The clinical correlation of the hart-issg proximal junctional kyphosis severity scale with health-related quality-of-life outcomes and need for revision surgery

Darryl Lau, Haruki Funao, Aaron J. Clark, Fred Nicholls, Justin Smith, Shay Bess, Chris Shaffrey, Frank J. Schwab, Virginie Lafage, Vedat Deviren, Robert Hart, Khaled M. Kebaish, Christopher P. Ames

Research output: Contribution to journalArticlepeer-review

43 Scopus citations


Study Design. Retrospective analysis of prospective data. Objective. Evaluate the utility of the Hart-International Spine Study Group proximal junctional kyphosis severity scale (Hart-ISSG PJKSS). Summary of Background Data. Proximal junctional kyphosis (PJK) and failure (PJF) are well-described complications after long-segment instrumentation. The Hart-ISSG PJKSS was recently developed and incorporates neurological deficit, pain, instrumentation issues, degree of kyphosis, presence of fracture, and level of upper-most instrumented vertebrae. Methods. All adult spinal deformity patients with PJK or PJF were identified from two academic centers over a 7-year period. Health-related quality-of-life (HRQOL) outcomes were prospectively collected: Oswestry Disability Index (ODI), visual analogue scale (VAS) pain, SF-36 questionnaire, and SRS-30 questionnaire. Patients were retrospectively assigned Hart-ISSG PJKSS scores. Correlation between the Hart-ISSG PJKSS and outcomes was assessed with linear regression, Pearson correlation coefficients, and χ 2 analysis. Results. A total of 184 cases were included; 21.2% were men and mean age was 65.0 years. Weakness and/or myelopathy were present in 11.4% of patients and 88.6% had pain. Instrumentation issues occurred in 44.0% and 64.1% had PJK-associated fractures. PJK occurred in the upper thoracic spine in 21.7% of cases. Mean PJKSS score was 5.9. The Hart-ISSG PJKSS was significantly and strongly associated with ODI (P<0.001, r=0.611), VAS pain (P<0.001, r=0.676), SRS-30 function (P<0.001, r=-0.401), SRS-30 mental health (P<0.001, r=-0.592), SRS-30 self-image (P<0.001, r=-0.511), SRS-30 satisfaction (P<0.001, r=-0.531), and SRS-30 pain (P<0.001, r=-0.445). Higher scores were associated with higher proportion of patients undergoing revision surgery (P<0.001); scores of 9 to 11 and 12 to 15 underwent revision 96.0% and 100.0% of the time, respectively. Conclusion. The Hart-ISSG PJKSS was strongly correlated with validated functional outcomes and higher scores were associated with higher rates of revision surgery. The Hart-ISSG PJKSS may be a useful clinical tool in the treatment of patient with PJK.

Original languageEnglish (US)
Pages (from-to)213-223
Number of pages11
Issue number3
StatePublished - Feb 1 2016


  • classification
  • instrumentation
  • proximal junctional failure
  • proximal junctional kyphosis
  • quality of life
  • revision surgery
  • severity scale

ASJC Scopus subject areas

  • Clinical Neurology
  • Orthopedics and Sports Medicine


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