Proximal Junctional Kyphosis: Inter- and Intra-observer Reliability of Radiographic Measurements in Adult Spinal Deformity

Farbod Rastegar, Alec Contag, Alan Daniels, Jayme Hiratzka, Clifford Lin, Jason Chang, Khoi Than, Ahmed Raslan, Christopher Kong, Ngoc Lam Nguyen, Richard Hostin, Marie Kane, Robert Hart

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

STUDY DESIGN.: Reliability study of radiographic measures of proximal junctional kyphosis in adult spinal deformity patients. OBJECTIVE.: Assess impacts of level of proximal endpoint and vertebral fracture on reliability of measurement of junctional kyphosis. SUMMARY OF BACKGROUND DATA.: Radiographic assessment is important in determining management of patients with Proximal Junctional Kyphosis (PJK) or Proximal Junctional Failure (PJF). No study to date has evaluated the reliability of radiographic measurement of the junctional kyphotic angle after surgery for Adult Spinal Deformity (ASD). METHODS.: Post-operative radiographs from 52 ASD patients were divided into four categories based on the level of the upper instrumented vertebra (UIV) and the presence or absence of PJF: upper thoracic without failure (UT), thoracolumbar without failure (TL), upper thoracic with PJF (UTF) and thoracolumbar with PJF (TLF). Nine surgeon reviewers performed radiographic measurements of kyphosis between UIV+2 and UIV twice at least 4-weeks apart. Intraclass correlation coefficients (ICC) were calculated to determine inter- and intra-observer reliability. RESULTS.: Inter-observer reliability for measurements of UT, TL, UTF, TLF were all “almost perfect” with ICC scores of 0.917, 0.965, 0.956, 0.882, and 0.932, 0.975, 0958, 0.989, for sessions 1 and 2 respectively. Similarly, ICCʼs for kyphosis measurements for the TL and TLF group had “almost perfect” agreement with means of 0.898 (range: 0.817–0.969) and 0.976 (range: 0.931–0.995), respectively. ICCʼs for measurements for the UT and UTF groups all had “substantial” or “almost perfect” agreement with means of 0.801 (range: 0.662–0.942) and 0.879 (range: 0.760–0.988), respectively. CONCLUSION.: This study demonstrates high inter- and intra-observer reliability of proximal junctional kyphosis measurement following instrumented fusion for ASD, independent of the presence or absence of PJF. Although slightly lower for upper thoracic than for thoracolumbar proximal endpoints, all ICCʼs consistently reached at least “substantial agreement” and “near perfect agreement” for most.Level of Evidence: 4

Original languageEnglish (US)
JournalSpine
DOIs
StateAccepted/In press - Jun 6 2017

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Kyphosis
Spine
Thorax
Spinal Fusion

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Clinical Neurology

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Proximal Junctional Kyphosis : Inter- and Intra-observer Reliability of Radiographic Measurements in Adult Spinal Deformity. / Rastegar, Farbod; Contag, Alec; Daniels, Alan; Hiratzka, Jayme; Lin, Clifford; Chang, Jason; Than, Khoi; Raslan, Ahmed; Kong, Christopher; Nguyen, Ngoc Lam; Hostin, Richard; Kane, Marie; Hart, Robert.

In: Spine, 06.06.2017.

Research output: Contribution to journalArticle

Rastegar, Farbod ; Contag, Alec ; Daniels, Alan ; Hiratzka, Jayme ; Lin, Clifford ; Chang, Jason ; Than, Khoi ; Raslan, Ahmed ; Kong, Christopher ; Nguyen, Ngoc Lam ; Hostin, Richard ; Kane, Marie ; Hart, Robert. / Proximal Junctional Kyphosis : Inter- and Intra-observer Reliability of Radiographic Measurements in Adult Spinal Deformity. In: Spine. 2017.
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title = "Proximal Junctional Kyphosis: Inter- and Intra-observer Reliability of Radiographic Measurements in Adult Spinal Deformity",
abstract = "STUDY DESIGN.: Reliability study of radiographic measures of proximal junctional kyphosis in adult spinal deformity patients. OBJECTIVE.: Assess impacts of level of proximal endpoint and vertebral fracture on reliability of measurement of junctional kyphosis. SUMMARY OF BACKGROUND DATA.: Radiographic assessment is important in determining management of patients with Proximal Junctional Kyphosis (PJK) or Proximal Junctional Failure (PJF). No study to date has evaluated the reliability of radiographic measurement of the junctional kyphotic angle after surgery for Adult Spinal Deformity (ASD). METHODS.: Post-operative radiographs from 52 ASD patients were divided into four categories based on the level of the upper instrumented vertebra (UIV) and the presence or absence of PJF: upper thoracic without failure (UT), thoracolumbar without failure (TL), upper thoracic with PJF (UTF) and thoracolumbar with PJF (TLF). Nine surgeon reviewers performed radiographic measurements of kyphosis between UIV+2 and UIV twice at least 4-weeks apart. Intraclass correlation coefficients (ICC) were calculated to determine inter- and intra-observer reliability. RESULTS.: Inter-observer reliability for measurements of UT, TL, UTF, TLF were all “almost perfect” with ICC scores of 0.917, 0.965, 0.956, 0.882, and 0.932, 0.975, 0958, 0.989, for sessions 1 and 2 respectively. Similarly, ICCʼs for kyphosis measurements for the TL and TLF group had “almost perfect” agreement with means of 0.898 (range: 0.817–0.969) and 0.976 (range: 0.931–0.995), respectively. ICCʼs for measurements for the UT and UTF groups all had “substantial” or “almost perfect” agreement with means of 0.801 (range: 0.662–0.942) and 0.879 (range: 0.760–0.988), respectively. CONCLUSION.: This study demonstrates high inter- and intra-observer reliability of proximal junctional kyphosis measurement following instrumented fusion for ASD, independent of the presence or absence of PJF. Although slightly lower for upper thoracic than for thoracolumbar proximal endpoints, all ICCʼs consistently reached at least “substantial agreement” and “near perfect agreement” for most.Level of Evidence: 4",
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T2 - Inter- and Intra-observer Reliability of Radiographic Measurements in Adult Spinal Deformity

AU - Rastegar, Farbod

AU - Contag, Alec

AU - Daniels, Alan

AU - Hiratzka, Jayme

AU - Lin, Clifford

AU - Chang, Jason

AU - Than, Khoi

AU - Raslan, Ahmed

AU - Kong, Christopher

AU - Nguyen, Ngoc Lam

AU - Hostin, Richard

AU - Kane, Marie

AU - Hart, Robert

PY - 2017/6/6

Y1 - 2017/6/6

N2 - STUDY DESIGN.: Reliability study of radiographic measures of proximal junctional kyphosis in adult spinal deformity patients. OBJECTIVE.: Assess impacts of level of proximal endpoint and vertebral fracture on reliability of measurement of junctional kyphosis. SUMMARY OF BACKGROUND DATA.: Radiographic assessment is important in determining management of patients with Proximal Junctional Kyphosis (PJK) or Proximal Junctional Failure (PJF). No study to date has evaluated the reliability of radiographic measurement of the junctional kyphotic angle after surgery for Adult Spinal Deformity (ASD). METHODS.: Post-operative radiographs from 52 ASD patients were divided into four categories based on the level of the upper instrumented vertebra (UIV) and the presence or absence of PJF: upper thoracic without failure (UT), thoracolumbar without failure (TL), upper thoracic with PJF (UTF) and thoracolumbar with PJF (TLF). Nine surgeon reviewers performed radiographic measurements of kyphosis between UIV+2 and UIV twice at least 4-weeks apart. Intraclass correlation coefficients (ICC) were calculated to determine inter- and intra-observer reliability. RESULTS.: Inter-observer reliability for measurements of UT, TL, UTF, TLF were all “almost perfect” with ICC scores of 0.917, 0.965, 0.956, 0.882, and 0.932, 0.975, 0958, 0.989, for sessions 1 and 2 respectively. Similarly, ICCʼs for kyphosis measurements for the TL and TLF group had “almost perfect” agreement with means of 0.898 (range: 0.817–0.969) and 0.976 (range: 0.931–0.995), respectively. ICCʼs for measurements for the UT and UTF groups all had “substantial” or “almost perfect” agreement with means of 0.801 (range: 0.662–0.942) and 0.879 (range: 0.760–0.988), respectively. CONCLUSION.: This study demonstrates high inter- and intra-observer reliability of proximal junctional kyphosis measurement following instrumented fusion for ASD, independent of the presence or absence of PJF. Although slightly lower for upper thoracic than for thoracolumbar proximal endpoints, all ICCʼs consistently reached at least “substantial agreement” and “near perfect agreement” for most.Level of Evidence: 4

AB - STUDY DESIGN.: Reliability study of radiographic measures of proximal junctional kyphosis in adult spinal deformity patients. OBJECTIVE.: Assess impacts of level of proximal endpoint and vertebral fracture on reliability of measurement of junctional kyphosis. SUMMARY OF BACKGROUND DATA.: Radiographic assessment is important in determining management of patients with Proximal Junctional Kyphosis (PJK) or Proximal Junctional Failure (PJF). No study to date has evaluated the reliability of radiographic measurement of the junctional kyphotic angle after surgery for Adult Spinal Deformity (ASD). METHODS.: Post-operative radiographs from 52 ASD patients were divided into four categories based on the level of the upper instrumented vertebra (UIV) and the presence or absence of PJF: upper thoracic without failure (UT), thoracolumbar without failure (TL), upper thoracic with PJF (UTF) and thoracolumbar with PJF (TLF). Nine surgeon reviewers performed radiographic measurements of kyphosis between UIV+2 and UIV twice at least 4-weeks apart. Intraclass correlation coefficients (ICC) were calculated to determine inter- and intra-observer reliability. RESULTS.: Inter-observer reliability for measurements of UT, TL, UTF, TLF were all “almost perfect” with ICC scores of 0.917, 0.965, 0.956, 0.882, and 0.932, 0.975, 0958, 0.989, for sessions 1 and 2 respectively. Similarly, ICCʼs for kyphosis measurements for the TL and TLF group had “almost perfect” agreement with means of 0.898 (range: 0.817–0.969) and 0.976 (range: 0.931–0.995), respectively. ICCʼs for measurements for the UT and UTF groups all had “substantial” or “almost perfect” agreement with means of 0.801 (range: 0.662–0.942) and 0.879 (range: 0.760–0.988), respectively. CONCLUSION.: This study demonstrates high inter- and intra-observer reliability of proximal junctional kyphosis measurement following instrumented fusion for ASD, independent of the presence or absence of PJF. Although slightly lower for upper thoracic than for thoracolumbar proximal endpoints, all ICCʼs consistently reached at least “substantial agreement” and “near perfect agreement” for most.Level of Evidence: 4

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