title: Image guidance shortens the learning curve for K-wire placement - an experimental study.
abstract: BACKGROUND
  Computer assisted systems in orthopaedic trauma depend in most cases on fixed reference markers. This work evaluated a reference-free image-based guidance system. Outcome parameters were the number of trials needed to achieve an optimal wire position, the radiation and procedure time, and the learning curve.
  
  
  METHODS
  Forty artificial proximal femora covered in polyurethane foam were used and randomized in two groups. Each bone was equipped with a target marker at the fovea capitis femoris. Two surgeons each inserted 20 K-wires, 10 with and 10 without assistance from the guidance system. The aim was to bring the tips of the K-wires as close as possible to the target marker. Both procedures were performed under fluoroscopic control. The new guidance system is based on 2D-C-arm images. Following the procedure the result was determined using computed tomography.
  
  
  RESULTS
  The same accuracy (P = 0.34) was achieved with less time (P = 0.0008) and less radiation (P = 0.0002) with the guidance system. However, use of the guidance system did shorten the learning curve of both surgeons, leading to a reduced number of trials (P <0.0001). The learning curve of both surgeons was strongly correlated. From the first trial, the performance of both surgeons while using the guidance system, improved over their performance without the guidance system.
  
  
  CONCLUSIONS
  The guidance system helped to achieve an optimal K-wire position with less radiation and less time. The major advantage is the ability of the guidance system to be integrated into the workflow and the short and flat learning curve.
authors: Institute of Research in Rehabilitation Medicine, Ulm University, Wuhrstrasse 2/1, 88422, Bad Buchau, Germany. kraus@email.de
authors: Michael
authors: M
authors: Kraus
authors: Sebastian
authors: S
authors: Weckbach
authors: Almut
authors: A
authors: Jones
authors: Gert
authors: G
authors: Krischak
authors: Florian
authors: F
authors: Gebhard
authors: Hendrik
authors: H
authors: Schöll
mesh_terms: D001864:Bone Wires / Q000706:statistics & numerical data*; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D059032:Learning Curve; D061646:Operative Time; D019919:Prosthesis Implantation / Q000193:education / Q000379:methods / Q000706:statistics & numerical data; D011859:Radiography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000193:education / Q000379:methods* / Q000706:statistics & numerical data*