title: Preoperative posterior tilt of at least 20° increased the risk of fixation failure in Garden-I and -II femoral neck fractures.
abstract: Background and purpose - It has been suggested that preoperative posterior tilt of the femoral head may increase the risk of fixation failure in Garden-I and -II femoral neck fractures. To investigate this association, we studied a cohort of 322 such patients. Patients and methods - Patients treated with internal fixation between 2005 and 2012 were retrospectively identified using hospital records and the digital image bank. 2 raters measured the preoperative posterior tilt angle and categorized it into 3 groups: < 10°, 10-20°, and ≥ 20°. The inter-rater reliability (IRR) was determined. Patients were observed until September 2013 (with a minimum follow-up of 18 months) or until failure of fixation necessitating salvage arthroplasty. The risk of fixation failure was assessed using competing-risk regression analysis, adjusting for time to surgery. Results - Patients with a posterior tilt of ≥ 20° had a higher risk of fixation failure: 19% (8/43) as compared to 11% (14/127) in the 10-20° category and 6% (9/152) in the < 10° category (p = 0.03). Posterior tilt of ≥ 20° increased the risk of fixation failure, with an adjusted hazard ratio of 3.4 (95% CI: 1.3-8.9; p = 0.01). The interclass correlation coefficient for angular measurements of posterior tilt was 0.90 (95% CI: 0.87-0.92), and the IRR for the categorization of posterior tilt into 3 groups was 0.76 (95% CI: 0.69-0.81). Interpretation - Preoperative posterior tilt of ≥ 20° in Garden-I and -II femoral neck fractures increased the risk of fixation failure necessitating salvage arthroplasty. The reliability of the methods that we used to measure posterior tilt ranged from good to excellent.
authors.affiliation: a Departments of Orthopedics Akershus University Hospital .|c Institute of Clinical Medicine, University of Oslo .
authors.forename: Filip C
authors.initials: FC
authors.lastname: Dolatowski
authors.affiliation: d Oslo Emergency Medical Agency .
authors.forename: Mina
authors.initials: M
authors.lastname: Adampour
authors.affiliation: b Oslo University Hospital .
authors.forename: Frede
authors.initials: F
authors.lastname: Frihagen
authors.affiliation: c Institute of Clinical Medicine, University of Oslo .|e Department of Pulmonary Medicine , Akershus University Hospital .
authors.forename: Knut
authors.initials: K
authors.lastname: Stavem
authors.affiliation: a Departments of Orthopedics Akershus University Hospital .|c Institute of Clinical Medicine, University of Oslo .
authors.forename: Stein
authors.initials: S
authors.lastname: Erik Utvåg
authors.affiliation: f Department of Orthopedic and Rheumatic Surgery , Kongsvinger Hospital , Norway.
authors.forename: Sigurd Erik
authors.initials: SE
authors.lastname: Hoelsbrekken
mesh_terms: D005265:Femoral Neck Fractures / Q000601:surgery*; D005593:Fracture Fixation, Internal; D000072506:Gardens; D006801:Humans; D015203:Reproducibility of Results; D012189:Retrospective Studies