Sagittal alignment of the cervical spine in the setting of adolescent idiopathic scoliosis.J Neurosurg Spine. 2018 Nov 01; 29(5):506-514.JN
Abstract
OBJECTIVE
The goal of this study was to investigate the impact of thoracic and lumbar alignment on cervical alignment in patients with adolescent idiopathic scoliosis (AIS).METHODS
Eighty-one patients with AIS who had a Cobb angle > 40° and full-length spine radiographs were included. Radiographs were analyzed using dedicated software to measure pelvic parameters (sacral slope [SS], pelvic incidence [PI], pelvic tilt [PT]); regional parameters (C1 slope, C0-C2 angle, chin-brow vertical angle [CBVA], slope of line of sight [SLS], McRae slope, McGregor slope [MGS], C2-7 [cervical lordosis; CL], C2-7 sagittal vertical axis [SVA], C2-T3, C2-T3 SVA, C2-T1 Harrison measurement [C2-T1 Ha], T1 slope, thoracic kyphosis [TK], lumbar lordosis [LL], and PI-LL mismatch); and global parameters (SVA). Patients were stratified by their lumbar alignment into hyperlordotic (LL > 59.7°) and normolordotic (LL 39.3° to 59.7°) groups and also, based on their thoracic alignment, into hypokyphotic (TK < -33.1°) and normokyphotic (TK -33.1° to -54.9°) groups. Finally, they were grouped based on their global alignment into either an anterior-aligned group or a posterior-aligned group.RESULTS
The lumbar hyperlordotic group, in comparison to the normolordotic group, had a significantly larger LL, SS, PI (all p < 0.001), and TK (p = 0.014) and a significantly smaller PI-LL mismatch (p = 0.001). Lumbar lordosis had no influence on local cervical parameters.The thoracic hypokyphotic group had a significantly larger PI-LL mismatch (p < 0.002) and smaller T1 slope (p < 0.001), and was significantly more posteriorly aligned than the normokyphotic group (-15.02 ± 8.04 vs 13.54 ± 6.17 [mean ± SEM], p = 0.006). The patients with hypokyphotic AIS had a kyphotic cervical spine (cervical kyphosis [CK]) (p < 0.001). Furthermore, a posterior-aligned cervical spine in terms of C2-7 SVA (p < 0.006) and C2-T3 SVA (p < 0.001) was observed in the thoracic hypokyphotic group.Comparing patients in terms of global alignment, the posterior-aligned group had a significantly smaller T1 slope (p < 0.001), without any difference in terms of pelvic, lumbar, and thoracic parameters when compared to the anterior-aligned group. The posterior-aligned group also had a CK (-9.20 ± 1.91 vs 5.21 ± 2.95 [mean ± SEM], p < 0.001) and a more posterior-aligned cervical spine, as measured by C2-7 SVA (p = 0.003) and C2-T3 SVA (p < 0.001).CONCLUSIONS
Alignment of the cervical spine is closely related to thoracic curvature and global alignment. In patients with AIS, a hypokyphotic thoracic alignment or posterior global alignment was associated with a global cervical kyphosis. Interestingly, upper cervical and cranial parameters were not statistically different in all investigated groups, meaning that the upper cervical spine was not recruited for compensation in order to maintain a horizontal gaze.Links
MeSH
Pub Type(s)
Journal Article
Language
eng
PubMed ID
30141764
Citation
Akbar, Michael, et al. "Sagittal Alignment of the Cervical Spine in the Setting of Adolescent Idiopathic Scoliosis." Journal of Neurosurgery. Spine, vol. 29, no. 5, 2018, pp. 506-514.
Akbar M, Almansour H, Lafage R, et al. Sagittal alignment of the cervical spine in the setting of adolescent idiopathic scoliosis. J Neurosurg Spine. 2018;29(5):506-514.
Akbar, M., Almansour, H., Lafage, R., Diebo, B. G., Wiedenhöfer, B., Schwab, F., Lafage, V., & Pepke, W. (2018). Sagittal alignment of the cervical spine in the setting of adolescent idiopathic scoliosis. Journal of Neurosurgery. Spine, 29(5), 506-514. https://doi.org/10.3171/2018.3.SPINE171263
Akbar M, et al. Sagittal Alignment of the Cervical Spine in the Setting of Adolescent Idiopathic Scoliosis. J Neurosurg Spine. 2018 Nov 1;29(5):506-514. PubMed PMID: 30141764.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR
T1 - Sagittal alignment of the cervical spine in the setting of adolescent idiopathic scoliosis.
AU - Akbar,Michael,
AU - Almansour,Haidara,
AU - Lafage,Renaud,
AU - Diebo,Bassel G,
AU - Wiedenhöfer,Bernd,
AU - Schwab,Frank,
AU - Lafage,Virginie,
AU - Pepke,Wojciech,
PY - 2017/12/04/received
PY - 2018/03/14/accepted
PY - 2018/8/25/pubmed
PY - 2019/7/10/medline
PY - 2018/8/25/entrez
KW - AIS
KW - AIS = adolescent idiopathic scoliosis
KW - C2–T1 Ha = C2–T1 Harrison measurement
KW - CBVA = chin-brow vertical angle
KW - CK = cervical kyphosis
KW - CL = cervical lordosis
KW - LL = lumbar lordosis
KW - MGS = McGregor slope
KW - PI = pelvic incidence
KW - PT = pelvic tilt
KW - SLS = slope of line of sight
KW - SS = sacral slope
KW - SVA = sagittal vertical axis
KW - TK = thoracic kyphosis
KW - adolescent idiopathic scoliosis
KW - cervical alignment
KW - cervical kyphosis
KW - cervical lordosis
KW - cervical spine
KW - deformity
KW - sagittal alignment
SP - 506
EP - 514
JF - Journal of neurosurgery. Spine
JO - J Neurosurg Spine
VL - 29
IS - 5
N2 - OBJECTIVEThe goal of this study was to investigate the impact of thoracic and lumbar alignment on cervical alignment in patients with adolescent idiopathic scoliosis (AIS).METHODSEighty-one patients with AIS who had a Cobb angle > 40° and full-length spine radiographs were included. Radiographs were analyzed using dedicated software to measure pelvic parameters (sacral slope [SS], pelvic incidence [PI], pelvic tilt [PT]); regional parameters (C1 slope, C0-C2 angle, chin-brow vertical angle [CBVA], slope of line of sight [SLS], McRae slope, McGregor slope [MGS], C2-7 [cervical lordosis; CL], C2-7 sagittal vertical axis [SVA], C2-T3, C2-T3 SVA, C2-T1 Harrison measurement [C2-T1 Ha], T1 slope, thoracic kyphosis [TK], lumbar lordosis [LL], and PI-LL mismatch); and global parameters (SVA). Patients were stratified by their lumbar alignment into hyperlordotic (LL > 59.7°) and normolordotic (LL 39.3° to 59.7°) groups and also, based on their thoracic alignment, into hypokyphotic (TK < -33.1°) and normokyphotic (TK -33.1° to -54.9°) groups. Finally, they were grouped based on their global alignment into either an anterior-aligned group or a posterior-aligned group.RESULTSThe lumbar hyperlordotic group, in comparison to the normolordotic group, had a significantly larger LL, SS, PI (all p < 0.001), and TK (p = 0.014) and a significantly smaller PI-LL mismatch (p = 0.001). Lumbar lordosis had no influence on local cervical parameters.The thoracic hypokyphotic group had a significantly larger PI-LL mismatch (p < 0.002) and smaller T1 slope (p < 0.001), and was significantly more posteriorly aligned than the normokyphotic group (-15.02 ± 8.04 vs 13.54 ± 6.17 [mean ± SEM], p = 0.006). The patients with hypokyphotic AIS had a kyphotic cervical spine (cervical kyphosis [CK]) (p < 0.001). Furthermore, a posterior-aligned cervical spine in terms of C2-7 SVA (p < 0.006) and C2-T3 SVA (p < 0.001) was observed in the thoracic hypokyphotic group.Comparing patients in terms of global alignment, the posterior-aligned group had a significantly smaller T1 slope (p < 0.001), without any difference in terms of pelvic, lumbar, and thoracic parameters when compared to the anterior-aligned group. The posterior-aligned group also had a CK (-9.20 ± 1.91 vs 5.21 ± 2.95 [mean ± SEM], p < 0.001) and a more posterior-aligned cervical spine, as measured by C2-7 SVA (p = 0.003) and C2-T3 SVA (p < 0.001).CONCLUSIONSAlignment of the cervical spine is closely related to thoracic curvature and global alignment. In patients with AIS, a hypokyphotic thoracic alignment or posterior global alignment was associated with a global cervical kyphosis. Interestingly, upper cervical and cranial parameters were not statistically different in all investigated groups, meaning that the upper cervical spine was not recruited for compensation in order to maintain a horizontal gaze.
SN - 1547-5646
UR - https://www.unboundmedicine.com/medline/citation/30141764/Sagittal_alignment_of_the_cervical_spine_in_the_setting_of_adolescent_idiopathic_scoliosis_
L2 - https://thejns.org/doi/10.3171/2018.3.SPINE171263
DB - PRIME
DP - Unbound Medicine
ER -