Predictive model for achieving good clinical and radiographic outcomes at one-year following surgical correction of adult cervical deformity
Peter Gust Passias1, Samantha R Horn1, Cheongeun Oh1, Gregory W Poorman1, Cole Bortz1, Frank Segreto1, Renaud Lafage2, Bassel Diebo3, Justin K Scheer4, Justin S Smith5, Christopher I Shaffrey6, Robert Eastlack7, Daniel M Sciubba8, Themistocles Protopsaltis1, Han Jo Kim2, Robert A Hart9, Virginie Lafage2, Christopher P Ames4, International Spine Study Group1
1 Department of Orthopaedic and Neurologic Surgery, NYU Langone Medical Center, New York Spine Institute, New York, USA
2 Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, USA
3 Department of Orthopaedic Surgery, SUNY Downstate Medical Center, Brooklyn, NY, USA
4 Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
5 Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA, USA
6 Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA
7 Department of Orthopaedic Surgery, Scripps Clinic, La Jolla, CA, USA
8 Department of Neurosurgery, Johns Hopkins Medical Center, Baltimore, MD, USA
9 Department of Orthopaedic Surgery, Swedish Medical Center, Seattle, WA, USA
Peter Gust Passias
Departments of Orthopaedic and Neurologic Surgery, New York Spine Institute, NYU Langone Medical Center – NYU Langone Orthopedic Hospital, 301 East 17th Street, New York, NY, 10003
Source of Support: None, Conflict of Interest: None
Background: For cervical deformity (CD) surgery, goals include realignment, improved patient quality of life, and improved clinical outcomes. There is limited research identifying patients most likely to achieve all three.
Objective: The objective is to create a model predicting good 1-year postoperative realignment, quality of life, and clinical outcomes following CD surgery using baseline demographic, clinical, and radiographic factors.
Methods: Retrospective review of a multicenter CD database. CD patients were defined as having one of the following radiographic criteria: Cervical sagittal vertical axis (cSVA) >4 cm, cervical kyphosis/scoliosis >10°° or chin-brow vertical angle >25°. The outcome assessed was whether a patient achieved both a good radiographic and clinical outcome. The primary analysis was stepwise regression models which generated a dataset-specific prediction model for achieving a good radiographic and clinical outcome. Model internal validation was achieved by bootstrapping and calculating the area under the curve (AUC) of the final model with 95% confidence intervals.
Results: Seventy-three CD patients were included (61.8 years, 58.9% F). The final model predicting the achievement of a good overall outcome (radiographic and clinical) yielded an AUC of 73.5% and included the following baseline demographic, clinical, and radiographic factors: mild-moderate myelopathy (Modified Japanese Orthopedic Association >12), no pedicle subtraction osteotomy, no prior cervical spine surgery, posterior lowest instrumented vertebra (LIV) at T1 or above, thoracic kyphosis >33°°, T1 slope <16 and cSVA <20 mm.
Conclusions: Achievement of a positive outcome in radiographic and clinical outcomes following surgical correction of CD can be predicted with high accuracy using a combination of demographic, clinical, radiographic, and surgical factors, with the top factors being baseline cSVA <20 mm, no prior cervical surgery, and posterior LIV at T1 or above.