Thoracolumbar junction orientation: A novel guide for sagittal correction and proximal junctional kyphosis prediction in adult spinal deformity patients

Hong Joo Moon; Keith H. Bridwell; Alekos A. Theologis; Micheal P. Kelly; Thamrong Lertudomphonwanit; Lawrence G. Lenke; Munish C. Gupta

doi:10.1093/neuros/nyaa311

Thoracolumbar junction orientation: A novel guide for sagittal correction and proximal junctional kyphosis prediction in adult spinal deformity patients

Hong Joo Moon
, Keith H. Bridwell
, Alekos A. Theologis
, Micheal P. Kelly
, Thamrong Lertudomphonwanit
, Lawrence G. Lenke
, Munish C. Gupta

Department of Orthopedic

Korea University College of Medicine
Washington University in St. Louis
University of California San Francisco
Columbia University Medical Center

Research output: Contribution to journal › Article › peer-review

25 Citations (Scopus)

Abstract

BACKGROUND: Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis. OBJECTIVE: To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO. METHODS: A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameter_Pre6wk and preop-final follow/up = ΔParameter_PreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJA_PreFinal >15^◦). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters. RESULTS: Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater ΔTK_PreFinal, ΔLL_Pre6wk, and ΔTLS_Pre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of −9.4^◦ for ΔTLS_Pre6wk. PJK was significantly correlated with ΔTK_PreFinal and ΔTLS_Pre6wk. The linear correlation revealed that ΔTLS_Pre6wk < −25.3^◦ is the risk factor of PJK > 15^◦. CONCLUSION: As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

Original language	English
Pages (from-to)	55-62
Number of pages	8
Journal	Neurosurgery
Volume	88
Issue number	1
DOIs	https://doi.org/10.1093/neuros/nyaa311
Publication status	Published - 1 Jan 2021

Keywords

Lumbar degenerative kyphosis
Proximal junctional kyphosis
Reciprocal change
Sagittal alignment
Thoracolumbar slope
Thracolumbar junction orientation

Access to Document

10.1093/neuros/nyaa311

Cite this

@article{6d882b41a50e4332aae3a7283f160e93,

title = "Thoracolumbar junction orientation: A novel guide for sagittal correction and proximal junctional kyphosis prediction in adult spinal deformity patients",

abstract = "BACKGROUND: Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis. OBJECTIVE: To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO. METHODS: A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameterPre6wk and preop-final follow/up = ΔParameterPreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJAPreFinal >15◦). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters. RESULTS: Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater ΔTKPreFinal, ΔLLPre6wk, and ΔTLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of −9.4◦ for ΔTLSPre6wk. PJK was significantly correlated with ΔTKPreFinal and ΔTLSPre6wk. The linear correlation revealed that ΔTLSPre6wk < −25.3◦ is the risk factor of PJK > 15◦. CONCLUSION: As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.",

keywords = "Lumbar degenerative kyphosis, Proximal junctional kyphosis, Reciprocal change, Sagittal alignment, Thoracolumbar slope, Thracolumbar junction orientation",

author = "Moon, \{Hong Joo\} and Bridwell, \{Keith H.\} and Theologis, \{Alekos A.\} and Kelly, \{Micheal P.\} and Thamrong Lertudomphonwanit and Lenke, \{Lawrence G.\} and Gupta, \{Munish C.\}",

note = "Publisher Copyright: Copyright {\textcopyright} 2020 by the Congress of Neurological Surgeons",

year = "2021",

month = jan,

day = "1",

doi = "10.1093/neuros/nyaa311",

language = "English",

volume = "88",

pages = "55--62",

journal = "Neurosurgery",

issn = "0148-396X",

publisher = "Lippincott Williams and Wilkins",

number = "1",

}

TY - JOUR

T1 - Thoracolumbar junction orientation

T2 - A novel guide for sagittal correction and proximal junctional kyphosis prediction in adult spinal deformity patients

AU - Moon, Hong Joo

AU - Bridwell, Keith H.

AU - Theologis, Alekos A.

AU - Kelly, Micheal P.

AU - Lertudomphonwanit, Thamrong

AU - Lenke, Lawrence G.

AU - Gupta, Munish C.

PY - 2021/1/1

Y1 - 2021/1/1

N2 - BACKGROUND: Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis. OBJECTIVE: To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO. METHODS: A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameterPre6wk and preop-final follow/up = ΔParameterPreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJAPreFinal >15◦). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters. RESULTS: Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater ΔTKPreFinal, ΔLLPre6wk, and ΔTLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of −9.4◦ for ΔTLSPre6wk. PJK was significantly correlated with ΔTKPreFinal and ΔTLSPre6wk. The linear correlation revealed that ΔTLSPre6wk < −25.3◦ is the risk factor of PJK > 15◦. CONCLUSION: As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

AB - BACKGROUND: Novel radiographic sagittal parameters of the thoracolumbar junction orientation (TLJO, thoracolumbar slope [TLS] and thoracolumbar tilt [TLT]) have been introduced and correlated with lumbopelvic parameters and thoracic kyphosis. OBJECTIVE: To determine a predictive model for reciprocal thoracic kyphosis and proximal junctional kyphosis (PJK) based on the TLJO. METHODS: A total of 127 patients who had fusion from sacrum to T10-L2 from 2004 to 2014 were reviewed. TK (T5-T12), PI, SS, PT, LL, and proximal junctional angle (PJA) were measured preoperatively, 6 wk postoperatively, and at final follow-up. TLJO was measured by TLS and TLT. Changes between time points were determined (preop-6 wk = ΔParameterPre6wk and preop-final follow/up = ΔParameterPreFinal). Scoliosis Research Society (SRS) and Oswestry Disability Index (ODI) questionnaires were evaluated at final follow-up. Patients were divided into 2 groups based on the presence of PJK (ΔPJAPreFinal >15◦). Independent t-tests and receiver operating characteristic (ROC) curves were used to investigate the significance of differences and cut-off values. Pearson correlations and linear regressions were used to analyze the entire cohort to determine the relationship between the changes in parameters. RESULTS: Compared to patients without PJK (n = 100), those with PJK (n = 27) had significantly lower SRS scores and significantly greater ΔTKPreFinal, ΔLLPre6wk, and ΔTLSPre6wk. To maintain in the nonPJK group, ROC curves demonstrated a cut-off value of −9.4◦ for ΔTLSPre6wk. PJK was significantly correlated with ΔTKPreFinal and ΔTLSPre6wk. The linear correlation revealed that ΔTLSPre6wk < −25.3◦ is the risk factor of PJK > 15◦. CONCLUSION: As change of TLS reflects lumbopelvic realignment and influences reciprocal TK, reducing the change of TLS may be a sagittal realignment guideline to reduce the risk of PJK.

KW - Lumbar degenerative kyphosis

KW - Proximal junctional kyphosis

KW - Reciprocal change

KW - Sagittal alignment

KW - Thoracolumbar slope

KW - Thracolumbar junction orientation

UR - https://www.scopus.com/pages/publications/85098531717

U2 - 10.1093/neuros/nyaa311

DO - 10.1093/neuros/nyaa311

M3 - Article

C2 - 32761200

AN - SCOPUS:85098531717

SN - 0148-396X

VL - 88

SP - 55

EP - 62

JO - Neurosurgery

JF - Neurosurgery

IS - 1

ER -

Thoracolumbar junction orientation: A novel guide for sagittal correction and proximal junctional kyphosis prediction in adult spinal deformity patients

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this