Klippel-Feil Syndrome

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Klippel-Feil Syndrome

Synonyms and related keywords: low hairline, short neck, cervical spine disorder, synkinesia, Klippel Feil syndrome

INTRODUCTION

In 1912, Maurice Klippel and Andre Feil were independently the first to describe Klippel-Feil syndrome. They described patients who had a short neck, increased range of motion (ROM) in the cervical spine, and a low hairline. Feil subsequently classified the syndrome into 3 categories. Type I is described as a massive fusion of the cervical spine. Type II is present when the fusion of 1 or 2 vertebrae occurs. Type III occurs when thoracic and lumbar spine anomalies are associated with type I or type II Klippel-Feil syndrome.

Patients with Klippel-Feil syndrome usually present during childhood but may present later in life. The challenge to the clinician is to recognize the associated anomalies that can occur with Klippel-Feil syndrome and to perform the appropriate workup for diagnosis. 

Frequency: The true incidence of Klippel-Feil syndrome is unknown. No one has ever studied a cross-section of healthy people to determine the true incidence.

The incidence of Klippel-Feil syndrome has been investigated in 2 studies, using 2 different means. Gjorup reviewed all of the radiographic cervical spine films in a single hospital in Copenhagen. From these radiographs, he determined an incidence of 0.2 cases per 1000 people. Brown reviewed 1400 skeletons from the Terry collection at Washington University School of Medicine. He found an incidence of 0.71%. 

Etiology: The etiology of Klippel-Feil syndrome and its associated conditions is unknown. The syndrome can present with a variety of other clinical syndromes, including fetal alcohol syndrome, Goldenhar syndrome, and other anomalies in the extremities. Gunderson suggested that it is a genetic condition, while Gray found a low incidence of inheritance. Others have considered it to be some type of global fetal insult, which could explain the other associated conditions. Others have considered it to be caused by vascular disruption. The true etiology has yet to be determined. 

Clinical: Clinical presentation is varied because of all of the associated syndromes and anomalies that can occur in patients with Klippel-Feil syndrome. A complete history and careful physical examination may reveal some associated anomalies. From an orthopedic standpoint, most of the workup is with imaging (see Imaging Studies). 

The condition 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, decreased cervical ROM, and a low hairline, which occurs in 40-50% of patients. 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 because of cosmesis or facial asymmetry. Neurological problems may develop in 20% of patients. Pouliken found that 5 of 19 patients with Klippel-Feil syndrome had neurological involvement; of these 5 patients, 2 had neurological problems due to hypermobility at one level. Occipitocervical abnormalities were the most common cause of neurological problems (see Images 1-4). Some patients present with pain. 

Hensinger and colleagues described the constellation of anomalies that can occur with Klippel-Feil syndrome, and others have added to this list. Scoliosis occurs in approximately 60% of patients (see Images 5-6). In some patients, this is congenital scoliosis (see Image 7) due to the involvement of other parts of the thoracic or lumbar spine. Other patients develop compensatory scoliosis in the thoracic spine to compensate for the cervical or cervicothoracic scoliosis. In addition to the fusion anomalies in the cervical spine, cervical spinal stenosis can occur. While uncommon, this can increase the risk of neurological involvement. 

Anomalies of the craniocervical junction can cause instability at lower segments. Traumatic tetraplegia has been reported following minor trauma. A Sprengel anomaly occurs in 20-30% of patients (see Image 7). Always check ROM of the shoulders. Look for an omovertebral bone (see Image 8). This is an osteocartilaginous connection that tethers the scapula to the spine. An omovertebral bone ossifies with age, further limiting the ROM. A CT scan best demonstrates an omovertebral bone; however, palpation or radiographs also can detect an omovertebral bone. Other upper extremity anomalies occur less frequently. A thorough examination of the ROM and function of the upper extremity must be performed. 

Synkinesia is mirror movement of the upper extremity. Patients with this condition are unable to perform a movement of the right hand without performing the same movement of the left hand (see Image 9). This is disabling in activities of daily living (ADL). Synkinesia often may be improved with therapy and usually improves with age. 

Renal anomalies are common in individuals with Klippel-Feil syndrome, and they can be quite serious. Hensinger reviewed 50 patients, and 41 of them had an intravenous pyelogram (IVP). Renal anomalies were present in 16 (34%). Minor renal anomalies were detected in 6 individuals, including a double collecting system, renal ectopia, and bilateral tubular ectasia. Major renal anomalies were detected in 10 individuals, including hydronephrosis, absence of a kidney (see Image 10), and a horseshoe kidney. As Hensinger notes, the patient of Klippel and Feil died of renal failure and uremia. Patients with Klippel-Feil syndrome now have ultrasound as the initial test to demonstrate the presence of 2 functioning kidneys. 

Torticollis and facial asymmetry occur in 21-50% of patients with Klippel-Feil syndrome. These patients also may have a muscular torticollis. Craniofacial anomalies also can occur.

Hearing loss is common with Klippel-Feil syndrome. The hearing loss can be sensorineural, conductive (one third of cases), or mixed. Hensinger found the incidence of hearing loss to be 36%. Early audiometric evaluation and otologic evaluation are indicated in all children when the diagnosis of Klippel-Feil syndrome is established. 

Cardiovascular anomalies occur in 14-29% of cases. The most common cardiovascular defect is an interventricular septal defect. Other less common anomalies are congenital limb deficiencies, craniosynostosis, ear abnormalities, iniencephaly, and craniofacial abnormalities.

INDICATIONS

Patients with Klippel-Feil syndrome present at different ages with varying clinical presentations. Indications for the complexity of the workup vary individually. For the orthopedic surgeon, the most usual indications for surgery depend upon the amount of deformity, its location, and its progression with time. Other indications include instability of the cervical spine and/or neurological problems. These indications can occur with craniocervical junction anomalies and also when 2 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. Over one half 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.

RELEVANT ANATOMY AND CONTRAINDICATIONS

Contraindications: Since this is a syndrome with a constellation of possible abnormalities, no set of definite contraindications exists. If a surgeon believes that an operation is indicated, it is incumbent upon him/her to make certain none of the other conditions that could cause morbidity or mortality are present. Cervical or occipitocervical instability could cause increased risk during intubation. An underlying heart defect could increase anesthetic risk. An increased risk of neurologic damage during spinal fusion for correction of deformity could result from underlying spinal stenosis or spinal cord abnormality. A thorough workup of the patient is imperative prior to surgical intervention.

WORKUP

Imaging Studies:

• Plain radiography is the basis for the diagnosis of Klippel-Feil syndrome.

• Initial studies include anteroposterior (AP) and lateral views of the cervical spine.

• If anomalies are found, carefully assess the craniocervical junction to detect anomalies at that level.

• Flexion-extension radiographs are indicated if instability is suspected at the craniocervical junction or if 2 fused segments are separated by an open segment.

• Obtain plain radiographs of the entire spine to detect other spinal anomalies.

• Examine the chest to rule out involvement of the heart. Examine the chest wall for the possibility of rib anomalies, which can include multiple rib fusions. Rib fusions can be revealed with plain radiography.

• CT scan often is more useful at the spinal level.

• For patients being evaluated for surgery, CT scan with 3-dimensional reconstruction can be a very valuable tool to assess the anatomy.

• A unilateral unsegmented bar or cervical stenosis may be revealed on a CT scan, which helps the physician plan the surgical procedure.

• MRI

• MRI is indicated in patients with neurological deficits.

• Flexion-extension MRI may reveal cord compression and is useful in evaluating spinal stenosis.

• In patients with neurological deficits, obtain an MRI of the entire spine to search for central nervous system anomalies, such as a syringomyelia.

• Ultrasound initially is performed to visualize the kidneys.

• Perform intravenous pyelography if any kidney abnormality is suspected with ultrasound.

Other Tests:

• Due to the high incidence of hearing loss with Klippel-Feil syndrome, an audiologist or an otologist should evaluate all children.

TREATMENT

Medical therapy: Medical therapy is dependent upon 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 otologist. 

Surgical therapy: Surgery is indicated for a variety of situations in patients with Klippel-Feil syndrome. Due to fusion anomalies and the difference in growth potential between the 2 sides of the spine, deformity may be progressive. Instability of the cervical spine can develop because of craniocervical abnormalities. Instability of the cervical spine also can develop between 2 sets of fusion anomalies separated by normal segment. Neurologic deficits or 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. 

Koop and colleagues studied 13 cases of children who were skeletally immature with a variety of disorders that caused instability of the upper part of the cervical spine from the occiput to C5. These researchers were looking at the efficacy of posterior arthrodesis and halo-cast mobilization. Many of these patients did not have Klippel-Feil syndrome, but the surgical indications were instability. Posterior arthrodesis with external mobilization by halo-cast was carried out. In 2 of the patients, internal fixation with wire was utilized. A solid arthrodesis was obtained in 12 patients treated with autogenous bone graft. One patient treated with allograft rib developed a pseudoarthrosis. 

Koop et al cautioned that the use of wires for fixation carries risk of neural injury and often is not applicable in children with anomalous vertebra. They stress the need for delicate exposure, decortication using an air drill, and placement of autologous iliac graft. They recommended mobilization by halo-cast, which they thought would minimize the risk of neural damage and provide a reliable means of obtaining arthrodesis. 

Preoperative details: Patients must have a comprehensive workup to detect the anomalies previously mentioned. Adequate imaging studies must be obtained. Three-dimensional CT scan reconstruction often is useful. 

OUTCOME AND PROGNOSIS

The prognosis for Klippel-Feil syndrome depends on the potential anomalies. Careful evaluation, consistent follow-up, and coordination with other providers are required to avoid pitfalls and to avoid missing any diagnoses.

FUTURE AND CONTROVERSIES

The true etiology and incidence of Klippel-Feil syndrome is unknown. The syndrome can occur in association with a wide variety of anomalies. Further studies may reveal the cause. The cervical anomaly is a failure of segmentation that occurs in early fetal life. To discover a cause and devise prevention or treatment is a challenge.