Postoperative imaging of orthopaedic hardware in the hand and wrist: is there an added value for tomosynthesis?

AIM: To prospectively investigate digital tomosynthesis (DTS) as an alternative to digital radiography (DR) for postoperative imaging of orthopaedic hardware after trauma or arthrodesis in the hand and wrist.

MATERIALS AND METHODS: Thirty-six consecutive patients (12 female, median age 36 years, range 19-86 years) were included in this institutional review board approved clinical trial. Imaging was performed with DTS in dorso-palmar projection and DR was performed in dorso-palmar, lateral, and oblique views. Images were evaluated by two independent radiologists for qualitative and diagnosis-related imaging parameters using a four-point Likert scale (1=excellent, 4not diagnostic) and nominal scale. Interobserver agreement between the two readers was assessed with Cohen's kappa (k). Differences between DTS and CR were tested with Wilcoxon's signed-rank test. A p-value <0.05 was considered statistically significant.

RESULTS: Regarding image quality, interobserver agreement was higher for DTS compared to DR, especially for fracture-related parameters (delineation osteosynthesis material [OSM]: KDTS 0.96 versus KDR 0.45; delineation fracture margins: KDTS 0.78 versus KDR 0.35). Delineation of fracture margins and delineation of adjacent joint spaces scored significant better for DTS compared to DR (delineation fracture margins: DTS1.54, DR2.28, p0.001; delineation adjacent joint spaces: DTS1.31, DR2.24, p0.001). Regarding diagnosis-related findings, interobserver agreement was almost equal. DTS showed a significant higher sharpness of fracture margins (DTS1.94, DR2.33, p0.04). Mean dose area product (DAP) for DTS was significant higher compared to DR (mean DR0.219 Gy·cm2 , mean DTS0.903 Gy·cm2 , p0.001).

CONCLUSION: Fracture healing is more visible and interobserver agreement is higher for DTS compared to DR in the postoperative assessment of orthopaedic hardware in the hand and wrist.