Paraspinal muscle size as an independent risk factor for proximal junctional kyphosis in patients undergoing thoracolumbar fusion

Zach Pennington, Ethan Cottrill, A. Karim Ahmed, Peter Passias, Themistocles Protopsaltis, Brian J Neuman, Khaled M Kebaish, Jeff Ehresman, Erick M. Westbroek, Matthew L. Goodwin, Daniel Sciubba

Research output: Contribution to journalArticle

Abstract

Objective: Proximal junctional kyphosis (PJK) is a structural complication of spinal fusion in 5%.61% of patients treated for adult spinal deformity. In nearly one-third of these cases, PJK is progressive and requires costly surgical revision. Previous studies have suggested that patient body habitus may predict risk for PJK. Here, the authors sought to investigate abdominal girth and paraspinal muscle size as risk factors for PJK. Methods: All patients undergoing thoracolumbosacral fusion greater than 2 levels at a single institution over a 5-year period with ≥ 6 months of radiographic follow-up were considered for inclusion. PJK was defined as kyphosis ≥ 20° between the upper instrumented vertebra (UIV) and two supra-adjacent vertebrae. Operative and radiographic parameters were recorded, including pre- and postoperative sagittal vertical axis (SVA), sacral slope (SS), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), and absolute value of the pelvic incidence.lumbar lordosis mismatch (|PI-LL|), as well as changes in LL, |PI-LL|, and SVA. The authors also considered relative abdominal girth and the size of the paraspinal muscles at the UIV. Results: One hundred sixty-nine patients met inclusion criteria. On univariate analysis, PJK was associated with a larger preoperative SVA (p < 0.001) and |PI-LL| (p = 0.01), and smaller SS (p = 0.004) and LL (p = 0.001). PJK was also associated with more positive postoperative SVA (p = 0.01), ΔSVA (p = 0.01), Δ|PI-LL| (p < 0.001), and ΔLL (p < 0.001); longer construct length (p = 0.005); larger abdominal girth.to-muscle ratio (p = 0.007); and smaller paraspinal muscles at the UIV (p < 0.001). Higher postoperative SVA (OR 1.1 per cm), smaller paraspinal muscles at the UIV (OR 2.11), and more aggressive reduction in |PI-LL| (OR 1.03) were independent predictors of radiographic PJK on multivariate logistic regression. Conclusions: A more positive postoperative global sagittal alignment and smaller paraspinal musculature at the UIV most strongly predicted PJK following thoracolumbosacral fusion.

Original languageEnglish (US)
Pages (from-to)380-388
Number of pages9
JournalJournal of Neurosurgery: Spine
Volume31
Issue number3
DOIs
StatePublished - Jan 1 2019

Fingerprint

Paraspinal Muscles
Lordosis
Kyphosis
Spine
Incidence
Abdominal Muscles
Spinal Fusion
Reoperation
Logistic Models

Keywords

  • Adjacent-segment disease
  • Adult spinal deformity
  • Body morphometry
  • Obesity
  • Proximal junctional kyphosis
  • Sagittal balance

ASJC Scopus subject areas

  • Surgery
  • Neurology
  • Clinical Neurology

Cite this

Paraspinal muscle size as an independent risk factor for proximal junctional kyphosis in patients undergoing thoracolumbar fusion. / Pennington, Zach; Cottrill, Ethan; Ahmed, A. Karim; Passias, Peter; Protopsaltis, Themistocles; Neuman, Brian J; Kebaish, Khaled M; Ehresman, Jeff; Westbroek, Erick M.; Goodwin, Matthew L.; Sciubba, Daniel.

In: Journal of Neurosurgery: Spine, Vol. 31, No. 3, 01.01.2019, p. 380-388.

Research output: Contribution to journalArticle

Pennington, Zach ; Cottrill, Ethan ; Ahmed, A. Karim ; Passias, Peter ; Protopsaltis, Themistocles ; Neuman, Brian J ; Kebaish, Khaled M ; Ehresman, Jeff ; Westbroek, Erick M. ; Goodwin, Matthew L. ; Sciubba, Daniel. / Paraspinal muscle size as an independent risk factor for proximal junctional kyphosis in patients undergoing thoracolumbar fusion. In: Journal of Neurosurgery: Spine. 2019 ; Vol. 31, No. 3. pp. 380-388.
@article{aee523af86f0438f98a7d1316a292fbb,
title = "Paraspinal muscle size as an independent risk factor for proximal junctional kyphosis in patients undergoing thoracolumbar fusion",
abstract = "Objective: Proximal junctional kyphosis (PJK) is a structural complication of spinal fusion in 5{\%}.61{\%} of patients treated for adult spinal deformity. In nearly one-third of these cases, PJK is progressive and requires costly surgical revision. Previous studies have suggested that patient body habitus may predict risk for PJK. Here, the authors sought to investigate abdominal girth and paraspinal muscle size as risk factors for PJK. Methods: All patients undergoing thoracolumbosacral fusion greater than 2 levels at a single institution over a 5-year period with ≥ 6 months of radiographic follow-up were considered for inclusion. PJK was defined as kyphosis ≥ 20° between the upper instrumented vertebra (UIV) and two supra-adjacent vertebrae. Operative and radiographic parameters were recorded, including pre- and postoperative sagittal vertical axis (SVA), sacral slope (SS), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), and absolute value of the pelvic incidence.lumbar lordosis mismatch (|PI-LL|), as well as changes in LL, |PI-LL|, and SVA. The authors also considered relative abdominal girth and the size of the paraspinal muscles at the UIV. Results: One hundred sixty-nine patients met inclusion criteria. On univariate analysis, PJK was associated with a larger preoperative SVA (p < 0.001) and |PI-LL| (p = 0.01), and smaller SS (p = 0.004) and LL (p = 0.001). PJK was also associated with more positive postoperative SVA (p = 0.01), ΔSVA (p = 0.01), Δ|PI-LL| (p < 0.001), and ΔLL (p < 0.001); longer construct length (p = 0.005); larger abdominal girth.to-muscle ratio (p = 0.007); and smaller paraspinal muscles at the UIV (p < 0.001). Higher postoperative SVA (OR 1.1 per cm), smaller paraspinal muscles at the UIV (OR 2.11), and more aggressive reduction in |PI-LL| (OR 1.03) were independent predictors of radiographic PJK on multivariate logistic regression. Conclusions: A more positive postoperative global sagittal alignment and smaller paraspinal musculature at the UIV most strongly predicted PJK following thoracolumbosacral fusion.",
keywords = "Adjacent-segment disease, Adult spinal deformity, Body morphometry, Obesity, Proximal junctional kyphosis, Sagittal balance",
author = "Zach Pennington and Ethan Cottrill and Ahmed, {A. Karim} and Peter Passias and Themistocles Protopsaltis and Neuman, {Brian J} and Kebaish, {Khaled M} and Jeff Ehresman and Westbroek, {Erick M.} and Goodwin, {Matthew L.} and Daniel Sciubba",
year = "2019",
month = "1",
day = "1",
doi = "10.3171/2019.3.SPINE19108",
language = "English (US)",
volume = "31",
pages = "380--388",
journal = "Journal of Neurosurgery: Spine",
issn = "1547-5654",
publisher = "American Association of Neurological Surgeons",
number = "3",

}

TY - JOUR

T1 - Paraspinal muscle size as an independent risk factor for proximal junctional kyphosis in patients undergoing thoracolumbar fusion

AU - Pennington, Zach

AU - Cottrill, Ethan

AU - Ahmed, A. Karim

AU - Passias, Peter

AU - Protopsaltis, Themistocles

AU - Neuman, Brian J

AU - Kebaish, Khaled M

AU - Ehresman, Jeff

AU - Westbroek, Erick M.

AU - Goodwin, Matthew L.

AU - Sciubba, Daniel

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Objective: Proximal junctional kyphosis (PJK) is a structural complication of spinal fusion in 5%.61% of patients treated for adult spinal deformity. In nearly one-third of these cases, PJK is progressive and requires costly surgical revision. Previous studies have suggested that patient body habitus may predict risk for PJK. Here, the authors sought to investigate abdominal girth and paraspinal muscle size as risk factors for PJK. Methods: All patients undergoing thoracolumbosacral fusion greater than 2 levels at a single institution over a 5-year period with ≥ 6 months of radiographic follow-up were considered for inclusion. PJK was defined as kyphosis ≥ 20° between the upper instrumented vertebra (UIV) and two supra-adjacent vertebrae. Operative and radiographic parameters were recorded, including pre- and postoperative sagittal vertical axis (SVA), sacral slope (SS), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), and absolute value of the pelvic incidence.lumbar lordosis mismatch (|PI-LL|), as well as changes in LL, |PI-LL|, and SVA. The authors also considered relative abdominal girth and the size of the paraspinal muscles at the UIV. Results: One hundred sixty-nine patients met inclusion criteria. On univariate analysis, PJK was associated with a larger preoperative SVA (p < 0.001) and |PI-LL| (p = 0.01), and smaller SS (p = 0.004) and LL (p = 0.001). PJK was also associated with more positive postoperative SVA (p = 0.01), ΔSVA (p = 0.01), Δ|PI-LL| (p < 0.001), and ΔLL (p < 0.001); longer construct length (p = 0.005); larger abdominal girth.to-muscle ratio (p = 0.007); and smaller paraspinal muscles at the UIV (p < 0.001). Higher postoperative SVA (OR 1.1 per cm), smaller paraspinal muscles at the UIV (OR 2.11), and more aggressive reduction in |PI-LL| (OR 1.03) were independent predictors of radiographic PJK on multivariate logistic regression. Conclusions: A more positive postoperative global sagittal alignment and smaller paraspinal musculature at the UIV most strongly predicted PJK following thoracolumbosacral fusion.

AB - Objective: Proximal junctional kyphosis (PJK) is a structural complication of spinal fusion in 5%.61% of patients treated for adult spinal deformity. In nearly one-third of these cases, PJK is progressive and requires costly surgical revision. Previous studies have suggested that patient body habitus may predict risk for PJK. Here, the authors sought to investigate abdominal girth and paraspinal muscle size as risk factors for PJK. Methods: All patients undergoing thoracolumbosacral fusion greater than 2 levels at a single institution over a 5-year period with ≥ 6 months of radiographic follow-up were considered for inclusion. PJK was defined as kyphosis ≥ 20° between the upper instrumented vertebra (UIV) and two supra-adjacent vertebrae. Operative and radiographic parameters were recorded, including pre- and postoperative sagittal vertical axis (SVA), sacral slope (SS), lumbar lordosis (LL), pelvic tilt, pelvic incidence (PI), and absolute value of the pelvic incidence.lumbar lordosis mismatch (|PI-LL|), as well as changes in LL, |PI-LL|, and SVA. The authors also considered relative abdominal girth and the size of the paraspinal muscles at the UIV. Results: One hundred sixty-nine patients met inclusion criteria. On univariate analysis, PJK was associated with a larger preoperative SVA (p < 0.001) and |PI-LL| (p = 0.01), and smaller SS (p = 0.004) and LL (p = 0.001). PJK was also associated with more positive postoperative SVA (p = 0.01), ΔSVA (p = 0.01), Δ|PI-LL| (p < 0.001), and ΔLL (p < 0.001); longer construct length (p = 0.005); larger abdominal girth.to-muscle ratio (p = 0.007); and smaller paraspinal muscles at the UIV (p < 0.001). Higher postoperative SVA (OR 1.1 per cm), smaller paraspinal muscles at the UIV (OR 2.11), and more aggressive reduction in |PI-LL| (OR 1.03) were independent predictors of radiographic PJK on multivariate logistic regression. Conclusions: A more positive postoperative global sagittal alignment and smaller paraspinal musculature at the UIV most strongly predicted PJK following thoracolumbosacral fusion.

KW - Adjacent-segment disease

KW - Adult spinal deformity

KW - Body morphometry

KW - Obesity

KW - Proximal junctional kyphosis

KW - Sagittal balance

UR - http://www.scopus.com/inward/record.url?scp=85072011640&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85072011640&partnerID=8YFLogxK

U2 - 10.3171/2019.3.SPINE19108

DO - 10.3171/2019.3.SPINE19108

M3 - Article

VL - 31

SP - 380

EP - 388

JO - Journal of Neurosurgery: Spine

JF - Journal of Neurosurgery: Spine

SN - 1547-5654

IS - 3

ER -