PT  - JOURNAL ARTICLE
AU  - HORN, SAMANTHA R.
AU  - BORTZ, COLE A.
AU  - RAMACHANDRAN, SUBARAMAN
AU  - POORMAN, GREGORY W.
AU  - SEGRETO, FRANK
AU  - SIOW, MATT
AU  - SURE, AKHILA
AU  - VASQUEZ-MONTES, DENNIS
AU  - DIEBO, BASSEL
AU  - TISHELMAN, JARED
AU  - MOON, JOHN
AU  - ZHOU, PETER
AU  - BEAUBRUN, BRYAN
AU  - VIRA, SHALEEN
AU  - JALAI, CYRUS
AU  - WANG, CHARLES
AU  - SHENOY, KARTIK
AU  - BEHERY, OMAR
AU  - ERRICO, THOMAS
AU  - LAFAGE, VIRGINIE
AU  - BUCKLAND, AARON
AU  - PASSIAS, PETER G.
TI  - Suboptimal Age-Adjusted Lumbo-Pelvic Mismatch Predicts Negative Cervical-Thoracic Compensation in Obese Patients
AID  - 10.14444/6034
DP  - 2019 Jun 01
TA  - International Journal of Spine Surgery
PG  - 252--261
VI  - 13
IP  - 3
4099  - https://www.ijssurgery.com/content/13/3/252.short
4100  - https://www.ijssurgery.com/content/13/3/252.full
SO  - Int J Spine Surg2019 Jun 01; 13
AB  - Background: Given the paucity of literature regarding compensatory mechanisms used by obese patients with sagittal malalignment, it is necessary to gain a better understanding of the effects of obesity on compensation after comparing the degree of malalignment to age-adjusted ideals. This study aims to compare baseline alignment of obese and nonobese patients using age-adjusted spino-pelvic alignment parameters, describing associated spinal changes.Methods: Patients ≥ 18 years with full-body stereoradiographs were propensity-score matched for sex, baseline pelvic incidence (PI), and categorized as nonobese (body mass index < 30kg/m2) or obese (body mass index ≥ 30). Age-adjusted ideals were calculated for sagittal vertical axis, spino-pelvic mismatch (PI-LL), pelvic tilt, and T1 pelvic angle using established formulas. Patients were stratified as meeting alignment ideals, being above ideal, or being below. Spinal alignment parameters included C0-C2, C2-C7, C2-T3, cervical thoracic pelvic angle, cervical sagittal vertical axis SVA, thoracic kyphosis, T1 pelvic angle, T1 slope, sagittal vertical axis, lumbar lordosis (LL), PI, PI-LL, pelvic tilt. Lower-extremity parameters included sacrofemoral angle, knee flexion (KA), ankle flexion (AA), pelvic shift (PS), and global sagittal angle (GSA). Independent t tests compared parameters between cohorts.Results: Included: 800 obese, 800 nonobese patients. Both groups recruited lower-extremity compensation: sacrofemoral angle (P = .004), KA, AA, PS, GSA (all P < .001). Obese patients meeting age-adjusted PI-LL had greater lower-extremity compensation than nonobese patients: lower sacrofemoral angle (P = .002), higher KA (P = .008), PS (P = .002), and GSA (P = .02). Obese patients with PI-LL mismatch higher than age-adjusted ideal recruited greater lower-extremity compensation than nonobese patients: higher KA, AA, PS, GSA (all P < .001). Obese patients showed compensation through the cervical spine: increased C0-C2, C2-C7, C2-T3, and cervical sagittal vertical axis (all P < .001), high T1 pelvic angle (P < .001), cervical thoracic pelvic angle (P = .03), and T1 slope (P < .001), with increased thoracic kyphosis (P = .015) and decreased LL (P < .001) compared to nonobese patients with PI-LL larger than age-adjusted ideal.Conclusions: Regardless of malalignment severity, obese patients recruited lower-limb compensation more than nonobese patients. Obese patients with PI-LL mismatch larger than age-adjusted ideal also develop upper-cervical and cervicothoracic compensation for malalignment.Level of Evidence: IIIClinical Relevance: Clinical evaluation should extend to the cervical spine in obese patients not meeting age-adjusted sagittal alignment ideals.