title: Risk factors for cut-out of double lag screw fixation in proximal femoral fractures.
abstract: OBJECTIVE
  We assessed factors associated with cut-out after internal fixation of proximal femoral fractures using double lag screw nails.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  A university hospital.
  
  
  METHODS
  Patients with non-pathological intertrochanteric femur fractures and a minumum 90days follow-up who underwent internal fixation with dual lag screw nails were included. Potential risk factors for lag screw cut-out investigated by our study were: age, gender, body mass index, comorbidities (American Society of Anesthesiologists [ASA] classification), type of fracture (AO/OTA classification), fracture stability, side, operation time, implant length, reduction quality, tip-apex distance (TAD), and lag screw configuration. Logistic regression was used to investigate potential predictors of screw cut-out.
  
  
  RESULTS
  Eighty-five of the 118 patients with hip fractures treated between February 2010 and November 2013 at our institution met the inclusion criteria for the study. Fifty-eight patients were female (68.2%), mean age was 77.4 (range: 50-95 years), mean follow up was 380days (range: 150days-2.5 years), and cut of was observed in 9 patients (10.5%). The following variables identified through univariate analysis with p<0.2 were included in multivariant logistic regression model: age, side, reduction quality, implant length, TAD and ASA score. Only TAD (p=0.003) was found to be significant in the multivariant model.
  
  
  CONCLUSIONS
  Our study confirmed that risk factors for cut-out with single-lag screw devices are also applicable to dual-lag screw implants. We found that TAD was a significant factor for cut-out in dual-lag screw implants. Thus, screw cut-out can be minimized by optimizing screw position.
authors.affiliation: Hacettepe University Faculty of Medicine Department of Orthopaedics and Traumatology, Ankara, Turkey; Mardin Kiziltepe State Hospital, Mardin, Turkey. Electronic address: kadirbuyukdogan@gmail.com.
authors.forename: Kadir
authors.initials: K
authors.lastname: Buyukdogan
authors.affiliation: Hacettepe University Faculty of Medicine Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Omur
authors.initials: O
authors.lastname: Caglar
authors.affiliation: Hacettepe University Faculty of Medicine Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Samet
authors.initials: S
authors.lastname: Isik
authors.affiliation: Hacettepe University Faculty of Medicine Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Mazhar
authors.initials: M
authors.lastname: Tokgozoglu
authors.affiliation: Hacettepe University Faculty of Medicine Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Bulent
authors.initials: B
authors.lastname: Atilla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001858:Bone Nails; D001863:Bone Screws; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D005594:Fracture Fixation, Intramedullary / Q000009:adverse effects / Q000295:instrumentation*; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D011859:Radiography; D012016:Reference Values; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014421:Turkey
keywords: Cut-out; Intertrochanteric fractures; Logistic regression; Prognostic level II; Risk factors; Tip-apex distance