title: Does PFNA II avoid lateral cortex impingement for unstable peritrochanteric fractures?
abstract: BACKGROUND
  Proximal femoral nail antirotation devices (PFNAs) are considered biomechanically superior to dynamic hip screws for treating unstable peritrochanteric fractures and reportedly have a lower complication rate. The PFNA II was introduced to eliminate lateral cortex impingement encountered with the PFNA. However, it is unclear whether the new design in fact avoids lateral cortex impingement without compromising stability of fixation and fracture healing.
  
  
  OBJECTIVE
  We therefore asked whether the PFNA II: (1) eliminates the lateral cortex impingement and fracture displacement experienced with PFNA; and (2) provides stable fracture fixation with a low major complication rate for unstable fractures in European patients.
  
  
  METHODS
  We retrospectively reviewed 108 patients with an unstable peritrochanteric fracture, 58 treated with PFNA and 50 with PFNA II. We compared nail positioning, major and minor complication rates, operative and fluoroscopy time, blood transfused, time to mobilization, hospital stay, fracture union, and Harris hip score. The minimum followup was 12 months (mean, 13 months; range, 12-18 months).
  
  
  RESULTS
  In the PFNA II group we encountered no impingement on the lateral cortex and no patients with lateral fragment or loss of reduction at insertion, whereas with the PFNA group, we had 10 and five cases, respectively. Fracture union occurred in all patients treated with PFNA II without mechanical failures. PFNA II cases were associated with a slightly shorter surgical time than PFNA cases (23 minutes versus 27 minutes, respectively).
  
  
  CONCLUSIONS
  PFNA II avoided lateral cortex impingement experienced with PFNA, providing fast and stable fixation of the unstable peritrochanteric fractures.
  
  
  METHODS
  Level III, retrospective comparative study. See Guidelines for Authors for a complete description of levels of evidence.
authors: 4th Department of Orthopaedics and Traumatology, KAT Hospital, 2 Nikis Street, 145 61 Athens, Greece. gmacheras@gmail.com
authors: George A
authors: GA
authors: Macheras
authors: Stefanos D
authors: SD
authors: Koutsostathis
authors: Spyridon
authors: S
authors: Galanakos
authors: Konstantinos
authors: K
authors: Kateros
authors: Stamatios A
authors: SA
authors: Papadakis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001858:Bone Nails; D005260:Female; D005593:Fracture Fixation, Internal / Q000009:adverse effects* / Q000295:instrumentation; D017102:Fracture Healing / Q000502:physiology; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies