title: Differences in risk factor patterns between cervical and trochanteric hip fractures. Swedish Hip Fracture Study Group.
abstract: The two types of hip fracture--cervical and trochanteric femoral fractures--are generally considered together in etiologic studies. However, women with a trochanteric fracture may be more osteoporotic than those with cervical hip fractures, and have higher post-fracture mortality. To explore differences in risk factor patterns between the two types of hip fracture we used data from a large population-based case-control study in Swedish women, 50-81 years of age. Data were collected by questionnaire, to which more than 80% of subjects responded. Of the cases included, 811 had had a cervical fracture and 483 a trochanteric fracture during the study period; these cases were compared with 3312 randomly selected controls. Height and hormonal factors appeared to affect the risk of the two types of hip fracture differently. For every 5 cm of current height, women with a cervical fracture had an adjusted odds ratio (OR) of 1.23 (95% CI 1.15-1.32) compared with an OR of 1.06 (95% CI 0.97-1.15) for women with trochanteric fractures. Later menopausal age was protective for trochanteric fractures (OR 0.95, 95% CI 0. 91-0.99 per 2 years) but no such association was found for cervical fractures. Compared with never smokers, current smokers had an OR of 1.48 (95% CI 1.12-1.95) for trochanteric fractures and 1.22 (95% CI 0.98-1.52) for cervical fractures. Current hormone replacement therapy was similarly protective for both fracture types, but former use substantially reduced risk only for trochanteric fractures: OR 0. 55 (95% CI 0.33-0.92) compared with 1.00 (95% CI 0.71-1.39) for cervical fractures. These risk factor patterns suggest etiologic differences between the fracture types which have to be considered when planning preventive interventions.
authors.affiliation: Department of Surgery, University Hospital, Uppsala, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Michaëlsson
authors.forename: E
authors.initials: E
authors.lastname: Weiderpass
authors.forename: B Y
authors.initials: BY
authors.lastname: Farahmand
authors.forename: J A
authors.initials: JA
authors.lastname: Baron
authors.forename: P G
authors.initials: PG
authors.lastname: Persson
authors.forename: L
authors.initials: L
authors.lastname: Zidén
authors.forename: C
authors.initials: C
authors.lastname: Zetterberg
authors.forename: S
authors.initials: S
authors.lastname: Ljunghall
mesh_terms: D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D015444:Exercise; D005260:Female; D005265:Femoral Neck Fractures / Q000209:etiology / Q000517:prevention & control; D006620:Hip Fractures / Q000209:etiology* / Q000517:prevention & control; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D012307:Risk Factors; D012650:Self Disclosure; D012907:Smoking; D011795:Surveys and Questionnaires