title: Accuracy of CT-assisted pedicle screw placement after CT-controlled, presurgical guide wire implantation in traumatic and pathological fractures in the thoracic spine.
abstract: BACKGROUND
  The aim of this study was to evaluate the accuracy of pedicle screw placement after computed tomography (CT)-assisted positioning of guide wires and subsequent insertion of transpedicular screws in particularly narrow pedicles in the thoracic spine. Transpedicular pedicle screw placement has been commonly used for a number of decades. However, a significant number of malpositioned screws still occur, especially in the thoracic spine, potentially correlating with relevant complications, e.g., neurological deterioration.
  
  
  METHODS
  A retrospective analysis was performed after CT-assisted and -controlled implantation of guide wires into the pedicle. A total of 39 patients underwent dorsal spondylodesis using two different internal fixation systems, i.e., with a cannulated or a solid screw design. The postoperative screw position was evaluated with CT scans in three planes in a total of 254 screws.
  
  
  RESULTS
  The number of the screws inserted at each level were as follows (total n = 326): T1, n = 8; T2, n = 26; T3, n = 26; T4, n = 36; T5, n = 50; T6, n = 37; T7, n = 38; T8, n = 32; T9, n = 24; T10, n = 18; T11, n = 10; T12, n = 6. Indications for the operative treatment were fractures, tumors, and infectious diseases. A total of 254 screws inserted were evaluated by CT scan in order to determine the screw position inside the pedicle and potential perforation of the pedicle wall. The overall rate of pedicle wall perforation was 7.5%, including 1.2% perforations of the medial wall. A significant correlation between the perforation rate and the type of fixation system in favor of the cannulated system was found (P = 0.033). During the study, no revision surgery due to screw misplacement was necessary. None of the treated patients showed neurological deterioration after screw implantation during the presented study.
  
  
  CONCLUSIONS
  The CT-assisted pedicle screw implantation procedure using guide wires implanted prior to surgery is an accurate, reliable, and safe method for dorsal spondylodesis in the treatment of a variety of spinal instabilities, including fractures, tumors, and infections.
authors.affiliation: Department of Trauma, Hand, and Reconstructive Surgery, University Hospital Frankfurt/Main, Johann Wolfgang Goethe University, Frankfurt/Main, Germany.|Department of Trauma and Orthopedics, Klinikum Pforzheim, Kanzlerstraße 2-6, 75175, Pforzheim, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Ploss
authors.affiliation: Department of Trauma, Hand, and Reconstructive Surgery, University Hospital Frankfurt/Main, Johann Wolfgang Goethe University, Frankfurt/Main, Germany. bernd.maier@klinikum-pforzheim.de.|Department of Trauma and Orthopedics, Klinikum Pforzheim, Kanzlerstraße 2-6, 75175, Pforzheim, Germany. bernd.maier@klinikum-pforzheim.de.
authors.forename: B
authors.initials: B
authors.lastname: Maier
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt/Main, Johann Wolfgang Goethe University, Frankfurt/Main, Germany.
authors.forename: M G
authors.initials: MG
authors.lastname: Mack
authors.affiliation: Department of Trauma, Hand, and Reconstructive Surgery, University Hospital Frankfurt/Main, Johann Wolfgang Goethe University, Frankfurt/Main, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Marzi
keywords: Pedicle screws; Spinal fractures; Spine surgery; Stabilization; Thoracic spine; Transpedicular; Traumatic injuries
references.citation: Spine (Phila Pa 1976). 1996 Feb 1;21(3):264-70
references.pmid: 8742200
references.citation: Surg Neurol. 1997 Dec;48(6):566-74
references.pmid: 9400637
references.citation: J Bone Joint Surg Am. 1962 Jun;44-A:591-610
references.pmid: 14036052
references.citation: Spine (Phila Pa 1976). 1997 Feb 1;22(3):233-8
references.pmid: 9051883
references.citation: Spine (Phila Pa 1976). 2001 Feb 15;26(4):360-4
references.pmid: 11224882
references.citation: Unfallchirurg. 2001 Nov;104(11):1076-81
references.pmid: 11760340
references.citation: Paraplegia. 1991 Nov;29(9):573-81
references.pmid: 1787981
references.citation: J Bone Joint Surg Am. 1995 Aug;77(8):1193-9
references.pmid: 7642664
references.citation: Orthopade. 1999 May;28(5):424-31
references.pmid: 10394601
references.citation: Reconstr Surg Traumatol. 1976;15:2-16
references.pmid: 968155
references.citation: Spine (Phila Pa 1976). 1987 Nov;12(9):882-900
references.pmid: 3441835
references.citation: Spine (Phila Pa 1976). 2006 May 20;31(12):E355-8
references.pmid: 16721279
references.citation: Spine (Phila Pa 1976). 1996 Jun 1;21(11):1320-4
references.pmid: 8725923
references.citation: Clin Orthop Relat Res. 1980 Jul-Aug;(150):137-53
references.pmid: 7428211
references.citation: Paraplegia. 1969 Nov;7(3):179-92
references.pmid: 5360915
references.citation: Spine (Phila Pa 1976). 1998 May 1;23(9):1065-8
references.pmid: 9589548
references.citation: Spine (Phila Pa 1976). 2003 Oct 15;28(20):2324-30
references.pmid: 14560078
references.citation: Spine (Phila Pa 1976). 2001 Sep 15;26(18):2049-57
references.pmid: 11547207
references.citation: Spine (Phila Pa 1976). 1990 Jan;15(1):11-4
references.pmid: 2326693
references.citation: Spine (Phila Pa 1976). 2002 Nov 15;27(22):2467-71
references.pmid: 12435976
references.citation: Spine (Phila Pa 1976). 2001 Nov 1;26(21):2340-6
references.pmid: 11679819
references.citation: Spine (Phila Pa 1976). 1995 Jun 15;20(12 ):1399-405
references.pmid: 7676339
references.citation: Eur Spine J. 1997;6(1):19-24
references.pmid: 9093823
references.citation: Spine (Phila Pa 1976). 2005 Jun 15;30(12 ):E326-31
references.pmid: 15959355
references.citation: Spine (Phila Pa 1976). 2004 Feb 1;29(3):333-42; discussion 342
references.pmid: 14752359
references.citation: Spine (Phila Pa 1976). 1999 Jan 15;24(2):114-9
references.pmid: 9926379
references.citation: Clin Anat. 2005 Sep;18(6):404-8
references.pmid: 16015613