Klippel–Feil Syndrome with Sprengel Deformity and Extensive Upper Extremity Deformity: A Case Report and Literature Review

Introduction. Klippel–Feil syndrome (KFS) is a congenital anomaly resulting from fusion of cervical vertebral bodies secondary to the dysregulation of signaling pathways during somite development. It is commonly associated with scoliosis and Sprengel deformity. We present a case of KFS with commonly associated abnormalities as well as deformities that have not yet been reported in the literature. Case Presentation. A 3-year-old girl presented for further evaluation of a left upper extremity deformity following a negative genetic workup. Upon physical exam and radiographic imaging, the patient was diagnosed with KFS and associated abnormalities including cervical scoliosis, Sprengel deformity, and congenital deformity of the left upper extremity. Deformities of the left upper extremity include radioulnar synostosis, a four-rayed hand, and absent thenar musculature. The Sprengel deformity was corrected surgically with a Woodward procedure. Discussion. Congenital musculoskeletal deformities can be differentiated based upon spinal and limb embryology. The presence of extraspinal abnormalities not originating from somite differentiation may suggest a severe form of KFS. Important considerations in the workup of the KFS patient include looking for deformities of the shoulder girdle and upper extremities to identify abnormalities for intervention at a young age