ABSTRACT
Purpose: This study evaluated a practical, safe and accurate method of thoracic pedicle screw insertion for the surgical treatment of scoliosis using the posteroanterior C-arm fluoroscopy rotation method. Materials and Methods: A total of 611 thoracic pedicle screws were inserted in 45 patients using the posteroanterior (PA) C-arm rotation method. CT scans were taken postoperatively in the transverse and sagittal sections to evaluate the pedicle screw placement. Results: A mean preoperative curve of 57.7o was corrected to 17.1o (range, 3o-45o) in the coronal plane. The postoperative CT scans revealed that 10 screws (1.6%) had penetrated the medial cortex by a mean distance of 3.0 mm and 56 screws (9.2%) penetrated the lateral cortex by a mean distance of 3.5 mm. No screw penetrated the inferior or superior cortex in the sagittal plane. However, 21 screws (3.4%) penetrated the anterior cortex. No neurological or vascular complications were encountered, and none of the screws required replacement. Conclusion: Thoracic pedicle screw insertion in scoliosis patients using the posteroanterior C-arm rotation method is a practical, simple and safe technique that allows the en face visualization of both pedicles by rotating the C-arm to compensate for the rotational deformity.
Subject(s)
Humans , Congenital Abnormalities , Fluoroscopy , Scoliosis , Tomography, X-Ray ComputedABSTRACT
STUDY DESIGN: A prospective study of the accuracy of thoracic pedicle screws inserted in scoliotic patients. OBJECTIVES: To evaluate and present a practical, safe and accurate method for thoracic pedicle screw insertion in the surgical treatment of scoliosis using the posteroanterior c-arm fluoroscopy rotating method. SUMMARY OF LITERATURE REVIEW: Previous studies have emphasized the clinical importance, yet difficulty, of accurate thoracic pedicle screw insertion in scoliotic patients. Three-dimensional alterations in the pedicle orientation of scoliotic patients makes the accurate insertion challenging. No reports exist on the accuracy and benefits of posteroanterior c-arm fluoroscopy, which is rotated to allow visualization from en face, in real patients. MATERIALS AND METHODS: A total of 350 thoracic pedicle screws were inserted in 29 patients, including 24 with idiopathic scoliosis, using the posteroanterior (PA) c-arm rotation method. The smallest patient weighed 14 kg, and the next smallest 17 kg. The average preoperative curve was 60.9 degrees(range, 45 degrees~101 degrees). CT scans were taken, postoperatively, in the transverse and sagittal sections to evaluate the pedicle screw placement. RESULTS: The mean preoperative curve of 60.9 degrees was corrected to 15.4 degrees(range, 3 degrees~45 degrees) in the coronal plane, a correction of 74.7%. A mean of 12.1 thoracic screws were inserted per patient. On analysis of the postoperative CT scans, 39(11.1%) of the 350 screws penetrated the medial or lateral pedicle cortices, 8(2.3%) into the medial cortex and 31(8.9%) into the lateral cortex, by mean distances of 3.3 and 3.6 mm, respectively. No screws penetrated the inferior or superior cortices in the sagittal plane, but 16(4.6%) penetrated the anterior cortex. No neurological or vascular complications were encountered, and none of the screws required subsequent replacement. CONCLUSIONS: Thoracic pedicle screw insertion in scoliotic patients, using a posteroanterior c-arm rotation method, allows the en face visualization of both pedicles by rotating the c-arm to compensate for rotational deformity, which makes it a practical, simple and safe method.