Standard imaging of complex intra-articular distal radius fractures consists of posterior-anterior, lateral and oblique x-rays. Recently the liberal use of CT scan in this area became widely accepted as an additional imaging tool in pre-operative evaluation. The aim of this study was to evaluate whether CT scanning of complex distal radius fractures changed the management of these fractures compared to plain films. A series of 20 closed distal radius complex intra-articular fractures AO 12-C which had both plain PA, lateral and oblique films and CT scans were selected from our long bone trauma database. The plain films were blindly reviewed by five observers. A management plan was then formulated. Options provided were: closed manipulation, closed manipulation with percutaneous K wire fixation, open reduction and internal fixation, external fixature or bone graft/substitute. The same patients' CT scans (in randomised order) were blindly reviewed at the one week interval by the same clinicians with the same management options decided upon. Kappa statistic was used to measure the intra-individual agreement between x-ray and CT, as well as inter-individual agreement within each imagining modality. The agreement between individual observer's management decisions, based on the x-rays and on the CT scan was poor; with an average Kappa score of 0.038 (range 0.006 to 0.19). A regression model with management as a graded 5 level variable ranging from least invasive to most invasive and imaging modality as the predictor gave an estimated coefficient of 0.163, (p=-0.267); this indicates a trend towards a slightly higher level of invasiveness when the management decision was based on the CT compared to the plain x-rays. The agreement on management decisions between the observers based on x-ray alone was higher than that based on CT alone (kapa=0.174 vs 0.03) This study indicates a very poor level of agreement between decision-making, based on x-ray and on CT. Even within individual's ‘interindividual’ agreement appears higher with x-ray than CT. This study also raises the possibility that the use of CT scans increases the level of invasiveness in the surgical management of complex distal radius fractures.
