title: Arthroscopic mosaicplasty for osteochondral lesions of the knee: computer-assisted navigation versus freehand technique.
abstract: OBJECTIVE
  The purpose of this study was to compare a freehand arthroscopic approach versus mosaicplasty for treatment of osteochondral lesions of the knee with a navigated arthroscopic technique.
  
  
  METHODS
  Four whole cadaveric lower limbs were used. A conventional navigation system was used in combination with an autologous osteochondral graft transplantation system (Osteochondral Autograft Transfer System [OATS]; Arthrex, Naples, FL). The congruity of the articular surface was measured with the navigation probe to detect any difference between the surface created by the grafts and the surface of the femoral condyle surrounding them. The angle relates to a line perpendicular to the articular surface. This line is made by the cutting instrument for graft harvesting and insertion and the articular surface.
  
  
  RESULTS
  The mean angle of graft harvest was 3.4° (range, 0° to 10°) in the navigated group versus 14.8° (range, 6° to 26°) in the freehand group (P < .0003). The mean angle for recipient-site coring was 1.5° (range, 0° to 5°) in the navigated group versus 12.6° (range, 4° to 17°) in the freehand group (P < .0003). The mean angle of graft placement was 2° (range, 1° to 5°) in the navigated group versus 10.8° (range, 5° to 15°) in the freehand group (P = .0002). The mean protrusion height of the plug was 0.23 mm (range, 0.1 to 0.5 mm; SD, 0.16) in the navigated group versus 0.34 mm (range, 0.0 to 0.7 mm; SD, 0.25) in the freehand group (P = .336).
  
  
  CONCLUSIONS
  Computer-assisted arthroscopic mosaicplasty for treatment of osteochondral lesions in the cadaveric model presented in this study allows permanent visualization of the angle of recipient-site preparation, the depth of the donor plug and the recipient plug, and the angle of insertion of the graft at the recipient site.
  
  
  CONCLUSIONS
  This study shows evidence of potentially greater precision and reproducibility of navigated arthroscopic mosaicplasty when compared with an arthroscopic freehand technique in a cadaveric model. However, true clinical outcome benefit will only be elucidated upon performance of appropriate clinical studies.
authors.affiliation: Clinic of Orthopaedics and Traumatology, University of Udine, Udine, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Di Benedetto
authors.forename: Mustafa
authors.initials: M
authors.lastname: Citak
authors.forename: Daniel
authors.initials: D
authors.lastname: Kendoff
authors.forename: Padhraig F
authors.initials: PF
authors.lastname: O'Loughlin
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pearle
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Koulalis
mesh_terms: D001182:Arthroscopy; D002102:Cadaver; D002358:Cartilage, Articular / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted; D014182:Transplantation, Autologous; D019737:Transplants