Lightning Podiums: Smorgasboard - Room 802B

Presented by: P. Passias

Author(s):

P. Passias(1), G. Poorman(1), C. Wang(1), S. Vira(1), C. Jalai(1), B. Diebo(2), S. Horn(1), C. Bortz(1), F. Segreto(1), L. Steinmetz(1), C. Varlotta(1), J. Tishelman(1), S. Wang(3), R. Lafage(4), V. Lafage(4)

(1) New York University Langone Orthopedic Hospital, Division of Spinal Surgery, New York, NY, United States
(2) SUNY Downstate Medical Center, Department of Orthopedics, Brooklyn, NY, United States
(3) Peking University Third Hospital, Beijing, China
(4) Hospital for Special Surgery, Department of Orthopedics, New York, NY, United States

Abstract

Introduction: For patients with cervical deformity, simple decompression of stenosis may not be sufficient to relieve spinal cord compression and restore neurologic function. No comparison exists between deformity and nondeformity patients in amount of spinal canal volume change after realignment or decompression, respectively. The aim of this study was to compare the effects of decompression versus realignment on spinal canal dimension and functional outcomes in cervical spondylotic myelopathy (CSM) patients.

Methods: Prospective consecutive series. 31 patients with a primary diagnosis of CSM treated with either realignment or decompression procedures and with a minimum follow-up of 1 year were divided into 2 cohorts based on the presence of cervical deformity: cervical deformity (CD) and non-cervical deformity (non-D). Cervical deformity was defined as one or more of the following: cervical kyphosis (>10°), cervical scoliosis (>10°), cervical SVA >4cm, or horizontal gaze impairment (chin-brow vertical angle >25°). Preoperative and 1-year MRIs were assessed for spinal canal volume using imaging software and stenotic vertebral levels using Pavlov's method from C2-T1. Primary analysis evaluated changes in spinal cord volume, number of stenotic levels, and myelopathy score (mJOA) from baseline to 1-year between CD and non-D cohorts using t-tests.

Results: 14 patients with CD(age 60.2 years, BMI: 32.1, 54% female) were compared to 17 non-D patients (age 51.2 years, BMI: 27.7, 56% female). CD patients were corrected with constructs averaging 8.0 levels fused, were not decompressed (4/14), and a vertebral-body osteotomy (8/14). Non-D patients were corrected with constructs averaging 3.5 levels fused with decompression (17/17), and no vertebral-body osteotomies (0/17). Baseline canal volume was similar across deformity groups: (CD: 259.3 mm2 vs. non-D: 279.1 mm2, p=0.267). Change in volume to 1-year was similarly non-different (CD: +75.5 mm2 vs. non-D: +46.9 mm2, p=0.149). CD patients presented with comparable number of stenotic levels (CD: 4.7 vs. non-D: 4.2, p=0.484) and change in stenotic levels after surgery (CD: -2.0 vs. non-D: -1.8, p=0.807). Lastly, mJOA improvement was similar (CD: +0.50 vs. non-D: +1.8, p=0.449).

Conclusions: Among CD patients, realignment contributes to improvements in spinal canal and functional outcomes more significantly than direct decompression, with little additive impact of direct decompression. These findings are in stark contrast to the critical role of direct decompression among CSM patients without primary CD.