Cervical alignment changes in patients developing proximal junctional kyphosis following surgical correction of adult spinal deformity

International Spine Study Group

Research output: Contribution to journalReview articlepeer-review

8 Scopus citations


BACKGROUND: Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery is a well-documented complication, but associations between radiographic PJK and cervical malalignment onset remain unexplored. OBJECTIVE: To study cervical malalignment in ASD surgical patients that develop PJK. METHODS: Retrospective review of prospective multicenter database. Inclusion: primary ASD patients (≥5 levels fused, upper instrumented vertebra [UIV] at T2 or above, and 1-yr minimum follow-up) without baseline cervical deformity (CD), defined as ≥2 of the following criteria: T1 slope minus cervical lordosis < 20, cervical sagittal vertical axis < 4 cm, C2-C7 cervical lordosis < 10. PJK presence (<10 change in UIV and UIV + 2 kyphosis) and angle were identified 1 yr postoperative. Propensity score matching between PJK and nonPJK groups controlled for baseline alignment. Preoperative and 1-yr postoperative cervical alignment were compared between PJK and nonPJK patients. RESULTS: One hundred sixty-three patients without baseline CD (54.9 yr, 83.9% female) were included. PJK developed in 60 (36.8%) patients, with 27 (45%) having UIV above T7. PJK patients had significantly greater baseline T1 slope in unmatched and propensity score matching comparisons (P < .05). At 1 yr postoperative, PJK patients had significantly higher T1 slope (P < .001), C2-T3 Cobb (P = .04), and C2-T3 sagittal vertical axis (P = .02). New-onset CD rate in PJK patients was 15%, and 16.5% in nonPJK patients (P > .05). Increased PJK magnitude was associated with increasing T1 slope and C2-T3 SVA (P < .05). CONCLUSION: Patients who develop PJK following surgical correction of ASD have a 15% incidence of development of new-onset CD. Patients developing PJK following surgical correction of ASD tend to have an increased preoperative T1 slope. Increased progression of C2-T3 Cobb angle and C2-T3 SVA are associated with development of PJK following surgical correction of thoracolumbar deformity.

Original languageEnglish (US)
Pages (from-to)675-682
Number of pages8
JournalClinical Neurosurgery
Issue number4
StatePublished - Oct 1 2018


  • Adult spinal deformity
  • Cervical sagittal alignment
  • Cervicothoracic alignment
  • New-onset cervical deformity
  • Postoperative alignment
  • Proximal junctional kyphosis
  • Thoracolumbar deformity

ASJC Scopus subject areas

  • Medicine(all)


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