Seema M. Meraj MD, Presenter: Nothing to Disclose

Nidhi Jain MD, Abstract Co-Author: Nothing to Disclose

Catherine Niyada Petchprapa MD, Abstract Co-Author: Nothing to Disclose

Evaluate the dorsovolar position of the distal radius and ulna at the distal radioulnar joint (DRUJ) in forearm pronation, supination, and neutral in asymptomatic volunteers on MRI.

Twenty wrists in ten asymptomatic volunteers (five men, five women; mean age 29.6 years; range 27-32 years), without history of pain, prior trauma or previous hand/wrist surgery were imaged utilizing axial proton density weighted MRI with the wrist pronated, supinated, and in the neutral position. Three methods were used to quantify the presence/absence/degree of subluxation of the DRUJ: Mino criteria, subluxation ratio, and radioulnar ratio.

None of the volunteers had clinical DRUJ instability. Using the Mino criteria, DRUJ instability was suspected in 55% (11/20) of the wrists in pronation, 45% (9/20) in neutral, and 45% (9/20) in supination. Using the subluxation ratio method, only 2 of the wrists fit the criteria for subluxation in pronation and 1 in supination. Only 1 wrist fit the criteria for subluxation using the radioulnar ratio method in supination. The ulna was dorsally positioned in 7/20 with respect to the radius in pronation and volarly positioned in 5/20 in supination. The mean values for the radioulnar ratio method were 0.530 in pronation and 0.481 in supination. 

Established methods for evaluating DRUJ alignment were abnormal in our study of asymptomatic subjects, raising concern for their reliability for detecting true DRUJ instability.  

There is some degree of normal dorsovolar translation between the radius and ulna in pronation and supination. Further study of normal wrists is necessary to avoid overdiagnosing DRUJ instability on cross sectional imaging. 

Meraj, S, Jain, N, Petchprapa, C, Dorsovolar Position of the Distal Radius and Ulna at the Distal Radioulnar Joint in Asymptomatic Volunteers on MRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045690.html