Syndrome characterized by the congenital fusion of any two of the seven cervical vertebrae resulting in shortness of the neck, restricted neck movements, and low posterior hairline. Other features include congenital heart defect (eg, ventricular septal defect) and hearing loss.
Although this syndrome was first described in 1743 by the Swiss physician Albrecht von Haller (1708-1777), it now bears the name of the two French neurologists, Maurice Klippel (1858-1942) and André Feil (1884-?), who redescribed the disorder in 1912. In 1919, in his PhD thesis, André Feil suggested another classification of the syndrome encompassing not only deformation of the cervical spine, but also deformation of the lumbar and thoracic spine.
Estimated at approximately 1:42,000 live births. Females account for approximately 65%.
Autosomal dominant and autosomal recessive inheritance do occur, but most cases are sporadic. Gene map locus is 8q22.2.
Vertebral malformation caused by failure of normal segmentation of cervical somites during the third and eighth week of gestation with resulting associated primary or secondary neurologic defects. Four types are described:
Type I: Extensive cervical and upper thoracic spinal fusion
Type II: One to two interspace fusions often associated with occipitoatlantal fusion and hemivertebrae
Type III: Coexisting fusion in the lower thoracic or lumbar spine
Type IV: Klippel-Feil anomaly associated with sacral agenesis
Type I is 50 times less common than Type II, but tends to present with the classic triad (see Clinical aspects) and is frequently associated with birth injuries and other major organ abnormalities. Practically, the presence of spine anomalies in the form of hypermobility or spondylosis places these patients at higher risk for spinal cord injury with minor trauma.
Clinical suspicion is confirmed by radiography. Lateral flexion-extension radiographs of the cervical spine should be performed to determine the motion range at each interspace. Once diagnosed, patients should be followed with radiographic assessment at least annually.
The classic triad consists of short neck, restriction of neck movement, and low posterior hairline. Of these, restriction of movement is most common and occurs in up to 50% of cases. The syndrome often remains unrecognized because the neck may appear normal and the patient is asymptomatic until later in life. Presentation may be with neurologic deficit that occurs either spontaneously or after minor trauma. Syncopal attacks may be precipitated by sudden rotary movements of the neck. Other skeletal anomalies include cervical vertebral fusion, hemivertebrae, sacral agenesis, scoliosis (either primary or secondary) in up to 60% of cases, spinal canal stenosis, and torticollis. Other findings include webbed neck, Sprengel deformity (both, small and elevated scapula) in 30%, genitourinary abnormalities in 35 to 65% (hydronephrosis, renal ectopia, ...