title: Bone mineral density is not related to heterotopic ossification after total hip arthroplasty.
abstract: OBJECTIVE
  Heterotopic ossification (HO) after total hip arthroplasty (THA) is a frequent complication that compromises the success of this procedure; however, its precise pathogenesis is unknown. Patient-related risk factors have previously been investigated to predict patients likely to have HO. In this study, we compared bone mineral density (BMD) between patients with and without HO after THA.
  
  
  METHODS
  We measured BMD of the lumbar spine, radius, and calcaneus using dual-energy X-ray absorptiometry in 98 females who were scheduled to undergo THA. Radiographs were graded for the presence of HO according to the criteria of Brooker at a minimum follow-up of two years following THA. BMD were compared between those with HO and those without.
  
  
  RESULTS
  In total, HO was observed in 20 of 98 hips. There were no significant differences in age, height, weight, body mass index, and pre-operative total hip score between the HO and non-HO groups. No significant difference was observed in BMD of the lumbar spine, distal radius, mid-radius, and calcaneus between the two groups.
  
  
  CONCLUSIONS
  Our findings suggest that generalized BMD is not related to the occurrence of HO after THA in women.
authors.affiliation: Department of Orthopedic Surgery, Nagasaki Medical Center, 2-1001-1 Kubara, Omura, 852-8562, Japan. kokano@nmc.hosp.go.jp
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Okano
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Aoyagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.forename: Satoru
authors.initials: S
authors.lastname: Motokawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsumoto
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism*; D015897:Comorbidity; D005260:Female; D006621:Hip Joint / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology*; D015207:Osteoarthritis, Hip / Q000601:surgery; D011183:Postoperative Complications / Q000453:epidemiology