Klippel-Feil syndrome

Klippel-Feil syndrome consists of short neck, low posterior hairline and severe restriction of motion of the neck due to complete fusion of cervical vertebrate. [1-3] There is a wide variation in the clinical and anatomic expressions of this triad, as well as a number of associated defects in different organ systems.

The frequency of Klippel-Feil syndrome is estimated to be approximately one in 40,000, but it is probably far more common because less severe fusions remain undetected in many patients. [1] Most surveys report a female preponderance. [1,2] Although the disorder is sporadic, there are examples of familial occurrence; however, no clear mechanism of inheritance has been accepted. [1]

Pathophysiology

No proven theory exists to explain the development of congenital fusion of cervical vertebrae, and no evidence for gross chromosomal anomaly has been found. [1] Many authors have suggested that the condition arises from faulty segmentation of the mesodermal somites some time between the fourth and eighth weeks of gestation. [2]

A cross section at a lower cervical somite of a 28- to 30-day human embryo reveals marked proximity of the neural tube with paired dorsal aorta, pronephric ducts, upper limb buds and developing mesonephros. An insult at this time would not only affect the cerical spine but also might cause changes in the nearby developing organ systems.

Clinical Findings

Many persons with only minor involvement do not show the classic triad of signs. Conversely, some persons with extensive cervical involvement are often able to maintain a deceptively good range of motion. [2] Facial asymmetry (including cleft palate), torticollis and webbing of the neck are often present. [1,2] In most patients, it appears as though there is no neck at all, as if the head rests directly on the trunk. It is important to differentiate torticollis secondary to congenital changes of the cervical spine from torticollis due to muscular contracture.

Patients with Klippel-Feil syndrome may have weakness, paresthesias and pain in the arms of lower limbs. These problems may arise from central spinal stenosis of the intervertebral foramen, osteophytes or associated abnormalities of the central nervous system. [3] Syringomyelia and hemiplegia or quadriplegia, although uncommonm, are occasionally seen.

Since the disturbance production brevicollis (short neck) occurs early in embryogenesis, defects in other organ systems may occur at the same time. Common musculoskeletal anomalies that coompany Klippel-Feil syndrome include scoliosis (60 percent of cases), as well as Sprengel's deformity (elevation of the scapula), in as many as one-third of cases. Spina bifida occulta is common. [1,2] Neurologic abnormalities include extraocular muscle palsies, congenital deafness and bimanual synkinesis or mirror movements of the upper extremities. [1,2]

Cardiovascular anomalies are associated with Klippel-Feil syndrome, with varying incidence rates. Ventricular septal defects are the most common. [1,2] One-third of children with Klippel-Feil syndrome have a significant urinary tract anomaly. [2]

Radiographic Features

Although acquired fusions of the cervical spine, such as those in patients with juvenile rheumatoid arthritis or those that follow infection or trauma, may enter into the radiographic differential diagnosis, they are rarely confused with the clinical diagnosis of Klippel-Feil syndrome. [1]

Proper positioning to demonstrate lesions of the cervical vertebrae on standard radiographs is often prevented by fixed bony deformities. Overlapping shadows from the mandible, occiput or shoulders can obscure the upper vertebrae. Flexion and extension laminographic views can be helpful in evaluating the cervical deformity. In the young child, cervical fusion and narrowing of cervical disc spaces often cannot be appreciated until ossification of the vertebral bodies and end plates is complete.

Because scoliosis is often present in patients with Klippel-Feil syndrome, it should be looked for and closely mnaged (Figure 1). Another commonly associated finding, Sprengel's deformity, can easily be demonstrated on standard radiographs (Figure 2).

Treatment and Prognosis

Symptoms commonly associated with Klippel-Feil syndrome originate at the open segments adjacent to the area of synostosis. The remaining free articulations may become hypermobile due to increased stress or trauma, which can lead to frank instability as well as degenerative arthritis. [1,2] Symptoms of nerve root irritation, especially when they are mild, can frequently be relieved by traction and immobilization with a cast or collar. Decompression of the spinal cord and nerve roots is occasionally required if neurologic symptoms are resistant to conservative measures.

When cervical ribs are present, they, as well as the upper two or three thoracic ribs, can be removed surgically. [2] This not only produces apparent lengthening of the neck but also allows the upper thoracic spine to become more mobile.

The patient with minimal Klippel-Feil syndrome involvement can be expected to lead a normal life, with only minor restrictions or symptoms. However, when multiple fused vertgebrae are present (Figure 3), the remaining normal segments may become hypermobile and subject to significantly increased stress. [3] This situation can result in neural deficits after even minor trauma.

Children with Klippel-Feil syndrome have normal intelligence except when a major structural abnormality of the central nervous system coexists. [1] In the presence of more severe manifestations, such as scoliosis or internal organ involvement, early and appropriate treatment can improve the prognosis. [2]

REFERENCES

[1] Goldberg MJ. The dysmorphic child: an orthopedic perspective. New York: Raven Press, 1987:200-9.

[2] Pizzutillo PD. Klippel-Feil syndrome. In: The Cervical Spine Research Society, Editorial Committee. The cervical spine. 2d ed. Philadelphia: J.B. Lippincott Co., 1989:258-68.

[3] Elster AD. Quadriplegia after minor trauma in the Klippel-Feil syndrome. A case report and review of the literature. J Bone Joint Surg [Am] 1984;66:1473-4.

WAYNE Z. MCBRIDE, LCDR, MC, USNR is a staff physician at the U.S. Naval Medical Clinic, London, England. Dr. McBride graduated fromthe University of Osteopathic Medicine and Health Sciences, Des Moines, Iowa, and completed a residency in family practice at the Naval Hospital, Charleston, S.C.

COPYRIGHT 1992 American Academy of Family Physicians
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