[The importance of finger extension test in the diagnosis of occult wrist ganglion].

OBJECTIVES: The aim of this study was to evaluate the accuracy of diagnostic tools in comparison with surgical results of occult ganglion cyst of the wrist, which is one of the causes of chronic wrist pain.

METHODS: Twenty-five patients (4 males, 21 females; mean age 29 years; range 16 to 46 years) underwent surgery with an initial diagnosis of occult ganglion following unsuccessful conservative treatment. The mean symptom duration was 29 months (range 3 months to 10 years). Diagnosis was based on finger extension test performed in 24 patients. Six patients and 13 patients were assessed by ultrasonography and magnetic resonance imaging (MRI), respectively. Interosseous neurectomy was performed in three patients. The mean follow-up was 31 months (range 6 to 72 months).

RESULTS: Occult dorsal ganglion was resected from the scapholunate interval in 22 patients (88%). No ganglion was found in three patients, who had only degeneration of the scapholunate ligament. Finger extension test was positive in 23 patients. One patient with a negative test result was found to have degeneration of the scapholunate ligament. The test yielded two false positive results, one of which was negative by MRI. Surgical confirmation was achieved in 11 patients evaluated by MRI and in four patients evaluated by ultrasonography. Diagnostic accuracy rates for MRI, ultrasonography, and finger extension test were 92%, 66%, and 92%, respectively. Two patients (8%) underwent reoperation for recurrence. None of the patients complained of instability in the late period. Except for one patient, all patients (96%) were asymptomatic at final evaluations.

CONCLUSION: Finger extension test is an important diagnostic tool for occult ganglion with 92% accuracy. Both diagnosis and treatment of occult ganglion cysts have become easier by evolving diagnostic tools.