Prospective assessment of cervical fusion status: plain radiographs versus CT-scan

The purpose of this prospective study was to compare the pseudarthrosis rate after anterior cervical fusion, estimated either with static and dynamic plain radiographs or with two-dimensional CT-scans. There is a plethora of radiographic tools and criteria used to determine pseudarthrosis after cervical spine fusion. However, it is not known to which extent these tools correlate with each other. Forty-seven adult patients were enrolled in this study, about one year after surgery. Four independent blinded observers evaluated the roentgenological data. CT assessment led to higher pseudarthrosis rates than plain radiographs: 13 to 31% according to CT; 2 to 16% according to plain radiographs. The difference averaged 11%. Consistency between reviewers was higher with CT (average agreement: 89%; range 82%-96%) than with plain radiographs (average agreement: 81%; range: 76% to 87%). The need to accurately document pseudarthrosis is critical as it helps direct the postoperative management of the patient. The present study stresses the value of computed tomography. However, surgical exploration continues to be the gold standard.