title: Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques.
abstract: BACKGROUND
  With the advances and improvement of computer-assisted surgery devices, computer-guided pedicle screws insertion has been applied to the lumbar, thoracic and cervical spine. The purpose of the present study was to perform a systematic review of all available prospective evidence regarding pedicle screw insertion techniques in the thoracic and lumbar human spine.
  
  
  METHODS
  We considered all prospective in vivo clinical studies in the English literature that assessed the results of different pedicle screw placement techniques (free-hand technique, fluoroscopy guided, computed tomography (CT)-based navigation, fluoro-based navigation). MEDLINE, OVID, and Springer databases were used for the literature search covering the period from January 1950 until May 2010.
  
  
  RESULTS
  26 prospective clinical studies were eventually included in the analysis. These studies included in total 1,105 patients in which 6,617 screws were inserted. In the studies using free-hand technique, the percentage of the screws fully contained in the pedicle ranged from 69 to 94%, with the aid of fluoroscopy from 28 to 85%, using CT navigation from 89 to 100% and using fluoroscopy-based navigation from 81 to 92%. The screws positioned with free-hand technique tended to perforate the cortex medially, whereas the screws placed with CT navigation guidance seemed to perforate more often laterally.
  
  
  CONCLUSIONS
  In conclusion, navigation does indeed exhibit higher accuracy and increased safety in pedicle screw placement than free-hand technique and use of fluoroscopy.
authors: Department of Orthopaedic Surgery and Traumatology, School of Medicine, University of Ioannina, Pantazidi Street 11, 45221 Ioannina, Epirus, Greece. idgelalis@gmail.com
authors: Ioannis D
authors: ID
authors: Gelalis
authors: Nikolaos K
authors: NK
authors: Paschos
authors: Emilios E
authors: EE
authors: Pakos
authors: Angelos N
authors: AN
authors: Politis
authors: Christina M
authors: CM
authors: Arnaoutoglou
authors: Athanasios C
authors: AC
authors: Karageorgos
authors: Avraam
authors: A
authors: Ploumis
authors: Theodoros A
authors: TA
authors: Xenakis
mesh_terms: D001863:Bone Screws; D005471:Fluoroscopy; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D019637:Orthopedic Procedures / Q000379:methods*; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted; D013904:Thoracic Vertebrae / Q000601:surgery*