The carpal stretch test.

OBJECTIVE

To compare the sensitivity of traditional motion studies, bone scintigraphy and radiocarpal arthrography to a "carpal stretch test," for evaluation of dynamic dissociative carpal instability.

DESIGN

Experimental study comparing the results of the tests to the findings of arthroscopy, the "gold standard."

SETTING

A university hospital-based upper extremity practice.

PATIENTS

Six patients with chronic wrist pain, arthroscopically confirmed proximal row ligamentous disruption and radiographs not suggestive of proximal row instability.

INTERVENTIONS

The carpal stretch test: both affected and unaffected wrists were subjected to the same testing, wherein the wrist was suspended from finger traps for 10 minutes by a 4.5-kg weight. Standardized posteroanterior radiographs were taken of the suspended wrists.

MAIN OUTCOME MEASURES

Disruption of Gilula's arcs I and II, and sensitivity of the carpal stretch test compared with other investigations.

MAIN RESULTS

Step deformities ranging from 2.5 to 6 mm (average 3.7 mm) were recorded in the affected wrists and 0 to 4 mm (average 1.5 mm) in the "unaffected" wrists. The test was more sensitive than traditional radiography, arthrography and scintigraphy in defining both presence and site of proximal carpal row ligamentous tears and was almost as sensitive as arthroscopy.

CONCLUSION

In patients with chronic wrist pain and dynamic dissociative wrist instability, the carpal stretch test may prove to be a valuable screening tool for detecting ligamentous tears of the proximal carpal row.