Disparities in Etiology, Clinical Presentation and Determinants for Distal Junctional Kyphosis Based on Timing of Occurrence: Are We Treating Two Separate Issues?. (16th November 2020)

• Record Type: Journal Article
• Authors: Pierce, Katherine; Passias, Peter; Renaud, Lafage; Lafage, Virginie; Daniels, Alan H; Eastlack, Robert; Klineberg, Eric; Line, Breton G; Hart, Robert A; Burton, Douglas C; Bess, Shay; Schwab, Frank; Shaffrey, Christopher I; Smith, Justin S; Ames, Christopher P
• Is Part Of: Neurosurgery. Volume 67(2010)Supplement 1
• Publication Date: 2020-11-16
• Subjects: Nervous system -- Surgery -- Periodicals; 617.48005
• DOI: 10.1093/neuros/nyaa447_690
• Languages: English
• ISSNs: 0148-396X

Abstract

Abstract: INTRODUCTION: Following cervical deformity(CD) corrective surgery, durability remains a challenge and distal junctional kyphosis(DJK) is an important risk for a surgeon to consider. DJK is the result from fixation failure, adjacent level fracture or spondylolisthesis. The timing of DJK onset has yet to be investigated. METHODS: Included: surgical CD patients(C2-C7 Cobb>10°, CL>10°, cSVA>4cm, or CBVA>25°) without pre-op DJK. DJK angle was defined as the change in kyphosis between LIV)and LIV-2 from preop to postop(<−10). X 2 analysis and post-hoc testing assessed annual and overall incidence of Early(3M follow-u) and Late(after 3M) DJK development. Pearson correlations determined significant variables associated with development of Early versus Late DJK. Severe DJK was defined as DJK angle <−20°. DJK was considered symptomatic if associated with reoperation or the previously published thresholds of NDI>24 or mJOA<14. The natural progression of the disease was predicted with the use of a Kaplan-Meier survivorship analysis. RESULTS: 139 patients were included(16 re-op) (61.8yrs, 62.3%F, 29.1kg/m 2 ). Incidence of DJK from 2013–2018: 23%. Early: 9.4%, Late: 10.1%. No differences were observed between op and reop for development of Early or Late DJK at all f/u (p>0.050). Between Early and Late groups, 41.7% of Early DJK were severe, while 0% of Late ( P = .010); symptomatic DJK between the two groups was not significant (p = 0.941). Kaplan-Meier survivorship analysis determined patients have a 91.1% probability of maintaining non-DJK status by 3-month follow-up, 85.9% at 6-month, 80% at 1-year, and 77.0% by 2-year follow-up. CONCLUSION: Early DJK occurrence is more likely to be severe radiographically, associated with neurological decline, and is related to biomechanical factors such as combined approach. Contrarily, although equally likely to be symptomatic as reflected in loss of clinical gains, late DJK is more likely mild radiographically and associated with suboptimal cervical realignment and lack of addressing secondary drivers, likely related to negative compensatory mechanisms. Customized prophylactic approaches for both occurrences is mandated.