title: Reoperation rate after internal fixation of intertrochanteric femur fractures with the percutaneous compression plate: what are the risk factors?
abstract: OBJECTIVE
  The aim was this study was to analyze the risk factors for reoperation after internal fixation of intertrochanteric fractures of the femur using the percutaneous compression plate (PCCP).
  
  
  METHODS
  This was a retrospective cohort study.
  
  
  METHODS
  The study was conducted at the University Hospital.
  
  
  METHODS
  Patients with intertrochanteric femur fractures who underwent internal fixation with a PCCP were included in this study. We investigated potential risk factors such as age, gender, body mass index, comorbidities of the patients (American Society of Anesthetist classification), type of fracture (AO/OTA classification), experience of the surgeons (in terms of the number of surgical procedures with the PCCP device), tip-apex distance (TAD), and operation time. The procedures were performed by 10 surgeons. Logistic regression was used to assess potential predictors for the need of reoperation.
  
  
  RESULTS
  Of the 96 patients with 96 intertrochanteric fractures, 8 underwent reoperation due to local complications (8.3%). The most frequent complication was complete or imminent cutting out of the upper cervical screw (N = 5; 5.2%). Five of the 8 risk factors that were associated with reoperation in the initial univariable analyses with a P value of <0.20 were retained in a multivariable logistic regression model, including, age, body mass index, TAD, experience of the surgeons, and operation time. Of these, only the factor TAD proved to be a significant predictor for reoperation (P = 0.027, odds ratio = 1.089, 95% confidence interval 1.01-1.175).
  
  
  CONCLUSIONS
  Our data show that the surgeon-related risk factors (number of operations, operation time, TAD) seem to be more relevant for the reoperation rate after internal fixation with the PCCP device when compared with the patient-related risk factors. This finding indicates a substantial learning curve for this technically demanding procedure.
  
  
  METHODS
  Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedics and Trauma Surgery, RWTH Aachen University †Institute of Medical Statistics, RWTH Aachen University, Aachen, Germany. bschmidt-rohlfing@gmx.de
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt-Rohlfing
authors.forename: Nicole
authors.initials: N
authors.lastname: Heussen
authors.forename: Matthias
authors.initials: M
authors.lastname: Knobe
authors.forename: Roman
authors.initials: R
authors.lastname: Pfeifer
authors.forename: Jason R
authors.initials: JR
authors.lastname: Kaneshige
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Pape
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001860:Bone Plates / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D005593:Fracture Fixation, Internal / Q000295:instrumentation* / Q000706:statistics & numerical data*; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D015995:Prevalence; D011361:Professional Competence / Q000706:statistics & numerical data; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D016896:Treatment Outcome