Bang-Ping Qian1, Yun-Peng Zhang2, Mu Qiao3, Yong Qiu2, Sai-Hu Mao2. 1. Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China. Electronic address: qianbangping@163.com. 2. Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China. 3. Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China; Southeast University Medical School, Nanjing, China.
Abstract
OBJECTIVE: To evaluate the accuracy and safety of freehand pedicle screw placement in surgical correction for thoracolumbar kyphosis caused by ankylosing spondylitis (AS). METHODS: We retrospectively reviewed 266 consecutive patients with AS who underwent osteotomy for kyphosis correction with freehand screw insertion from January 1998 to April 2015 at our institution. A total of 2314 pedicle screws in 158 patients with AS with postoperative computed tomography scans were included in the study. Postoperative computed tomography was performed to classify accuracy of screws, using the established Gertbein classification (grade 0: no perforation, grade 1: perforation <2 mm, grade 2: perforation between 2 and 4 mm, and grade 3: perforation >4 mm). Patients were divided into 2 groups according to coronal Cobb angle: group A (n = 21, Cobb angle ≥10°), group B (n = 137, Cobb angle <10°). RESULTS: Among the 2314 pedicle screws, 2168 pedicle screw placements were categorized as grade 0, 71 were grade 1, 51 were grade 2, and 24 were grade 3. Breaches occurred more frequently in L1-S1 than the thoracic spine (7.1% and 5.4%, respectively). T5 (25.0%) and S1 (17.7%) experienced the greatest breach rate, whereas T8, L1, and L3 had the lowest breach rate. The breach rate of group A was greater than that of group B (7.9% vs. 6.1%). None of the breaches resulted in either neurologic deficits or vascular complications. CONCLUSIONS: Freehand pedicle screw placement can be performed safely with acceptable breach rate in patients with AS and thoracolumbar kyphosis.
OBJECTIVE: To evaluate the accuracy and safety of freehand pedicle screw placement in surgical correction for thoracolumbar kyphosis caused by ankylosing spondylitis (AS). METHODS: We retrospectively reviewed 266 consecutive patients with AS who underwent osteotomy for kyphosis correction with freehand screw insertion from January 1998 to April 2015 at our institution. A total of 2314 pedicle screws in 158 patients with AS with postoperative computed tomography scans were included in the study. Postoperative computed tomography was performed to classify accuracy of screws, using the established Gertbein classification (grade 0: no perforation, grade 1: perforation <2 mm, grade 2: perforation between 2 and 4 mm, and grade 3: perforation >4 mm). Patients were divided into 2 groups according to coronal Cobb angle: group A (n = 21, Cobb angle ≥10°), group B (n = 137, Cobb angle <10°). RESULTS: Among the 2314 pedicle screws, 2168 pedicle screw placements were categorized as grade 0, 71 were grade 1, 51 were grade 2, and 24 were grade 3. Breaches occurred more frequently in L1-S1 than the thoracic spine (7.1% and 5.4%, respectively). T5 (25.0%) and S1 (17.7%) experienced the greatest breach rate, whereas T8, L1, and L3 had the lowest breach rate. The breach rate of group A was greater than that of group B (7.9% vs. 6.1%). None of the breaches resulted in either neurologic deficits or vascular complications. CONCLUSIONS: Freehand pedicle screw placement can be performed safely with acceptable breach rate in patients with AS and thoracolumbar kyphosis.
Authors: Andrew Hersh; Smruti Mahapatra; Carly Weber-Levine; Tolulope Awosika; John N Theodore; Hesham M Zakaria; Ann Liu; Timothy F Witham; Nicholas Theodore Journal: HSS J Date: 2021-07-14