Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA

Themistocles Protopsaltis, Nicolas Bronsard, Alex Soroceanu, Jensen K. Henry, Renaud Lafage, Justin Smith, Eric Otto Klineberg, Gregory Mundis, Han Jo Kim, Richard Hostin, Robert Hart, Christopher Shaffrey, Shay Bess, Christopher Ames, Spine Study Group International Spine Study Group

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Purpose: To describe reciprocal changes in cervical alignment after adult spinal deformity (ASD) correction and subsequent development of proximal junctional kyphosis (PJK). This study also investigated these changes using two novel global sagittal angular parameters, cervical–thoracic pelvic angle (CTPA) and the T1 pelvic angle (TPA). Methods: Multicenter, retrospective consecutive case series of ASD patients undergoing thoracolumbar three-column osteotomy (3CO) with fusion to the pelvis. Radiographs were analyzed at baseline and 1 year post-operatively. Patients were substratified into upper thoracic (UT; UIV T6 and above) and lower thoracic (LT; UIV below T6). PJK was defined by >10° angle between UIV and UIV + 2 and >10° change in the angle from baseline to post-op. Results: PJK developed in 29 % (78 of 267) of patients. CTPA was linearly correlated with cervical plumbline (CPL) as a measure of cervical sagittal alignment (R = 0.826, p < 0.001). PJK patients had significantly greater post-operative CTPA and SVA than patients without PJK (NPJK) (p = 0.042; p = 0.021). For UT (n = 141) but not LT (n = 136), PJK patients at 1 year had larger CTPA (4.9° vs. 3.7°, p = 0.015) and CPL (5.1 vs. 3.8 cm, p = 0.022) than NPJK patients, despite similar corrections in PT and PI-LL. Conclusions: The prevalence of PJK was 29 % at 1 year follow-up. CTPA, which correlates with CPL as a global analog of cervical sagittal balance, and TPA describe relative proportions of cervical and thoracolumbar deformities. Patients who develop PJK in the upper thoracic spine after thoracolumbar 3CO also develop concomitant cervical sagittal deformity, with increases in CPL and CTPA.

Original languageEnglish (US)
Pages (from-to)1-10
Number of pages10
JournalEuropean Spine Journal
DOIs
StateAccepted/In press - Jul 20 2016

Keywords

  • Adult spinal deformity
  • Cervical alignment
  • Proximal junctional kyphosis
  • Sagittal alignment
  • Three-column osteotomy

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

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    Protopsaltis, T., Bronsard, N., Soroceanu, A., Henry, J. K., Lafage, R., Smith, J., Klineberg, E. O., Mundis, G., Kim, H. J., Hostin, R., Hart, R., Shaffrey, C., Bess, S., Ames, C., & International Spine Study Group, S. S. G. (Accepted/In press). Cervical sagittal deformity develops after PJK in adult thoracolumbar deformity correction: radiographic analysis utilizing a novel global sagittal angular parameter, the CTPA. European Spine Journal, 1-10. https://doi.org/10.1007/s00586-016-4653-7