Determining diagnosis of scaphoid healing: Comparison of cone beam CT and X-ray after six weeks of immobilization

Highlights • Scaphoid union is controversial regarding diagnosis of healing. • XR is the most used modality with poor reliability and reproducibility. • CBCT allows with higher confidence diagnosis of consolidation avoiding longer immobilisation. • Evaluation for translation is better with CBCT than XR at un early follow up. • Six weeks is a reasonable delay to perform the first imaging follows up in waist scaphoid fracture.
Purpose To assess the accuracy and reliability of using cone beam computed tomography (CBCT) compared to X-ray six weeks after injury for predicting scaphoid union. Materials and methods Overall; 52 patients with scaphoid fractures between April 2018 and March 2019 were prospectively included in this study. The mean age was 34.52 (13–88) years, and the gender ratio male/female 43/9. Of the fractures, 26 had occurred on the right side, and 26 on the left side. In total, 28 % of patients were manual workers. All patients underwent X-ray and CBCT six weeks after injury. Four readers, two radiologists, and two hand surgeons analyzed the findings using double-blinded X-ray and CBCT and categorized fractures as consolidated based on a 50 % visibility threshold concerning trabecular bridges. Proximal pole sclerosis, communition, cyst formation, and humpback deformity were similarly analyzed for all cases. Agreement between readers was calculated using Kappa, and sensitivity, specificity, and accuracy using RStudio software. The gold standard was the radiologic and clinical follow-up for all patients at two months. Results Inter-reader agreement between the four readers was moderate concerning X-ray (0.543) but substantial concerning CBCT (0.641). It was almost perfect between seniors regarding CBCT (Kappa = 0.862). Sensitivity, specificity, and accuracy were 0.75–0.78, 0.4, and 0.61–0.64, respectively, for two readers regarding CBCT. The X-ray values were 0.65–0.71, 0.35–0.4, and 0.53–0.59, respectively. Conclusion CBCT proves more accurate and reliable than X-ray for diagnosing scaphoid union at an early follow-up and prevents longer immobilization and interruption of activity or work.