Klippel-Feil syndrome

Original Editor - Emy Van Rode

Top Contributors -

Emy Van Rode, Rachael Lowe, Priyanka Chugh and Evan Thomas  



The Klippel-Feil syndrome is a congenital anatomical defect in the neck, which includes fusion of two or more cervical vertebrae[1]. This syndrome is also described as congenital brevicollis syndrome[2].

Feil has classified this syndrome into 3 categories:

  1. Type I = A massive fusion of the cervical spine
  2. Type II = Fusion of 1 or 2 cervical vertebrae
  3. Type III = Type I or II Klippel-feil syndrome with thoracic and lumbar spine anomalies[3]

Epidemiology /Etiology

The klippel-feil syndrome is caused by a failure of segmentation of the cervical vertebrae during the early weeks of fetal development[2]. There have already been discussed several hypotheses concerning the origin of the abnormality. The following hypotheses are primary vascular disruption, global fetal insult , primary neural tube anomaly, genetic predisposition and at last facet joint segmentation failure. It is also possible that the syndrome is the result of maternal alcoholism, due to fetal alcohol syndrome[4].
These are just hypotheses. What exactly causes this failure of segmentation is up till now still unknown.

This syndrome is likely to have an incidence between 0.5 - 0.7% of life births, although it is difficult and almost impossible to define the exact incidence and prevalence of klippel-feil syndrome because of the major absence of population screening studies[4][5].

Characteristics/Clinical Presentation

People with Klippel-feil in general appear to have a “short neck” with a low hairline due to the fusion of several cervical vertebrae. Together with this short neck, there are skin folds passing to the shoulders, due to the fusion of the cervical spine. Because of the fusion there is also a decreased mobility in the neck. Particularly side-to-side movements and rotational movements are difficult to execute. Flexion and extension movements are also limited, but less severe[6].  This decreased range of motion is the most frequent clinical presentation[3]. Less than 50% of the patients with Klippel-feil syndrome have all three of these signs[5].

It is possible that complications occur by injury of the spinal cord. Symptoms are numbness, paresthesia, spasticity or paralysis. These complication can occur in a person with Klippel-feil syndrome by a minor fall, stumble or knock[6]. This syndrome can also lead to chronic symptoms like neck- and extremity pain, weakness, ataxia, headaches, vision – or hearing problems and vertigo[4].

Patients with type II KFS are likely to have an increased curvature develop of the spine in the sagittal plane. Patients with type I and III have a higher risk for development of scoliosis[5].  Torticollis or facial asymmetry can occur in 21-50% of the patients with KFS. It is important to make a differential diagnosis between congenital muscular torticollis and Klippel-Feil syndrome. To differentiate these two, radiographic plains have to be made, but in little children it is hard to do so, especially of the craniocervical junction. Anomalies of the craniocervial junction could cause instability at lower segments[3]

Several studies showed that the syndrome can present with other clinical symptoms. These are the following: Goldenhar syndrome, anomalies of the extremeties, scoliosis, torticollis, facial nerve paralysis, Chiari I malformation, Syringohydromyelina, High-arche palate and Duane’s contracture of the lateral rectus muscle[7][4].

Between 30 and 60% of patients with Klippel-feil syndrome have genito-urinary problems. These problems are mainly situated at the level of the kidneys. These patients could have a unilateral renal agenesis, malrotation of the kidney, ectopic kidney, horseshoe kidney and renal pelvic and ureteral duplication. Besides kidney problems these patients can also present with genital abnormalities. Unilateral renal agenesis is the most common anomaly among patients with KFS[4].

Differential Diagnosis

  • Wildervanck syndrome or cervico-oculo-acoustic syndrome.

Patients with KFS can present with deafness, so it is important to differentiate the Klippel –feil syndrome with the Wildervanck syndrome.

  •  Congenital scoliosis - Numerous patients with KFS are likely to have congenital scoliosis. KFS is mostly discovered when patients undergo radiography for scoliosis.
  • Postinfection/ spine inflammatory disorders due to acquired spinal fusion.
  • Mayer-Rokitansky-Kaster-syndrome
  • Torticollis - It is important to make a differential diagnosis between muscular congenital torticollis and Klippel feil syndrome. More than 20% of the patients with KFS present with Torticollis.
  • Sprengel’s deformity - Exists in 16 % of patients with KFS, but can also present without KFS. So it must be verified if a patient with Sprengel’s deformity also presents with KFS.

Diagnostic Procedures

Patients with KFS have a cervical deformation at birth, but are usually diagnosed at later age[5].  Some patients are diagnosed while undergoing radiography for other reasons related or even not related to this syndrome[2] This syndrome is usually diagnosed when the presentation of complaints occur. The most important complaints are pain and neurologic symptoms[5]

Neurologic exams are designated when neurologic symptoms appear[4]. In addition, Radiographic evaluation is necessary to determine the diagnosis of klippel-feil syndrome.
Spinal fusion can be documented by plain films and CT-scans, only with combined myelo-CT or rather a magnetic resonance image (MRI)[2]. An MRI including flexion and extension MRI is designated when complaints of instability and/or spinal stenosis (LINK) appear. Instability associated with an adjacent fused segment can be tested with translation of the vertebral corpus on another. Pseudoluxation of C2 on C3 or C3 on C4 is a normal phenomenon in children with KFS younger than the age of 8 years[5].

Magnetic resonance imaging can give valuable information about the space available for the spinal cord, determination of spinal stenosis caused by the deformation, and CSN abnormalities like; Syrinx, tethered cord, or diastomyelia. It is also used to determine if the cervical maformation compresses the brain, brainstem or the spinal cord[5].

Physical Examination

The clinical presentation of Klippel-Feil syndrome is varied because of the different associated syndromes and anomalies that can occur in patients with this syndrome. In children in particular, the classic clinical triad of manifestations (see Background) may not all be present.
A complete history and careful physical examination may reveal some associated anomalies. From an orthopedic standpoint, most of the workup involves imaging.
Klippel-Feil syndrome is detected throughout life, often as an incidental finding. Patients with upper cervical spine involvement tend to present at an earlier age than those whose involvement is lower in the cervical spine. Most patients present with a short neck and decreased cervical range of motion (ROM), with a low hairline occurring in 40-50% of cases. Decreased ROM is the most frequent clinical finding. Rotational loss usually is more pronounced than is the loss of flexion and extension.
Other patients present with torticollis or facial asymmetry. In very young children, it is important to differentiate congenital muscular torticollis from Klippel-Feil syndrome. It is often difficult to obtain good plain radiographs of young children with torticollis, especially radiographs of the craniocervical junction. Neurologic problems may develop in 20% of patients. Gray found that 27% developed symptoms in the first decade.
Rouvreau found that five of 19 patients with Klippel-Feil syndrome had neurologic involvement; of these five, two had neurologic problems resulting from hypermobility at one level. Occipitocervical abnormalities were the most common cause of neurologic problems . Some patients present with pain.[8]

Medical Management

For the orthopedic surgeon, the most frequent indications for surgical treatment of Klippel-Feil syndrome depend on the amount of deformity, its location, and its progression with time. Other indications include instability of the cervical spine and/or neurologic problems. These indications can occur with craniocervical junction anomalies and when two fused segments are separated by a normal segment.
Some patients present early in life with complex cervical and cervicothoracic deformity that is progressive and disfiguring. Some of these patients require cervical spine fusions to prevent progression.
Other patients may develop compensatory or associated congenital scoliosis, which also can be progressive over time and requires fusion to prevent progressive deformity. More than 50% of the patients in Hensinger's study had scoliosis. Treatment of the scoliosis with bracing or surgery was required in 18 of the 50 patients.
Using their own classification system, Samartzis et al reviewed 28 patients radiographically and clinically (mean age at presentation, 7.1 years; mean age of symptom onset in symptomatic patients, 11.9 years; mean follow-up, 8.5 years).  Of the 28, 64% had no symptoms, two developed myelopathic symptoms (type II and type III), and two developed radiculopathic symptoms (type II and type III). Axial symptoms were more common in type I patients. The investigators recommended activity modification in high-risk patients.
The same authors reported on a patient who developed a symptomatic cervical disc herniation. The patient had occipitalization of C1 and fusion of C2-3 and C4-T1. This left only C3-4 as a hypermobile segment; thus, the patient was at high risk. The patient was treated successfully with a same-day, combined anteroposterior (AP) procedure.
Theiss et al reviewed 32 patients with congenital scoliosis followed for more than 10 years. Only seven (22%) developed cervical or cervical-related symptoms, and only two required surgery for their cervical-related symptoms. No fusion pattern was identified that placed the patients at greater risk for developing symptoms.
Because Klippel-Feil syndrome is associated with a constellation of possible abnormalities, no set of definite contraindications for surgery exists. If a surgeon believes that an operation is indicated, it is incumbent upon him or her to make certain that none of the conditions that could cause morbidity or mortality are present.
Cervical or occipitocervical instability could increase the risk of neurologic damage during intubation. An underlying heart defect could increase anesthetic risk. An underlying spinal stenosis or spinal cord abnormality could increase the risk of neurologic damage during spinal fusion for correction of deformity. A thorough workup of the patient is imperative prior to surgical intervention.Medical therapy for Klippel-Feil syndrome depends on the congenital anomalies present in the syndrome. Primary care physicians may not be familiar with all of the possible associated anomalies. Patients with genitourinary abnormalities are referred to a nephrologist or urologist. Patients with cardiovascular abnormalities are cared for by a cardiologist or primary care physician. Patients with auditory abnormalities are referred to an audiologist or an otologist.

Surgical treatment of Klippel-Feil syndrome is indicated in a variety of situations. As a result of fusion anomalies and the difference in growth potential of the anomalous vertebral bodies, deformity may be progressive. Instability of the cervical spine can develop because of craniocervical abnormalities. Instability of the cervical spine can also develop between two sets of fusion anomalies separated by a normal segment.
Neurologic deficits and persistent pain are indications for surgery. Development of a compensatory curve in the thoracic spine may require surgical intervention or bracing. Symptomatic spinal stenosis may require decompression and fusion.
Preoperatively, patients must have a comprehensive workup to detect the various anomalies that may be present (see Workup). Adequate imaging studies must be obtained. Three-dimensional (3D) computed tomography (CT) reconstruction often is useful.

Physical Therapy Management

Klippel-Feil syndrome cannot be resolved with physical therapy. Nevertheless physical therapy in combination with non-steroidal medications could be useful to prevent degenerative changes. When a patient has several fused vertebrae like in Klippel-Feil syndrome, the risk of osteoarthritic changes is increased because of the immobile joint. It is likely that the superior joint undergoes degenerative changes with formation of osteophytes. This can lead to Radiculopathy and/or myelopathy, therefore the goal of physical therapy is to prevent or to delay this damage. If physical therapy does not work, surgical management is necessary to relieve compression on the nerve roots[9][10].

Recent Related Research (from Pubmed)


  1. J. D. AUERBACH, H. S. HOSALKAR. Spinal Cord Dimensions in Children With Klippel-Feil Syndrome, A Controlled, Blinded Radiographic Analysis With Implications for Neurologic Outcomes. SPINE. 2008, Vol. 33 ; Nr. 12, p 1366–1371. Level of evidence: 1B
  2. 2.0 2.1 2.2 2.3 NATIONAL ORGANISATION FOR RARE DISORDERS (2003). Guide to rare disorders. Philadelphia: Lippincott Williams & Wilkins. Level of evidence: D
  3. 3.0 3.1 3.2 J. A. SULLIVAN, MARY ANN E. KEENAN (update 2011). Klippel-Feil syndrome. http://emedicine.medscape.com/article/1264848-overview. Level of evidence: 2A
  4. 4.0 4.1 4.2 4.3 4.4 4.5 A. L. ALBRGIGHT, P. D. ADELSON, IAN F. POLLACK. Principles and practice of pediatric neurosurgery. New York: Thieme medical publishers. Level of evidence: D
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 M. R. TRACY, J. P. DORMANS, K. KUSUMI. Klippel-Feil Syndrome: Clinical Features and Current Understanding of Etiology. Clinical orthopaedics and related research. 2004; Nr. 424, pp. 183–190. Level of evidence: 2C
  6. 6.0 6.1 PATRICIA GILBERT(2000). A-Z of syndromes and inherited disorders. Cheltenham (UK): Nelson Thornes. Level of evidence: D
  7. NEIDENGARD L., CARTER TE., SMITH D.W. Klippel-Feil malformation complex in fetal alcohol syndrome. Am J Dis Child. 1978; Nr. 132(9), pp. 929-30. Level of evidence: 4
  8. http://emedicine.medscape.com/article/1264848-clinical
  9. AN H. S., SIMPSON M. J. (1994). Surgery of the cervical spine. London: Martin Dunitz Limited. Level of evidence: D
  10. TOLLISON D.C., SATTERHTWAITE J.R. (2002). Practical pain management. Philadelphia: fckLRLippincott Williams & Wilkins. Level of evidence: D