title: Thoracic pedicle screw insertion in scoliosis using posteroanterior C-arm rotation method.
abstract: OBJECTIVE
  Previous researches have emphasized the importance and difficulties in accurate thoracic pedicle screw insertion in scoliosis patients. However, there has been no report on accuracy of the insertion using posteroanterior C-arm fluoroscopy rotated to allow en face visualization of the pedicle in humans. This study aimed to evaluate the accuracy of the thoracic pedicle screw insertion technique using a C-arm fluoroscopy rotation method for the treatment of scoliosis.
  
  
  METHODS
  Between October 1997 and September 2005, 33 scoliosis patients who underwent surgical treatment with a total of 410 screws were analyzed. Eleven were male, 22 female and the mean age was 13.4 years. The mean preoperative Cobb angle was 59.7 degrees. Screws were inserted using the C-arm rotation method; screw positions were evaluated with postoperative computed tomography scans.
  
  
  RESULTS
  The mean preoperative Cobb angle of 59.7 degrees was corrected to 18.9 degrees (range, 3 to 45 degrees) in the coronal plane (mean correction rate 68%). Postoperative computed tomography scans demonstrated 48 screws penetrated the medial (9 screws) or lateral (39 screws) pedicle cortex with a mean distance of 3.1 and 3.6 mm, respectively. No screws penetrated the inferior or superior cortex in the sagittal plane.
  
  
  CONCLUSIONS
  Thoracic pedicle screw insertion in scoliosis patients using the posteroanterior C-arm rotation method allows en face visualization of both pedicles by rotating the C-arm to compensate for the rotational deformity, making it a practical, simple and safe method.
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center, College of Medicine, Ulsan University, Seoul, Korea. cslee@amc.seoul.kr
authors.forename: Choon-Sung
authors.initials: CS
authors.lastname: Lee
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kim
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Ahn
authors.forename: Yung-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Kyeong-Il
authors.initials: KI
authors.lastname: Jeong
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D001863:Bone Screws / Q000592:standards* / Q000639:trends; D002648:Child; D005260:Female; D005471:Fluoroscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D016268:Internal Fixators / Q000592:standards* / Q000639:trends; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome