title: Early Mechanical Failures of the Synthes Variable Angle Locking Distal Femur Plate.
abstract: OBJECTIVE
  To document the high failure rate of a specific implant: the Synthes Variable Angle (VA) Locking Distal Femur Plate.
  
  
  METHODS
  Retrospective.
  
  
  METHODS
  Urban University Level I Trauma Center.
  
  
  METHODS
  All distal femur fractures (OTA/AO 33-A, B, C) treated from March 2011 through August 2013 were reviewed from our institutional orthopaedic trauma registry. Inclusion criteria were fractures treated with a precontoured distal femoral locking plate and age between 18 and 84. Exclusion criteria were fractures treated with intramedullary nails, arthroplasty, non-precontoured plates, dual plating, or screw fixation alone. The population was divided into 3 groups: less invasive stabilization system (LISS) group (n = 21), treated with LISS plates (Synthes, Paoli, PA); locking condylar plates (LCPs) group (n = 10), treated with LCPs (Synthes, Paoli, PA); and VA group (n = 36), treated with VA distal femoral LCPs (Synthes, Paoli, PA). Average age was 54.6 ± 17.5 years.
  
  
  METHODS
  Open reduction internal fixation with one of the above implants was performed.
  
  
  METHODS
  The patients were followed radiographically for early mechanical implant failure defined as loosening of locking screws, loss of fixation, plate bending, or implant failure.
  
  
  RESULTS
  There were no statistically significant differences between groups for age, gender, open fracture, mechanism of injury, or medial comminution. There were 3 failures (14.3%) in group LISS, no failures (0%) in group LCP, and 8 failures (22.2%) in group VA. All 3 failures in group LISS were in A-type fractures (2 periprosthetic) and all failures in group VA were in C-type fractures. When all fractures for all 3 groups were compared for failure rate, there was no statistically significant difference (P = 0.23). However, when only 33-C fractures were compared, there was significantly greater failure rate in the VA group (P = 0.03). The mean time to failure in group VA was 147 days (range 24-401 days) and was significantly earlier (P = 0.034) when compared with group LISS (mean 356 days; range 251-433 days).
  
  
  CONCLUSIONS
  Early mechanical failure with the VA distal femoral locking plate is higher than traditional locking plates (LCP and LISS) for OTA/AO 33-C fractures. We caution practicing surgeons against the use of this plate for metaphyseal fragmented distal femur fractures.
  
  
  METHODS
  Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors: Department of Orthopaedic Surgery, University of Texas Health Science Center at Houston, Houston, TX.
authors: Jason C
authors: JC
authors: Tank
authors: Prism S
authors: PS
authors: Schneider
authors: Elizabeth
authors: E
authors: Davis
authors: Matthew
authors: M
authors: Galpin
authors: Mark L
authors: ML
authors: Prasarn
authors: Andrew M
authors: AM
authors: Choo
authors: John W
authors: JW
authors: Munz
authors: Timothy S
authors: TS
authors: Achor
authors: James F
authors: JF
authors: Kellam
authors: Joshua L
authors: JL
authors: Gary
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001860:Bone Plates / Q000706:statistics & numerical data*; D001863:Bone Screws / Q000706:statistics & numerical data; D004867:Equipment Design; D004868:Equipment Failure / Q000706:statistics & numerical data*; D019544:Equipment Failure Analysis; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D016896:Treatment Outcome; D055815:Young Adult