title: Bone mineral density is not related to osteophyte formation in osteoarthritis of the hip.
abstract: OBJECTIVE
  Reports have suggested that bone mineral density (BMD) is higher in patients with osteoarthritis (OA) of the hip than in healthy controls. Various types of OA of the hip caused by osteophyte formation were observed on radiographs during progression to the advanced degenerative stage, and the preoperative type of OA was reported to influence the results of surgical treatment. However, the mechanism underlying the development of different types of OA is still unknown. We measured BMD of patients with hip OA and determined whether higher BMD was observed in patients with osteophyte formation than in those without osteophytes.
  
  
  METHODS
  We measured BMD of the lumbar spine, radius, and calcaneus using dual-energy x-ray absorptiometry in 88 women who were scheduled to undergo total hip arthroplasty for endstage OA. Hips were evaluated for osteophyte formation using Bombelli's classification; 31 were graded as atrophic type, 30 as normotrophic, and 27 as hypertrophic. BMD at different skeletal sites were compared among the 3 types of OA.
  
  
  RESULTS
  No significant difference in BMD of the lumbar spine, ultradistal radius, mid-radius, or calcaneus was observed among the atrophic, normotrophic, and hypertrophic types of OA.
  
  
  CONCLUSIONS
  Our data suggest that osteophyte formation is not related to general BMD. Factors other than general bone status, for example the morphology of the hip joint, need to be analyzed to determine the pathomechanism of osteophyte formation in the osteoarthritic hip.
authors.affiliation: Department of Orthopedic Surgery, Nagasaki Medical Center, 2-1001-1 Kubara, Omura 856-8562, 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: Ko
authors.initials: K
authors.lastname: Chiba
authors.forename: Satoru
authors.initials: S
authors.lastname: Motokawa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsumoto
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000503:physiopathology; D054850:Osteophyte / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012720:Severity of Illness Index