Inter-and intra-rater reliability of the hart-ISSG proximal junctional failure severity scale

Robert A. Hart, Farbod Rastegar, Alec Contag, Marie Kane, Alan Daniels, Eric Klineberg, Robert Eastlack, Justin S. Smith, Richard Hostin, D. Kojo Hamilton, Jeffrey L. Gum, Douglas C. Burton, Justin K. Sheer, Christopher Ames, Frank Schwab, Virginie Lafage, Shay Bess, Christopher Shaffrey, Khaled Kebaish

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Study Design. Reliability/external validation study. Objective. Investigate inter- and intrarater reliability of the Hart-International Spine Study Group (ISSG) Proximal Junctional Failure Severity Scale (PJFSS) and its correlation with operative revision in patients with proximal junctional failure (PJF). Summary of Background Data. The Hart-ISSG PJFSS is a validated classification system for PJF. Reliability of the PJFSS has not been assessed. Methods. Sixteen detailed clinical scenarios were assessed using the ISSG PJFSS classification in six categories: neurologic status, axial pain, instrumentation issue, proximal kyphotic angle, level of upper instrumented vertebrae (UIV), and severity of UIV/UIV+1 fracture. Eleven spine surgeons evaluated each case in all six categories during two different assessments, and provided recommendations regarding operative revision or observation for each case. Inter- and intrarater reliability were calculated based on intraclass correlation coefficients. Results. All intraclass correlation coefficients demonstrated "almost perfect"' (0.817-0.988) inter-rater agreement for both assessments, except UIV/UIV+1 fracture severity during the second assessment, which demonstrated "substantial" agreement' (0.692). Five of six categories had "almost perfect" mean intrarater reliability (0.805-0.981), while "instrumentation issue" demonstrated "substantial" mean agreement (0.757). Inter-rater reliability for recommendation of surgical intervention was "almost perfect" during both assessments (0.911 and 0.922, respectively). Mean PJFSS scores between the two assessments were significantly higher for cases recommended for operative revision (8.43±0.90) versus cases recommended for observation (P<0.0001). Conclusion. The ISSG PJFSS is a reliable and repeatable classification system for assessing patients with PJF. Higher PJFSS scales correlate with recommendation for operative revision, extending prior external validation of the PJFSS.

Original languageEnglish (US)
Pages (from-to)E461-E467
Issue number8
StatePublished - Apr 15 2018


  • Adult spinal deformity
  • Complications
  • Proximal junctional failure
  • Proximal junctional kyphosis
  • Validation

ASJC Scopus subject areas

  • Clinical Neurology
  • Orthopedics and Sports Medicine


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