title: Arthroscopically assisted retrograde drilling for osteochondritis dissecans (OCD) lesions of the knee.
abstract: OBJECTIVE
  Accurate retrograde drilling for osteochondritis dissecans lesions remains technically challenging. A novel, radiation-free method using an electromagnetic guidance system was developed, and its feasibility and accuracy for retrograde drilling procedures evaluated in an experimental setting.
  
  
  METHODS
  Sixteen arthroscopically assisted, electromagnetically guided retrograde drilling procedures were performed in 4 human cadaveric knee joints. Therefore, two artificial cartilage lesions were set consecutively on each condyle. Final drill bit position was documented in two planes using fluoroscopy. Subsequently, drilling accuracy was measured in terms of distance from the final position of the drill bit to the articular cartilage surface (D1), and distance between the tip of the drill bit to the centre of the cartilage lesion on the articular cartilage surface (D2). All procedures were timed using a stopwatch.
  
  
  RESULTS
  Successful retrograde drilling was accomplished in all 16 cases. The overall mean time for the retrograde drilling procedures was 361.6 ± 34.7 s. Mean D1 was 2.2 ± 0.5 mm; mean D2 was 0.8 ± 0.7 mm. No complications occurred.
  
  
  CONCLUSIONS
  The novel electromagnetic guidance system used in this study showed accurate targeting results, required no radiation, was associated with no complications and demonstrated user-friendliness.
  
  
  METHODS
  II.
authors.affiliation: Department of Trauma, Hand- and Reconstructive Surgery, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany. mi.hoffmann@uke.de
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmann
authors.forename: Malte
authors.initials: M
authors.lastname: Schröder
authors.forename: Jan Philipp
authors.initials: JP
authors.lastname: Petersen
authors.forename: Alexander Simon
authors.initials: AS
authors.lastname: Spiro
authors.forename: Michael
authors.initials: M
authors.lastname: Kammal
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lehmann
authors.forename: Johannes Maria
authors.initials: JM
authors.lastname: Rueger
authors.forename: Andreas Hermann
authors.initials: AH
authors.lastname: Ruecker
mesh_terms: D001182:Arthroscopy / Q000379:methods*; D002102:Cadaver; D004574:Electromagnetic Fields; D005471:Fluoroscopy; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D010008:Osteochondritis Dissecans / Q000601:surgery*; D012984:Software