Background: Pseudoarthrosis, a potential complication of cervical fusion, necessitates accurate diagnostic methods. This study evaluates the efficacy of dynamic radiographs in detecting pseudoarthrosis after Anterior Cervical Discectomy and Fusion (ACDF) using self-locking stand-alone intervertebral cages for treating Cervical Degenerative Disease (CDD). Methods: Retrospective analysis of radiological data from 47 patients (84 levels) who underwent 1- to 3-level ACDF with a minimum 24-month follow-up was conducted. Pseudoarthrosis was diagnosed via Computed Tomography (CT) by a blinded neuroradiologist. Two independent neurosurgeons measured Cobb angles in dynamic radiographs, correlating them with CT for pseudoarthrosis detection. The Intraclass Correlation Coefficient (ICC) assessed dynamic radiograph evaluator agreement, while ROC curves compared Cobb angle accuracy. Results: Excellent evaluator agreement was found in dynamic radiograph Cobb angle measurements (ICC = 0.993). Comparing Cobb angles between CT-diagnosed levels with and without pseudoarthrosis revealed a median of 6.3° for levels without fusion. A Cobb angle ≥ 5° exhibited higher specificity (85.9%), positive predictive value (47.4%) and accuracy (AUC = 0.762) than smaller angles (1°, 2°, 3° and 4°). Conclusion: In patients with Cervical Degenerative Disease (CDD) undergoing Anterior Cervical Discectomy and Fusion (ACDF) with self-locking stand-alone intervertebral cages, a Cobb angle change of ≥5° on dynamic radiographs appears to be a reliable threshold for predicting pseudoarthrosis. These findings support using this simple, non-invasive and cost-effective method as a valuable adjunct in diagnosing suspected pseudarthrosis, contributing to improved clinical decision-making in postoperative cervical fusion management.
Franz Jooji Onishi (Thu,) studied this question.