Randomized clinical study to compare the accuracy of navigated and non-navigated thoracic pedicle screws in deformity correction surgeries

Spine (Phila Pa 1976). 2007 Jan 15;32(2):E56-64. doi: 10.1097/01.brs.0000252094.64857.ab.


Study design: Randomized clinical trial (level I evidence).

Objective: To compare the accuracy of non-navigation and Iso-C based navigation in pedicle screw fixation in thoracic spine deformities.

Summary of background data: Thoracic pedicle screw insertion for spinal deformity correction can be associated with increased pedicle breaches. Iso-C based navigation has been reported to improve the accuracy of pedicle screw placement, but its use in the presence of deformity has not been reported.

Methods: Twenty-seven patients with scoliosis and 6 patients with kyphosis had a total of 478 thoracic pedicle screws. The average Cobb angle was 58.4 degrees +/- 8 degrees (range 50 degrees -80 degrees), and the mean kyphotic angle was 54.6 degrees +/- 4 degrees (range 51 degrees -76 degrees). By random allocation, 17 patients had screw insertion under navigation (242 screws) and 16 under fluoroscopic control (236 screws). The 2 groups were compared for accuracy of screw placement, time for screw insertion, and the number of times the C-arm had to be brought into the field. Two independent blinded observers determined accuracy using postoperative computed tomography assessments.

Results: There were 54 (23%) pedicle breaches in the non-navigation group as compared to only 5 (2%) in the navigation group (P < 0.001). Thirty-eight screws (16%) in the non-navigation group had penetrated the anterior or lateral cortex compared to 2 screws (0.8%) in the navigation group. Average screw insertion time in the non-navigation group was 4.61 +/- 1.05 minutes (range 1.8-6.5) compared to 2.37 +/- 0.72 minutes (range 1.16-4.5) in navigation group (P < 0.01). The C-arm had to be moved into the operation field on an average of 1.5 +/- 0.25 times (range 1-3) per screw. With single screening data, an average of 11.4 pedicles (range 9-14) could be visualized without necessity to bring the C-arm into operating field again.

Conclusions: Iso-C navigation increases accuracy, and reduces surgical time and radiation in thoracic deformity correction surgeries.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Bone Screws*
  • Child
  • Female
  • Fluoroscopy
  • Humans
  • Kyphosis / diagnostic imaging
  • Kyphosis / surgery*
  • Male
  • Middle Aged
  • Postoperative Period
  • Preoperative Care
  • Scoliosis / diagnostic imaging
  • Scoliosis / surgery*
  • Surgery, Computer-Assisted* / instrumentation
  • Thoracic Vertebrae / surgery*
  • Time Factors