SYMPHONY™ OCT System for Instabilities of the Upper Thoracic and Cervical Spine

Radiographic Fusion at 24 months as inferred by Presence of Segmental Stability and Absence of Mechanical Failure on Xray/CT

The primary objective of this study is to evaluate the radiographic assessment of fusion at 24 months postoperatively. This radiographic assessment will consist of plain Xrays preoperatively, at 6 weeks, 3 months, 6 months and 24 months postoperatively. These will include a combination of anterior, lateral, flexion and extension views images of the spine used to infer stability. Fusion failure (pseudarthrosis) will be defined as signs of mechanical failure (such as peri-implant radiolucency/haloing, screw/rod fracture, etc.) or \<50% bridging trabecular bone on CT scan at 12 months postoperatively. Assessment of fusion will be conducted by a musculoskeletal radiologist and 2 independent fellowship trained spine surgeons.

Changes in Patient Reported Pain as Measured Using Visual Analogue Scale Score Throughout Follow up Period

At predetermined intervals (preoperative, at time of discharge and 6 weeks, 3 months, 6 months, 12 months and 24 months follow up), subjective patient pain will be recorded using the Visual Analogue Scale which ranges from 0 to 10 with a score of 10 indicating the most severe possible pain and a score of 0 indicating no pain is present. A secondary objective of this study is to prospectively gather patient reported outcomes (PROMs) in terms of pain and function

Changes in Patient Reported Function as Measured Using Short Form 12 Throughout Follow up Period

At predetermined intervals (preoperative, at time of discharge and 6 weeks, 3 months, 6 months, 12 months and 24 months follow up), subjective patient function will be recorded using the Short Form 12 which returns component scores representing both physical and mental status. These scores are adjusted and compare versus averages within the United States population. Both scores have an average score of 50 with a standard deviation of 10. Lower scores indicate worse function while higher scores indicate greater function.

Changes in Patient Reported Function as Measured Using Neck Disability Index Throughout Follow up Period

At predetermined intervals (preoperative, at time of discharge and 6 weeks, 3 months, 6 months, 12 months and 24 months follow up), subjective patient function will be recorded using the Neck Disability Index which ranges from 0 to 100 disability with a score of 100% indicating complete disability and a score of 0% indicating no disability is present.