Sagittal Cervical Alignment in Adolescent Idiopathic Scoliosis

Mitsuru Yagi; Shingo Iizuka; Atsushi Hasegawa; Narihito Nagoshi; Kanehiro Fujiyoshi; Shinjiro Kaneko; Masakazu Takemitsu; Masanobu Shioda; Masafumi Machida

doi:10.1016/j.jspd.2013.11.002

Sagittal Cervical Alignment in Adolescent Idiopathic Scoliosis

Spine Deform. 2014 Mar;2(2):122-130. doi: 10.1016/j.jspd.2013.11.002. Epub 2014 Mar 5.

Authors

Mitsuru Yagi¹, Shingo Iizuka², Atsushi Hasegawa², Narihito Nagoshi², Kanehiro Fujiyoshi², Shinjiro Kaneko², Masakazu Takemitsu², Masanobu Shioda², Masafumi Machida²

Affiliations

¹ Department of Orthopedic Surgery, National Center for Musculoskeletal Disorders, Murayama Medical Center, 2-37-1 Gakuen, Musashi-Murayama City, Tokyo, Japan. Electronic address: yagiman@gmail.com.
² Department of Orthopedic Surgery, National Center for Musculoskeletal Disorders, Murayama Medical Center, 2-37-1 Gakuen, Musashi-Murayama City, Tokyo, Japan.

PMID: 27927378
DOI: 10.1016/j.jspd.2013.11.002

Abstract

Study design: Retrospective case series of surgically treated adolescent scoliosis patients.

Objectives: To assess the radiographic changes of cervical kyphosis and identify the possible factors affecting postoperative sagittal cervical kyphosis in surgically treated patients with adolescent idiopathic scoliosis.

Summary of background data: Cervical kyphosis is a well-recognized phenomenon in patients with adolescent idiopathic scoliosis. Despite recent reports, the prevalence, radiographic changes, and possible factors affecting postoperative sagittal cervical kyphosis are controversial.

Materials and methods: A retrospective review of a single-center database was performed on 133 consecutive patients with adolescent idiopathic scoliosis treated with long instrumented (more than 5 levels) spine fusion (minimum, 2 years; mean, 3.3 years; range, 2 to 5.5 years). A total of 89 patients met all of the inclusion criteria. Preoperative and postoperative radiographic measurements and patient demographics were investigated.

Results: Postoperative cervical kyphosis was observed in 46 patients. Cobb angle decreased from 48.1° ± 13.1° to 15.4° ± 11.1° at the final follow-up. Cervical kyphosis significantly decreased from 5.5° ± 8.9° preoperatively to -1.5° ± 8.9° at the final follow-up. No difference was observed for T2-T5, T5-T12, lumbar lordosis, sacral slope, pelvic incidence, pelvic tilt, and sagittal vertical axis during the follow-up. Notably, T2 sagittal tilt was significantly increased from preoperatively to the final follow-up. Pearson correlation coefficient test showed a strong correlation between postoperative cervical lordosis and T2 sagittal tilt (r = 0.73; p < .001).

Conclusions: Despite the significant increase of cervical lordosis, 85% of patients still have a kyphotic or less lordotic cervical spine. The strong positive association between cervical lordosis and T2 sagittal tilt suggests that the sagittal cervical alignment of adolescent idiopathic scoliosis patients is closely related to the global sagittal spine balance rather than thoracic kyphosis.

Keywords: Adolescent idiopathic scoliosis; Cervical kyphosis; Complication.