Importance of Distal Fusion Level in Major Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis Treated by Rod Derotation and Direct Vertebral Rotation Following Pedicle Screw Instrumentation

• Published in: Spine (Philadelphia, Pa. 1976) Vol. 42; no. 15; p. E890
• Main Authors: Chang, Dong-Gune, Yang, Jae Hyuk, Suk, Se-Il, Suh, Seung-Woo, Kim, Young-Hoon, Cho, Woojin, Jeong, Yeon-Seok, Kim, Jin-Hyok, Ha, Kee-Yong, Lee, Jung-Hee
• Format: Journal Article
• Language: English
• Published: United States 01.08.2017
• Subjects: Adolescent; Female; Follow-Up Studies; Humans; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - surgery; Male; Pedicle Screws - trends; Retrospective Studies; Rotation; Scoliosis - diagnostic imaging; Scoliosis - surgery; Spinal Fusion - instrumentation; Spinal Fusion - trends; Thoracic Vertebrae - diagnostic imaging; Thoracic Vertebrae - surgery; Treatment Outcome
• ISSN: 1528-1159
• DOI: 10.1097/BRS.0000000000001998

A retrospective comparative study. The aim of this study was to analyze the exact distal fusion level in the treatment of major thoracolumbar and lumbar (TL/L) adolescent idiopathic scoliosis (AIS) using rod derotation (RD) and direct vertebral rotation (DVR) following pedicle screw instrumentation (PSI). Proper determination of distal fusion level is a very important factor in deformity correction and preservation of motion segments in the treatment of major TL/L AIS. AIS patients with major TL/L curves (n = 64) treated by PSI with RD and DVR methods with a minimum 2-year follow-up were divided into AL3 (flexible) and BL3 (rigid) according to the flexibility and rotation by preoperative bending radiographs. There was no significant difference in TL/L (major) curve between the AL3 and BL3 groups postoperatively (P = 0.933) and at the last follow-up (P = 0.144). In addition, there was no significant difference in thoracic (minor) and compensatory (caudal) curve postoperatively (thoracic curve: P = 0.828, compensatory curve: P = 0.976); however, there was a significant difference in compensatory (caudal) curve at the last follow-up (P = 0.041). The overall prevalence of unsatisfactory results was 28.1% (18/64 patients), and the prevalence was 15.2% (7/46) in the AL3 group and 61.1% (11/18) in the BL3 group, which was significantly different (P < 0.05). Lowest instrumented vertebra (LIV) would be selected at L3 (EV) when the curve is flexible; L3 crosses CSVL with a rotation of less than grade II in preoperative bending radiographs. However, if the curve is rigid, LIV should be extended to L4 (EV + 1) in order to prevent the adding-on phenomenon in the treatment of major TL/L AIS using RD and DVR following PSI. 4.