title: Accuracy analysis of a novel electromagnetic navigation procedure versus a standard minimally invasive method for arthroscopically assisted acromioclavicular joint reconstructions.
abstract: OBJECTIVE
  The aim of this cadaveric study was to evaluate the accuracy, feasibility, and operation time of a novel electromagnetic navigation system (ENS) and procedure for transclavicular-transcoracoid tunnel placement compared with a standard minimally invasive (SMI) reconstruction method for minimally invasive arthroscopically assisted anatomic acromioclavicular joint reconstruction.
  
  
  METHODS
  Ten arthroscopically assisted electromagnetic-navigated transclavicular-transcoracoid drilling procedures and 10 SMI procedures were performed on 10 human cadavers using 2 TightRope reconstructions (Arthrex, Naples, FL) for each site. Postoperative computed tomography scans were acquired to determine tunnel placement accuracy. Optimal coracoid tunnel placement was defined according to the anatomic insertions of the trapezoid and conoid ligaments with the oblong button placed in a center-base position at the coracoid undersurface without cortical breach or fracture. Both reconstruction procedures were performed without fluoroscopy.
  
  
  RESULTS
  Successful tunnel placement was accomplished in 98.8% using the ENS method and in 83.8% using the SMI procedure (P = .087). The mean overall operation time was 28.5 ± 6.6 minutes for the ENS method and 35.2 ± 3.9 minutes for the SMI method (P = .012). The ENS procedure required no directional readjustments or restarts. Drill misguidance with subsequent cortical breach occurred twice in the SMI group. In both groups no fractures were documented.
  
  
  CONCLUSIONS
  In this descriptive laboratory study, both the ENS and the SMI techniques achieved the desired anatomic reconstruction. Compared with the SMI method, the ENS procedure showed higher accuracy, required a shorter operation time, and was associated with no complications.
  
  
  CONCLUSIONS
  Length of surgery, drilling accuracy, and reduction of radiation exposure in acromioclavicular joint reconstruction procedures affect the safety of both patients and surgeons.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: mi.hoffmann@uke.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmann
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Schroeder
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Hartel
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Korecki
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Rueger
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jacob V
authors.initials: JV
authors.lastname: Nüchtern
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lehmann
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jan P
authors.initials: JP
authors.lastname: Petersen
mesh_terms: D000173:Acromioclavicular Joint / Q000601:surgery*; D001178:Arthroplasty / Q000379:methods*; D001182:Arthroscopy; D002102:Cadaver; D055590:Electromagnetic Phenomena; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012782:Shoulder / Q000000981:diagnostic imaging; D013997:Time Factors; D014057:Tomography, X-Ray Computed