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.

Magnetic Resonance Imaging is increasingly utilised for the assessment of knee pathology. The aim of this study was to review our entire knee MRI scans and to assess the accuracy of diagnosis when compared with operative diagnosis. Using data from the radiology department and medical records (public and private) all patients having knee MRI scans in a 6-year period were identified.

There were 956 scans performed on 930 patients. Scan diagnosis, operative diagnosis and diagnostic accuracy were assessed. Of the scanned patients 181 (19.5%) had normal scans and of these 168 (92.8%) were accurately diagnosed as normal. The remaining 749 (80.5%) had an abnormality noted on scan and of these 298 (39.8%) proceeded on to surgery. Of those patients having surgery, diagnosis at surgery was found to exactly match the results of the scan in 163 (57.0%) patients. Furthermore 51.5% of patients with a diagnosis of meniscal degeneration by scan actually had a meniscal tear at operation. However the sensitivity for diagnosis of ACL tears was 89.0% and that of medial meniscal tears was 90.6%.

MRI diagnosis is far from infallible and clinicians should be conscious of its limitations. However it is particularly reliable in confirming the lack of pathology within a knee with an accuracy of 93%. It also has high sensitivity for diagnosis of ACL and meniscal tears.