title: Direct reduction may need to be considered to avoid postoperative subtype P in patients with an unstable trochanteric fracture: a retrospective study using a multivariate analysis.
abstract: BACKGROUND
  It has recently been reported that the cases with an anterior femoral neck cortex posterior to the distal fragment (subtype P) in the lateral view of a postoperative radiograph have a risk of excessive sliding of lag screws compared to those located anterior to the distal fragment (subtype A) or perfectly continuous to the distal fragment (subtype N) following osteosynthesis for the treatment of a trochanteric fracture. The purpose of this study was to investigate factors that influence the postoperative subtype in the lateral view of radiographs.
  
  
  METHODS
  This study reviewed 136 patients who underwent osteosynthesis using an intramedullary hip nail for the treatment of a trochanteric fracture. A closed reduction was performed in 130 patients (95.6 %), while a direct reduction via a small elevator with a small skin incision was performed in the other six patients (4.4 %). The 136 patients were divided into two groups (subtype P and subtype A or N) based on postoperative radiographs taken of the lateral view. Both clinical and radiological factors were analyzed using the univariate and multivariable analyses.
  
  
  RESULTS
  Thirty-nine patients (29 %) were categorized as subtype P and 97 patients (71 %) were categorized as subtype A or N. A multivariate analysis demonstrated that unstable fractures were associated with a significant risk of postoperative subtype P (Odds ratio: 24.45, P = 0.0024).
  
  
  CONCLUSIONS
  The results of this study suggest that direct reduction via a small elevator with a small skin incision or percutaneous intrafocal pinning may be needed in these cases.
authors.affiliation: Investigation performed at the Department of Orthopaedic Surgery, Shimonoseki City Hospital, 1-13-1 Koyo-cho, Shimonoseki, 750-8520, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kozono
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikemura
authors.forename: Akihisa
authors.initials: A
authors.lastname: Yamashita
authors.forename: Takashi
authors.initials: T
authors.lastname: Harada
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kenzo
authors.initials: K
authors.lastname: Shirasawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D005260:Female; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D006620:Hip Fractures / Q000145:classification / Q000601:surgery*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011184:Postoperative Period; D012189:Retrospective Studies