.
  
  
  RESULTS
  Overall, 148 (66%) hips had no heterotopic ossification, 56 (25%) were Brooker class I, 14 (6%) were class II, 8 (3%) were class III and none were class IV. In the noncemented group of patients, 76 (68%) hips had no heterotopic ossification, 25 (22%) were Brooker class I, 7 (6%) were class II, 4 (4%) were class III and none were class IV. In the cemented group of patients, 72 (63%) hips had no heterotopic ossification, 31 (27%) hips were Brooker class I, 7 (6%) were class II, 4 (4%) were class III and none were class IV.
  
  
  CONCLUSIONS
  There was no significant difference in the prevalence of heterotopic ossification between cemented and noncemented total hip replacements in patients with osteoarthrosis.
authors.affiliation: London Health Sciences Centre, University Campus, Ont.
authors.forename: K N
authors.initials: KN
authors.lastname: Nayak
authors.forename: B
authors.initials: B
authors.lastname: Mulliken
authors.forename: C H
authors.initials: CH
authors.lastname: Rorabeck
authors.forename: R B
authors.initials: RB
authors.lastname: Bourne
authors.forename: M R
authors.initials: MR
authors.lastname: Woolfrey
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D004311:Double-Blind Method; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D020366:Methylmethacrylate; D008768:Methylmethacrylates / Q000009:adverse effects*; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology*; D015207:Osteoarthritis, Hip / Q000601:surgery; D015995:Prevalence; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors
chemical_list: D008768:Methylmethacrylates; D020366:Methylmethacrylate