Hand X-ray examination in two planes is not required for radiographic assessment of hand osteoarthritis.

Aims: Radiographic imaging is essential in the diagnosis of hand osteoarthritis (HOA); however, it is unknown whether a multiplanar examination would add essential information to dorso-palmar (dp) views alone. This study evaluated whether an additional radiographic view would aid clinicians in the diagnostic process of HOA.

Methods: The dp radiographs of both hands from 159 HOA patients were assessed according to the scores described by Kellgren and Lawrence (K/L). In oblique view images, structures similar to classic ostophytes (OPs) were found, namely bony proliferations on the dorsal and/or ventral margins of joints, and were documented as dorsal/ventral OPs (dvOPs). Function and pain were assessed by applying standardised read-out systems. Logistic regression analysis and Mann-Whitney tests were implemented.

Results: The presence of dvOPs was associated with the degree of joint damage; however, dp views were sufficient to estimate radiographic changes. Only a few joints showed dvOPs as the only structural alteration; nevertheless, in almost all cases, classical radiographic OA changes were found in dp views of other joints of the same or the contralateral hand. The presence of dvOPs did not affect joint function or pain according to established scores, but was associated with radiographic progression in distal interphalangeal joints.

Conclusion: This is the first study to confirm that additional radiographic planes, oblique/lateral views, are not necessary in the diagnostic process in HOA in daily clinical practice. Nevertheless, the presence of dvOPs reflect more severe joint damage and is associated with radiographic progression in HOA; hence, oblique/lateral views could be a useful tool for academic purposes.