title: Risk factors of avascular necrosis of the femoral head and fixation failure in patients with valgus angulated femoral neck fractures over the age of 50 years.
abstract: BACKGROUND
  The aim of our study was to identify the risk factors for avascular necrosis of the femoral head (AVN) and fixation failure (FF) after screw osteosynthesis in patients with valgus angulated femoral neck fractures.
  
  
  METHODS
  We conducted a retrospective study of 308 patients (mean age, 72.5 years, range, 50-97 years), with a mean follow-up of 21.4 months (range, 12-64 months). The risk for failure in treatment (FIT) associated with patient- and fracture-related factors was evaluated by logistic regression analyses.
  
  
  RESULTS
  FIT was identified in 32 cases (10.3%): 22 cases (7.1%) of AVN and 10 cases (3.2%) of FF. Initial valgus tilt>15° (p=0.023), posterior tilt>15° (p=0.012), and screw sliding distance (p=0.037) were significantly associated with FIT. FIT occurred in 7 patients (5.2%) with B1.2.1 fractures and 17 patients (48.6%) with B1.1.2 fractures (p<0.001). The odds of FIT were 17-fold higher in patients with initial valgus and posterior tilts>15° (B1.1.2) compared to patients with <15° of tilt in both planes (B1.2.1).
  
  
  CONCLUSIONS
  The severity of initial deformity predicts AVN and FF in patients with valgus angulated femoral neck fractures. Patients with an initial valgus and posterior tilt>15° are reasonable candidates for primary arthroplasty due to high risk of FIT.
authors: Department of Orthopaedic Surgery, Ajou University School of Medicine, Suwon, South Korea.
authors: Hyung Keun
authors: HK
authors: Song
authors: Department of Orthopaedic Surgery, Yonsei University, Gangnam Severance Hospital, Seoul, South Korea.
authors: Ho June
authors: HJ
authors: Choi
authors: Department of Orthopaedic Surgery, Yonsei University, Gangnam Severance Hospital, Seoul, South Korea. Electronic address: kyang@yuhs.ac.
authors: Kyu Hyun
authors: KH
authors: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D060906:Coxa Valga / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005260:Female; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000379:methods; D017102:Fracture Healing; D006801:Humans; D008297:Male; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome
keywords: Avascular necrosis; Femur neck fracture; Fixation failure; Screw osteosynthesis; Valgus angulated