T1 slope minus cervical lordosis (TS-CL), the cervical answer to PI-LL, defines cervical sagittal deformity in patients undergoing thoracolumbar osteotomy

International Spine Study Group

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Background: Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. Methods: A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing threecolumn osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 178. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL, 178); the two were compared using an unpaired t test. Logistic regression modeling was used to determine predictors of postoperative CSD. Results: A total of 223 patients with thoracolumbar deformity (mean age, 57.56 years) were identified. CTPA correlated with CPL (preoperative r = .85, postoperative r = .69). TS-CL correlated with CTPA (preoperative r = .52, postoperative r = .37) and CPL (preoperative r = .52; postoperative r = .37). CSD had greater preoperative CPL (P < .001) and CTPA (P < .001). The compensated cohort had a decrease in TS-CL (from 10.2 to 8.0) with sagittal vertical axis (SVA) correction, whereas the uncompensated had an increase in TS-CL (from 22.3 to 26.8) with all P, .001. Reciprocal change was demonstrated in the compensated group given that CL decreased with SVA correction (r=.39), but there was no such correlation in the uncompensated. Positive predictors of postoperative CSD included baseline TSCL > 17° (P = .007), longer fusion (P = .033), and baseline CTPA (P = .029). Conclusions: TS-CL and CTPA correlated significantly with established sagittal balance measures. Whereas reciprocal change in cervical and thoracolumbar alignment was demonstrated in the compensated cohort, the uncompensated population had progression of their cervical deformities after three-column osteotomy. Clinical Relevance: The balance between TS-CL mirrors the relationship between pelvic incidence minus lumbar lordosis in defining deformities of their respective spinal regions.

Original languageEnglish (US)
Pages (from-to)362-370
Number of pages9
JournalInternational Journal of Spine Surgery
Volume12
Issue number3
DOIs
StatePublished - Jun 1 2018

Fingerprint

Lordosis
Osteotomy
Thorax
Kyphosis
Linear Models
Logistic Models

Keywords

  • Alignment
  • Cervical kyphosis
  • CPL
  • Thoracolumbar deformity
  • TS-CL

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

Cite this

T1 slope minus cervical lordosis (TS-CL), the cervical answer to PI-LL, defines cervical sagittal deformity in patients undergoing thoracolumbar osteotomy. / International Spine Study Group.

In: International Journal of Spine Surgery, Vol. 12, No. 3, 01.06.2018, p. 362-370.

Research output: Contribution to journalArticle

@article{85d47806063d4b2eb66f66c5cec026b6,
title = "T1 slope minus cervical lordosis (TS-CL), the cervical answer to PI-LL, defines cervical sagittal deformity in patients undergoing thoracolumbar osteotomy",
abstract = "Background: Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. Methods: A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing threecolumn osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 178. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL, 178); the two were compared using an unpaired t test. Logistic regression modeling was used to determine predictors of postoperative CSD. Results: A total of 223 patients with thoracolumbar deformity (mean age, 57.56 years) were identified. CTPA correlated with CPL (preoperative r = .85, postoperative r = .69). TS-CL correlated with CTPA (preoperative r = .52, postoperative r = .37) and CPL (preoperative r = .52; postoperative r = .37). CSD had greater preoperative CPL (P < .001) and CTPA (P < .001). The compensated cohort had a decrease in TS-CL (from 10.2 to 8.0) with sagittal vertical axis (SVA) correction, whereas the uncompensated had an increase in TS-CL (from 22.3 to 26.8) with all P, .001. Reciprocal change was demonstrated in the compensated group given that CL decreased with SVA correction (r=.39), but there was no such correlation in the uncompensated. Positive predictors of postoperative CSD included baseline TSCL > 17° (P = .007), longer fusion (P = .033), and baseline CTPA (P = .029). Conclusions: TS-CL and CTPA correlated significantly with established sagittal balance measures. Whereas reciprocal change in cervical and thoracolumbar alignment was demonstrated in the compensated cohort, the uncompensated population had progression of their cervical deformities after three-column osteotomy. Clinical Relevance: The balance between TS-CL mirrors the relationship between pelvic incidence minus lumbar lordosis in defining deformities of their respective spinal regions.",
keywords = "Alignment, Cervical kyphosis, CPL, Thoracolumbar deformity, TS-CL",
author = "{International Spine Study Group} and Themistocles Protopsaltis and Jamie Terran and Alex Soroceanu and Moses, {Michael J.} and Nicolas Bronsard and Justin Smith and Eric Klineberg and Gregory Mundis and Kim, {Han Jo} and Richard Hostin and Robert Hart and Christopher Shaffrey and Shay Bess and Christopher Ames and Frank Schwab and Virginie Lafage",
year = "2018",
month = "6",
day = "1",
doi = "10.14444/5042",
language = "English (US)",
volume = "12",
pages = "362--370",
journal = "International Journal of Spine Surgery",
issn = "2211-4599",
publisher = "Elsevier USA",
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TY - JOUR

T1 - T1 slope minus cervical lordosis (TS-CL), the cervical answer to PI-LL, defines cervical sagittal deformity in patients undergoing thoracolumbar osteotomy

AU - International Spine Study Group

AU - Protopsaltis, Themistocles

AU - Terran, Jamie

AU - Soroceanu, Alex

AU - Moses, Michael J.

AU - Bronsard, Nicolas

AU - Smith, Justin

AU - Klineberg, Eric

AU - Mundis, Gregory

AU - Kim, Han Jo

AU - Hostin, Richard

AU - Hart, Robert

AU - Shaffrey, Christopher

AU - Bess, Shay

AU - Ames, Christopher

AU - Schwab, Frank

AU - Lafage, Virginie

PY - 2018/6/1

Y1 - 2018/6/1

N2 - Background: Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. Methods: A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing threecolumn osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 178. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL, 178); the two were compared using an unpaired t test. Logistic regression modeling was used to determine predictors of postoperative CSD. Results: A total of 223 patients with thoracolumbar deformity (mean age, 57.56 years) were identified. CTPA correlated with CPL (preoperative r = .85, postoperative r = .69). TS-CL correlated with CTPA (preoperative r = .52, postoperative r = .37) and CPL (preoperative r = .52; postoperative r = .37). CSD had greater preoperative CPL (P < .001) and CTPA (P < .001). The compensated cohort had a decrease in TS-CL (from 10.2 to 8.0) with sagittal vertical axis (SVA) correction, whereas the uncompensated had an increase in TS-CL (from 22.3 to 26.8) with all P, .001. Reciprocal change was demonstrated in the compensated group given that CL decreased with SVA correction (r=.39), but there was no such correlation in the uncompensated. Positive predictors of postoperative CSD included baseline TSCL > 17° (P = .007), longer fusion (P = .033), and baseline CTPA (P = .029). Conclusions: TS-CL and CTPA correlated significantly with established sagittal balance measures. Whereas reciprocal change in cervical and thoracolumbar alignment was demonstrated in the compensated cohort, the uncompensated population had progression of their cervical deformities after three-column osteotomy. Clinical Relevance: The balance between TS-CL mirrors the relationship between pelvic incidence minus lumbar lordosis in defining deformities of their respective spinal regions.

AB - Background: Cervical kyphosis and C2-C7 plumb line (CPL) are established descriptors of cervical sagittal deformity (CSD). Reciprocal changes in these parameters have been demonstrated in thoracolumbar deformity correction. The purpose of this study was to investigate the development of CSD, using T1 slope minus cervical lordosis (TS-CL) to define CSD and to correlate TS-CL and a novel global sagittal parameter, cervical-thoracic pelvic angle (CTPA), with CPL. Methods: A multicenter, retrospective analysis of patients with thoracolumbar deformity undergoing threecolumn osteotomy was performed. Preoperative and postoperative cervical parameters were investigated. Linear regression for postoperative values resulted in a CPL of 4 cm corresponding to a TS-CL threshold of 178. Patients were classified based on postoperative TS-CL into uncompensated (TS-CL > 17°) or compensated cohorts (TS-CL, 178); the two were compared using an unpaired t test. Logistic regression modeling was used to determine predictors of postoperative CSD. Results: A total of 223 patients with thoracolumbar deformity (mean age, 57.56 years) were identified. CTPA correlated with CPL (preoperative r = .85, postoperative r = .69). TS-CL correlated with CTPA (preoperative r = .52, postoperative r = .37) and CPL (preoperative r = .52; postoperative r = .37). CSD had greater preoperative CPL (P < .001) and CTPA (P < .001). The compensated cohort had a decrease in TS-CL (from 10.2 to 8.0) with sagittal vertical axis (SVA) correction, whereas the uncompensated had an increase in TS-CL (from 22.3 to 26.8) with all P, .001. Reciprocal change was demonstrated in the compensated group given that CL decreased with SVA correction (r=.39), but there was no such correlation in the uncompensated. Positive predictors of postoperative CSD included baseline TSCL > 17° (P = .007), longer fusion (P = .033), and baseline CTPA (P = .029). Conclusions: TS-CL and CTPA correlated significantly with established sagittal balance measures. Whereas reciprocal change in cervical and thoracolumbar alignment was demonstrated in the compensated cohort, the uncompensated population had progression of their cervical deformities after three-column osteotomy. Clinical Relevance: The balance between TS-CL mirrors the relationship between pelvic incidence minus lumbar lordosis in defining deformities of their respective spinal regions.

KW - Alignment

KW - Cervical kyphosis

KW - CPL

KW - Thoracolumbar deformity

KW - TS-CL

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U2 - 10.14444/5042

DO - 10.14444/5042

M3 - Article

AN - SCOPUS:85052146158

VL - 12

SP - 362

EP - 370

JO - International Journal of Spine Surgery

JF - International Journal of Spine Surgery

SN - 2211-4599

IS - 3

ER -