Unique Sonographic Presentation of Distal Intersection Syndrome

Abstract

Distal intersection syndrome is the tenosynovitis of the second compartment and the third compartment, at their cross point, in the dorsal wrist. It is a rare disorder presenting with pain, swelling, and tenderness in Lister’s tubercle area of the wrist. One of the causes may be the pulley effect of Lister’s tubercle on the third compartment, where the resultant tenosynovitis can spread to the second compartment through their communication foramen. This case of distal intersection syndrome is induced by hyperflexion and abduction injury of the thumb, which may have caused tenosynovitis of the third compartment by overstretching over Lister’s tubercle. It is unique that in addition to the typical presentation of the syndrome with tenosynovitis of the second and third compartments, the fourth compartment also displayed tenosynovitis. This extra presentation may result from the possible communication between the third and fourth compartments.