title: Correlation between mechanical stress by finite element analysis and 18F-fluoride PET uptake in hip osteoarthritis patients.
abstract: 18F-fluoride positron emission tomography (18F-fluoride PET) is a functional imaging modality used primarily to detect increased bone metabolism. Increased 18F-fluoride PET uptake suggests an association between increased bone metabolism and load stress at the subchondral level. This study therefore examined the relationship between equivalent stress distribution calculated by finite element analysis and 18F-fluoride PET uptake in patients with hip osteoarthritis. The study examined 34 hips of 17 patients who presented to our clinic with hip pain, and were diagnosed with osteoarthritis or pre-osteoarthritis. The hips with trauma, infection, or bone metastasis of cancer were excluded. Three-dimensional models of each hip were created from computed tomography data to calculate the maximum equivalent stress by finite element analysis, which was compared with the maximum standardized uptake value (SUVmax) examined by 18F-fluoride PET. The SUVmax and equivalent stress were correlated (Spearman's rank correlation coefficient ρ=0.752), and higher equivalent stress values were noted in higher SUVmax patients. The correlation between SUVmax and maximum equivalent stress in osteoarthritic hips suggests the possibility that 18F-fluoride PET detect increased bone metabolism at sites of stress concentration. This study demonstrates the correlation between mechanical stress and bone remodeling acceleration in hip osteoarthritis.
authors.affiliation: Department of Orthopaedic Surgery, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-004, Japan.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Hirata
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Inaba
authors.forename: Naomi
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ike
authors.forename: Yohei
authors.initials: Y
authors.lastname: Yukizawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujimaki
authors.forename: Taro
authors.initials: T
authors.lastname: Tezuka
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
authors.forename: Tomio
authors.initials: T
authors.lastname: Inoue
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Saito
mesh_terms: D000328:Adult; D016723:Bone Remodeling; D005260:Female; D020342:Finite Element Analysis; D005459:Fluorides / Q000378:metabolism*; D005462:Fluorine Radioisotopes / Q000378:metabolism; D006621:Hip Joint / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000145:classification / Q000000981:diagnostic imaging / Q000378:metabolism*; D010012:Osteogenesis; D010147:Pain Measurement; D049268:Positron-Emission Tomography; D012720:Severity of Illness Index; D013314:Stress, Mechanical
chemical_list: D005462:Fluorine Radioisotopes; D005459:Fluorides
keywords: 18F-fluoride PET; bone formation; finite element analysis; hip osteoarthritis; mechanical stress