title: Discrepancy in bone mineral densities at different skeletal sites in hip osteoarthritis patients.
abstract: OBJECTIVE
  Increased femoral neck bone mineral density (BMD) in a hip with osteoarthritis (OA) has been previously reported, however, it is possible that increased BMD at sites other than the hip joint is influenced by the disease process of OA. Therefore, we measured BMD at locations different from the hip joint and determined whether higher BMD was also observed at these different skeletal sites in hip OA patients.
  
  
  METHODS
  We measured BMD in 68 women (average age 61.0 years) scheduled to undergo total hip arthroplasty for end-stage OA and 100 healthy women (average age 60.9 years) as age-matched controls. BMD at the lumbar spine, radius, and calcaneus was measured by dual-energy X-ray absorptiometry (DXA). Moreover, we measured speed of sound (SOS), broadband ultrasound attenuation (BUA), and stiffness index of the calcaneus by quantitative ultrasonography (QUS).
  
  
  RESULTS
  BMD obtained by DXA at the lumbar spine and radius was significantly higher in hip OA patients than in controls. However, at the calcaneus, no significant differences were observed between the groups in BMD obtained by DXA. SOS, BUA, and stiffness index obtained by QUS were significantly lower in the OA group than in controls.
  
  
  CONCLUSIONS
  Higher BMDs of the spine and radius suggest that the incidence of osteoporosis is inversely associated with the incidence of OA. However, it remains unclear whether lack of difference in BMD and lower SOS, BUA, and stiffness index of the calcaneus in the OA group was secondary to the effect walking disturbance resulting from hip pain. Our data suggest that hip OA patients have higher BMD than healthy women, and that inactivity or immobilization caused by hip OA may reduce BMD in the lower limb.
authors.affiliation: Department of Orthopedic Surgery, Nagasaki Prefectural Center of Medicine and Welfare for Children , Isahaya , Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Okano
authors.forename: Masako
authors.initials: M
authors.lastname: Ito
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Aoyagi
authors.forename: Makoto
authors.initials: M
authors.lastname: Osaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Enomoto
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D015519:Bone Density / Q000502:physiology*; D002111:Calcaneus / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging*; D011859:Radiography; D011884:Radius / Q000000981:diagnostic imaging*