Klippel Feil Syndrome

Key Points:


Klippel-Feil syndrome is defined as fusion of multiple cervical vertebrae. The condition was first reported in 1912 by Drs. Klippel and Feil when they described a patient with a short neck, low posterior hairline and restricted neck range of motion (Hensinger, 1974). These characteristics are considered to be the classic triad in this patient population. All three characteristics may not all be present in up to 50% of cases (Samartzis, 2016). Multiple extra-spinal manifestations may coexist with this condition.


This syndrome is estimated to occur in 1 in 40,000 to 42,000 newborns worldwide, though the actual prevalence may be higher due to undiagnosed cases (Samartzis, 2007).

Clinical Findings:

Children classically present with a short, webbed neck, low posterior hair line, and limited neck range of motion. Torticollis and restricted cervical spine range of motion is the most consistent finding. Even with multiple congenital fusions, however, these patients can maintain deceptively good motion (Hensinger, 1974). Patients are frequently asymptomatic and the condition is discovered incidentally. Asymptomatic patients may eventually develop pain or neurologic symptoms from adjacent level degenerative changes or instability (Copley, 1998). Facial asymmetry, torticollis, Sprengel’s deformity (42%), scoliosis (50-79%), genitourinary (33%) and cardiovascular (14%) abnormalities, deafness (30%) and synkinesia (75%) may also be present (Hensinger, 1974; Copley, 2014; Samartzis, 2007).

Imaging Studies:

Proper radiographic evaluation of the cervical spine is necessary to fully evaluate the deformity. Initial radiographic evaluation should include anteroposterior and lateral images with the neck in neutral, flexion and extension. (Figure 1)  Positioning for radiographs may be difficult due to torticollis and restricted range of motion resulting in images with obscured landmarks due to overlap of the mandible and other structures.  In this setting, a lateral radiograph of the skull may improve visualization of the occipitocervical junction.  

Evaluation of the occiput-C1 relationship, screening for basilar invagination, and assessment of stability is critical (Copley, 2014). Various radiographic lines and parameters (Chamberlain, McRae, McGregor, SAC & ADI) have been described to assist with interpretation of these images (Copley 1998; Copley, 2014). (Figure 2) When accurate anatomy is difficult to ascertain on x-ray, CT can be utilized to better define the osseous deformity. (Figure 3)

At the time of initial diagnosis, screening for associated anomalies in the cardiac and genitourinary systems should be completed.  A general pediatric evaluation for congenital cardiac disease is appropriate and an echocardiogram may be considered.  A renal ultrasound is an excellent screening test for genitourinary anomalies.   A screening spine MRI from the craniocervical junction to the sacrum to evaluate for basilar invagination, Chiari I malformation, syringomyelia and tethered cord can be considered at presentation. (Figure 4)  

The Samartzis classification scheme can be used to describe the fused segments. Type I consists of a single congenitally fused block; Type II is multiple non-contiguous congenitally fused blocks; and Type III is multiple contiguous congenitally fused blocks (Samartzis, 2006).


Intermittent clinical and radiographic monitoring is performed for skeletally immature patients with Klippel-Feil syndrome.  Activity modification and restriction is appropriate in the setting of multiple cervical fusion anomalies with a limited number of motion segments. In particular, contact sports (football) or those where forced cervical flexion can occur (gymnastics, wrestling, etc.) should be avoided.

Operative treatment is reserved for progressive deformity, instability, or neurologic compression.  In the setting of progressive deformity, arthrodesis is appropriate to prevent further growth of the anomalous vertebra. Anteroposterior fusion is considered in younger children to prevent the crankshaft phenomenon.   Instability is also treated with arthrodesis.  Anterior brainstem or spinal cord compression may require transoral resection of the dens in combination with a posterior occiptocervical arthrodesis.  Posterior compression may require posterior craniectomy and/or laminectomy in addition to a posterior arthrodesis.

Halo fixation may assist with correction of flexible deformities and provide post-operative immobilization after an arthrodesis. Care must be taken to ensure pins are placed in areas where skull is the thickest and with the appropriate torque for the child’s age (Copley, 2014). CT imaging of the skull can be helpful in some cases to plan halo ring placement.


Sudden death is the most serious complication that may result from neurological compression and must be considered when weighing treatment options (Copley, 1998). Advanced imaging of the cervical spine should always be performed on these patients prior to any planned operative procedure to ensure there are no additional precautions necessary during induction of anesthesia or positioning. This patient population is also at an increased risk for neurological injury following minor or major trauma (Samartzis, 2007). 

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  1. Copley, L. Disorders of the Neck. In: Tachdjian’s Pediatric Orthopaedics. 5th ed. Philadelphia, PA: Elsevier; 2014:167-205. 
  2. Copley L, Dormans J. Cervical Spine Disorders in Infants and Children. J Am Acad Orthop Surg. 1998;6:204-214.  
  3. Guille J, Miller A, Bowen J, et al. The Natural History of Klippel-Feil Syndrome: Clinical, Roentgenographic and Magnetic Resonance Imaging Findings at Adulthood. J Pediatr Orthop. 1995;15:617-626. 
  4. Hensinger R, Lang J, MacEwen G. Klippel-Feil Syndrom: A Constellation of Associate Anomalies. J Bone Joint Surg Am. 1974;56A(6):1246-1253. 
  5. Lowry, RB. The Klippel-Feil anomalad as part of the fetal alcohol syndrome. Teratology. 1977;16:53-6.
  6. Neal K, Mohamed A. Atlantoaxial Rotatory Subluxation in Children. J Am Acad Orthop Surg. 2015;23:382-392. 
  7. Samartzis D, Kalluri P, Herman J, Lubicky J, Shen F. “Clinical triad” findings in pediatric Klippel-Feil patients. Scoliosis and Spinal Disorders. 2016;11:15. 
  8. Samartzis D, Herman J, Lubicky JP, Shen FH. Classification of congenitally fused cervical patterns in Klippel-Feil patients: epidemiology and role in the development of cervical spine-related symptoms. Spine. 2006;31:E798-804. 
  9. Samartzis D, Lubicky J, Herman J, Shen F. From the Clinic and Imaging Suite. Klippel-Feil Syndrome and associated abnormalities: the necessity for a multidisciplinary approach in patient management. Spine J. 2007;7:135-137.
  10. Sankar W, Weiss J, Skaggs D. Orthopaedic Conditions in the Newborn. J Am Acad Orthop Surg. 2009;17:112-122.

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