A MODIFICATION OF THE BALLOTTEMENT TEST IN THE ASSESSMENT OF DISTAL RADIOULNAR JOINT INSTABILITY

Abstract

Background: An important sign in the assessment of distal radioulnar joint instability is the ballottement test were passive movement of the affected joint is compared to the contralateral normal side. The subjective appreciation of increased laxity renders the test positive.

In cases in which the contralateral side can not be tested or is known to be abnormal the relevance of the ballottement test is compromised.

Based on the observation that distal radioulnar joint passive mobility decreases in normal subjects when the wrist is radially deviated we propose a modification of the ballottement test in which mobility of the DRUJ is tested both in radial and ulnar wrist deviation.

Objectives: We aim to verify the observed decreased range of motion of the DRUJ in normal individuals when assessed in radial deviation compared to ulnar deviation and report the intraoperative findings of a series of patients who demonstrated an abnormal modified ballottement test in the abscense of bony deformity in the DRUJ.

Method: A group of 38 healthy volunteers (76 wrists) with no history of significant wrist injuries were assessed and the amount of DRUJ mobility given a subjective score of between 1 and 3. All wrists were assessed in ulnar and radial deviation as well as in neutral. The average age of the participants was 32.4 years. There were 22 female and 16 male subjects.

Our clinical case series reports the review of clinic notes and operative records of 32 patients (age gender) (32 wrists) who demonstrated an abnormal modified ballottement test and whose degree of instability granted surgical intervention.

Results: Out of the 76 normal wrists, 72 demonstrated decreased range of movement of the DRUJ in wrist radial deviation compared to examination in neutral or ulnar deviation. In the remaining 4 no difference was perceived but examination in neutral was considered “stiff” (less than average on the examiners experience).

All patients in the case series were found to have an ulnar detachment of the dorsal aspect of the TFCC (Palmer 1B) for which they underwent open repair.

Conclusion: DRUJ mobility in normal wrists decreases in radial deviation compared to neutral.

The observed decreased mobility of the DRUJ is likely to be due to tightening of the ulno-carpal ligaments.

An abnormal modified ballottement test was an indicator of severity as those with a positive result required surgical intervention and also correlated with the anatomical lesion found at surgery (Palmer 1B TFCC tear)

We believe the proposed modification enhances the diagnostic value of the DRUJ ballottement test and also allows to detect abnormalities in those cases in which the contralateral side can not be examined.