General Session: Value and Outcomes in Spine Surgery - Hall F

Presented by: N. Stekas

Author(s):

P. Passias(1), G. Poorman(1), S. Horn(1), B. Diebo(2), F. Segreto(1), C. Bortz(1), L. Steinmetz(1), D. Ge(1), E. Klineberg(3), C. Shaffrey(4), V. Lafage(5), T. Protopsaltis(1), C. Ames(6), J. Smith(7), G. Mundis(8), B. Neuman(9), R. Hart((1)0), D. Burton((1)(1)), International Spine Study Group

(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) University of California, Davis, CA, United States
(4) University of Virginia, Department of Orthopaedic Surgery, Charlottesville, VA, United States
(5) Hospital for Special Surgery, Department of Orthopedics, New York, NY, United States
(6) University of California, Department of Neurological Surgery, San Francisco, CA, United States
(7) University of Virginia, Department of Neurosurgery, Charlottesville, VA, United States
(8) San Diego Center for Spinal Disorders, La Jolla, CA, United States
(9) Johns Hopkins University, Department of Orthopaedics, Baltimore, MD, United States
(10) Swedish Neuroscience Institute, Department of Orthopaedic Surgery, Seattle, WA, United States
(11) University of Kansas Medical Center, Department of Orthopaedic Surgery, Kansas City, KS, United States

Abstract

Introduction: Cervical deformity (CD) patients are frequently older with numerous comorbidities and an uncertain ability to heal, making it difficult to justify total scoliosis correction. Neck pain, radiculopathy, and deformity are the primary complaints of CD patients. Identifying factors most likely to improve symptomology is key to patient selection and improving surgical outcomes. The aim of this study was to identify key prognostic variables associated with improvements in neck pain after cervical deformity surgery.

Methods: Retrospective review of a prospective multicenter database. Patients over 18 meeting one of the following CD criteria: cervical kyphosis (C2-7 Cobb angle >10°), cervical scoliosis (coronal Cobb angle >10°), positive cervical sagittal imbalance (C2-C7 sagittal vertical axis >4cm or T1-C6 >10°), or horizontal gaze impairment (chin-brow vertical angle >25°). Patients who reached 1 year postoperative MCID (defined as improvement >2.6 in NRS Neck and >1.2 in NRS Back) for pain improvement were compared to those who did not. Two groups, those who met MCID (MCID group), and those who did not (NOT group), were constructed with equal baseline Numeric Rating Scale (NRS) for neck pain by propensity score matching for baseline pain. Clinical and deformity data were analyzed using t-tests to identify how treatments that improved neck pain and back pain differed from those that did not.

Results: 122 patients (61.1 years, 60.4% female, 30.1 average BMI) presented with an average baseline neck pain score of 7.0. Patients improved neck pain at each follow-up time-point: 3months (4.4), 6 months (4.0), and 1-year (4.4), all p< 0.05. 51.1% of patients reached 1-year MCID improvement for neck pain. 33 MCID group patients were compared with 33 NOT group patients after matching for similar baseline NRS neck pain (neck MCID group: 7.0 vs. NOT: 6.8, p=0.72). NOT group patients had significantly more posterior approach surgeries (MCID: 37.5% vs. NOT: 62.5%, p=0.04) and were more frequently revisions (MCID: 25.8% revision vs. NOT: 53.1%, p=0.03), but had similar levels fused (MCID: 7.2 levels fused vs. NOT: 8.1 levels, p=0.32). Either group had similar cervical deformities, as measured by TS-CL, C2-C7 lordosis, and cervical SVA, all p>0.05. However, MCID group patients presented with large lumbar deformities: Pelvic Tilt (MCID: 22.3 vs. NOT: 16.6, p< 0.05) and PI-LL (MCID: 5.4 vs. NOT: -4.5, p=0.02). In evaluating secondary back pain change in cervical deformity corrections, patients presented with an average baseline back pain score of 5.2. Patients improved at each follow-up time-point: 3 months (4.6), 6 months (4.6), and 1-Year (4.8), all p< 0.05. 30.6% of patients met back pain MCID at 1-year. There was no significant overlap between patients who improved in back pain with those who improved in neck pain (MCID: 9.4% vs. NOT: 21.9%, p=0.30).

Conclusions: Revision status and posterior approach were found to be predictors of failure to reach significant improvement in neck pain. Patients also improved in lower back pain following cervical realignment, despite having primary cervical pathology.