A Rare Cause of Carpal Tunnel Syndrome: Volar Lunate Dislocation

Scientific BACKGROUND: Carpal tunnel syndrome (CTS) is a common neuropathy caused by entrapment of the median nerve at the wrist. Although most cases are idiopathic, CTS may be rarely associated with space occupying lesions. Volar lunate dislocation is a rare cause of CTS and may be easily misdiagnosed especially in patients with multiple traumas or when inadequate radiographs are obtained.
CASE: A 29-year-old right handed man was complaining of numbness in thumb, index and middle fingers of the right hand for two months. He was diagnosed with CTS by clinically and electrophysiologicaly on the right hand. Enlarged median nerve caused by compression of dislocated lunate bone was demonstrated by radiological findings.
CONCLUSION: Possible structural lesions may exist in patients with atypical clinical features of CTS, and radiological imaging modalities would be needed for diagnosis.