title: The Clinical Correlation of the Hart-ISSG Proximal Junctional Kyphosis Severity Scale With Health-Related Quality-of-life Outcomes and Need for Revision Surgery.
abstract: METHODS
  Retrospective analysis of prospective data.
  
  
  OBJECTIVE
  Evaluate the utility of the Hart-International Spine Study Group proximal junctional kyphosis severity scale (Hart-ISSG PJKSS).
  
  
  BACKGROUND
  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 χ² 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.
  
  
  CONCLUSIONS
  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.
  
  
  METHODS
  3.
authors.affiliation: *Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA†Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, MD,‡Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA§Department of Neurological Surgery, University of Virginia, Charlottesville, VA¶Rocky Mountain Scoliosis & Spine, Denver, CO||Department of Orthopaedic Surgery, New York University, New York, NY**Department of Orthopaedic Surgery, Oregon Health and Science University, Portland, OR.
authors.forename: Darryl
authors.initials: D
authors.lastname: Lau
authors.forename: Haruki
authors.initials: H
authors.lastname: Funao
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Clark
authors.forename: Fred
authors.initials: F
authors.lastname: Nicholls
authors.forename: Justin
authors.initials: J
authors.lastname: Smith
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.forename: Chris
authors.initials: C
authors.lastname: Shaffrey
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwab
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
authors.forename: Vedat
authors.initials: V
authors.lastname: Deviren
authors.forename: Robert
authors.initials: R
authors.lastname: Hart
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Kebaish
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D012086:Reoperation / Q000639:trends; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013904:Thoracic Vertebrae / Q000601:surgery; D016896:Treatment Outcome