Radiological grading of wrist osteoarthritis associated with scaphoid nonunion advanced collapse (SNAC) can be difficult. A comparison radiograph of the contralateral healthy wrist and an educational training in the various SNAC stages may improve reliability. Our purposes were to evaluate the difference in the reliability: (1) between observers who rate SNAC wrists with and without a comparison radiograph; and (2) between observers who receive training prior to ratings and those who do not.
In this cross-sectional survey study, 82 fully trained orthopedic or hand surgeons rated anteroposterior radiographs of 19 patient wrists following a scaphoid nonunion based on SNAC stages 0 to 4. Observers were randomized online in 4 groups: one group rated unilateral views without training, a second group unilateral views with training, a third group bilateral views without training, and a fourth group bilateral views with training. Training included a 1-page clarification of the SNAC stages. Interobserver agreement was calculated using kappa statistics.
There was no significant difference between agreement between observers who rated unilateral radiographs (κ = 0.55) and who rated bilateral radiographs (κ = 0.58) ( P = .14), nor between agreement between observers who received training (κ = 0.59) and who did not (κ = 0.54) ( P = .058).
The use of an additional comparison view and/or training does not seem to be clinically relevant in SNAC staging. There is room for improvement in the way we assess patients with SNAC wrists.