Effect of age-adjusted alignment goals and distal inclination angle on the fate of distal junctional kyphosis in cervical deformity surgery.
J Craniovertebr Junction Spine
washington; seattle; swedish neuro
Background: Age-adjusted alignment targets in the context of distal junctional kyphosis (DJK) development have yet to be investigated. Our aim was to assess age-adjusted alignment targets, reciprocal changes, and role of lowest instrumented level orientation in DJK development in cervical deformity (CD) patients.
Methods: CD patients were evaluated based on lowest fused level: cervical (C7 or above), upper thoracic (UT: T1-T6), and lower thoracic (LT: T7-T12). Age-adjusted alignment targets were calculated using published formulas for sagittal vertical axis (SVA), pelvic incidence-lumbar lordosis (PI-LL), pelvic tilt (PT), T1 pelvic angle (TPA), and LL-thoracic kyphosis (TK). Outcome measures were cervical and global alignment parameters: Cervical SVA (cSVA), cervical lordosis, C2 slope, C2-T3 angle, C2-T3 SVA, TS-CL, PI-LL, PT, and SVA. Subanalysis matched baseline PI to assess age-adjusted alignment between DJK and non-DJK.
Results: Seventy-six CD patients included. By 1Y, 20 patients developed DJK. Non-DJK patients had 27% cervical lowest instrumented vertebra (LIV), 68% UT, and 5% LT. DJK patients had 25% cervical, 50% UT, and 25% LT. There were no baseline or 1Y differences for PI, PI-LL, SVA, TPA, or PT for actual and age-adjusted targets. DJK patients had worse baseline cSVA and more severe 1Y cSVA, C2-T3 SVA, and C2 slope (
Conclusion: CD patients with severe baseline malalignment went on to develop postoperative DJK. Age-adjusted alignment targets did not capture differences in these populations, suggesting the need for cervical-specific goals.
Orthopedics & Sports Medicine
Neurosciences (Brain & Spine)
Passias, Peter Gust; Horn, Samantha R; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Line, Breton G; Protopsaltis, Themistocles S; Soroceanu, Alex; Bortz, Cole; Segreto, Frank A; Ahmad, Waleed; Naessig, Sara; Pierce, Katherine E; Brown, Avery E; Alas, Haddy; Kim, Han Jo; Daniels, Alan H; Klineberg, Eric O; Burton, Douglas C; Hart, Robert A; Schwab, Frank J; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; and Spine Study Group, International, "Effect of age-adjusted alignment goals and distal inclination angle on the fate of distal junctional kyphosis in cervical deformity surgery." (2021). Articles, Abstracts, and Reports. 4759.