KLIPPEL-FEIL SYNDROME - PATTERNS OF BONY FUSION AND WASP-WAIST SIGN

Cervical spine radiographs of 33 patients with Klippel-Feil syndrome w ere studied for patterns of bony fusion and presence of wasp-waist sig n. Five patients were found to have the classic features of massive ce rvical fusion. Two patients with two adjacent levels of bony fusion sh owed a wasp-waist sign. Fusion at one level of the cervical spine acco unted for 26 remaining cases. The wasp-waist sign was observed in 14 o f the cases in which there was complete vertebral interbody fusion, ma king this finding a valuable radiologic sign. Partial anterior or post erior vertebral interbody fusion, or isolated fusion of the neural arc h, however, may or may not be associated with the wasp-waist sign. Kli ppel-Feil syndrome, easy to recognize when presenting with classic fea tures or when associated with the wasp-waist sign, may be confused wit h a variety of other entities.