STUDY DESIGN: Retrospective study. PURPOSE: We compared the accuracy of O-arm-based navigation with computed tomography (CT)-based navigation in scoliotic surgery. OVERVIEW OF LITERATURE: No previous reports comparing the results of O-arm-based navigation with conventional CT-based navigation in scoliotic surgery have been published. METHODS: A total of 222 pedicle screws were implanted in 29 patients using CT-based navigation (group C) and 416 screws were implanted in 32 patients using O-arm-based navigation (group O). Postoperative CT was performed to assess the screw accuracy, using the established Neo classification (grade 0: no perforation, grade 1: perforation <2 mm, grade 2: perforation > or =2 and <4, and grade 3: perforation > or =4 mm). RESULTS: In group C, 188 (84.7%) of the 222 pedicle screw placements were categorized as grade 0, 23 (10.4%) were grade 1, 11 (5.0%) were grade 2, and 0 were grade 3. In group O, 351 (84.4%) of the 416 pedicle screw placements were categorized as grade 0, 52 (12.5%) were grade 1, 13 (3.1%) were grade 2, and 0 were grade 3. Statistical analysis showed no significant difference in the prevalence of grade 2.3 perforations between groups C and O. The time to position one screw, including registration, was 10.9+/-3.2 minutes in group C, but was significantly decreased to 5.4+/-1.1 minutes in group O. CONCLUSIONS: O-arm-based navigation facilitates pedicle screw insertion as accurately as conventional CT-based navigation. The use of O-arm-based navigation successfully reduced the time, demonstrating advantages in the safety and accuracy of pedicle screw placement for scoliotic surgery.
Classification ; Humans ; Prevalence ; Retrospective Studies ; Scoliosis* ; Spine ; Surgery, Computer-Assisted

OBJECTIVE: To investigate the effectiveness of incentive spirometry on respiratory motion in healthy subjects using cine breathing magnetic resonance imaging (MRI). METHODS: Ten non-smoking healthy subjects without any history of respiratory disease were studied. Subjects were asked to perform pulmonary training using incentive spirometry every day for two weeks. To assess the effectiveness of this training, pulmonary function tests and cine breathing MRI were performed before starting pulmonary training and two weeks after its completion. RESULTS: After training, there were significant improvements in vital capacity (VC) from 3.58+/-0.8 L to 3.74+/-0.8 L and in %VC from 107.4+/-10.8 to 112.1+/-8.2. Significant changes were observed in the right diaphragm motion, right chest wall motion, and left chest wall motion, which were increased from 55.7+/-9.6 mm to 63.4+/-10.2 mm, from 15.6+/-6.1 mm to 23.4+/-10.4 mm, and from 16.3+/-7.6 mm to 22.0+/-9.8 mm, respectively. CONCLUSION: Two weeks of training using incentive spirometry provided improvements in pulmonary function and respiratory motion, which suggested that incentive spirometry may be a useful preoperative modality for improving pulmonary function during the perioperative period.
Diaphragm ; Magnetic Resonance Imaging* ; Motivation* ; Perioperative Period ; Respiration* ; Respiratory Function Tests ; Spirometry* ; Thoracic Wall ; Vital Capacity