Klippel-Feil Syndrome

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 hair line. Other features include congenital heart defect (e.g., ventricular septal defect) and hearing loss.

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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 (born 1884), who described the disorder in 1912.

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 agnesis

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 hair line. 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, renal agenesis, horseshoe kidney, anomalies of the collecting system), congenital heart disease in 15% (particularly ventricular septal defect), deafness in 30% (conductive and/or sensorineural), synkinesia (mirror movements) in 20%, and, rarely, paraplegia or hemiplegia. Cleft palate is common, as is the association with malformation of laryngeal cartilage and mild-to-severe vocal cord paresis.

Clinical suspicion based on history and examination to assess the degree of instability. Lateral cervical radiographs in flexion-extension are essential preoperatively. Assessment of associated abnormalities at the atlantooccipital junction and presence of spinal canal stenosis or scoliosis also increase the risk of neurologic damage. Assessment of neurologic function with documentation of preexisting abnormalities. Assessment of related abnormalities, particularly of the airway in terms of difficulties with intubation, and cardiac system for evidence of congenital heart defects, cardiac failure, and possible optimization of cardiac state preoperatively. An echocardiogram may be required and cardiac surgery may be necessary as the primary procedure. Check renal function, electrolytes, and a complete blood count. Depending on the degree of scoliosis, lung function tests are recommended. A preoperative anesthesia consultation is recommended.

Patients have cervical instability and are at high risk for spinal cord injury during direct laryngoscopy, tracheal intubation, and positioning for surgery. Alternative anesthetic techniques, if possible, should be considered preferable to induction of general anesthesia with intubation. Patients should be managed as an unstable cervical spine and should have inline stabilization for laryngoscopy and intubation. Awake, nasal fiberoptic-guided intubation is the technique of choice, but is often difficult in children, especially if a pediatric-size fiberoptic bronchoscope is not available. Use of inhalational induction in a spontaneously breathing child with use of fiberoptic bronchoscope is the technique of choice in this case. Otherwise, intubation via direct laryngoscopy should be performed to ensure intubation is possible before neuromuscular blockade is given. Meticulous attention must be paid to positioning, particularly if the patient will be turned prone. Use of spinal cord monitoring showing ongoing neurologic response prevents the need for wake-up tests, which are difficult and dangerous in the presence of an unstable spine. Postoperative extubation should occur in the fully awake patient with stabilization of the neck during emergence. Associated abnormalities may have other considerations.

Preinduction use of atropine should be considered for antisialagogue activity and prior to inhalational induction. Neuromuscular blockade is relatively contraindicated because of anticipated difficult intubation until the airway is secured. Prophylactic antibiotics should be used if indicated for cardiac or renal abnormalities. With significant cardiac failure, halothane should be avoided postinduction and fluid balance should be carefully controlled.

Ullrich-Turner Syndrome: X-linked or autosomal dominant pterygium colli with limb lymphedema, short stature, skin laxity, dystrophic nails, and motor dysfunction of cranial nerves.

Cervico-Oculo-Acoustic Syndrome: Fused cervical vertebrae with torticollis, congenital deafness, and abducens palsy.