Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Klippel-Feil Syndrome

Basics
Description
  • Klippel-Feil syndrome is part of group of disorders characterized by malformations of the axial skeleton.
  • Specifically, this syndrome is defined by the failure of segmentation of the cervical vertebrae.
  • Its classic triad includes a low hairline, short neck, and limited neck motion.
  • Associated conditions include congenital scoliosis, Sprengel deformity, hearing impairment, synkinesis, and congenital heart disease.
  • Classification:
    • Type I: Fusions involving cervical and upper thoracic vertebrae
    • Type II: Fusions of cervical vertebrae only (several segments may be fused)
    • Type III: Type I or II with lower thoracic or lumbar vertebrae involvement
General Prevention
No known preventive measures
 
Epidemiology
  • The incidence in the general population is unknown because no screening studies have been done.
  • The anomaly develops in embryogenesis.
  • The age of presentation varies: Massive fusions usually are noted earlier (2-4 years), whereas degenerative changes present later (after age 4 years).
  • Female:Male ratio is 1.5:1.
  • Most young patients are asymptomatic and present incidentally.
  • Symptomatic stenosis tends to occur in the 4th decade of life and result in sensory or motor disturbances of the extremities.
Incidence
The incidence of congenital cervical fusions is ~0.7%.
 
Risk Factors
  • Spina bifida
  • Congenital renal anomalies
Genetics
  • This condition is phenotypically heterogeneous and may be sporadic, but familial autosomal dominant patterns have been observed.
  • Mouse model studies suggest involvement with the PAX gene families and notch signaling pathway.
  • A chromosomal inversion (q22.2q23.3) has been found to segregate with Klippel-Feil syndrome in some families.
Etiology
  • Although the cause is unknown, the prevalent hypothesis suggests that Klippel-Feil syndrome results from incomplete sclerotomal segmentation during embryologic development.
  • Other nonspecific hypotheses include abnormal facet joint segmentation, multiple or global insults to the fetus (e.g., hypoxia), and vascular disruptions or malformations.
Associated Conditions
  • Musculoskeletal: Sprengel deformity (failure of normal descent of the scapula), scoliosis (both congenital and idiopathic in up to 60% of patients), spinal stenosis, spina bifida occulta
  • Craniofacial: Hearing abnormalities, extraocular muscle palsy
  • Genitourinary: Renal abnormalities (up to 30% of patients), including unilateral renal agenesis
  • Cardiovascular: Various congenital heart malformations
Diagnosis
Signs and Symptoms
  • The clinical triad (low hairline, short neck, and limited neck motion) is seen in 40-50% of patients, with decreased neck motion in up to 75% of patients and shortening of the neck (with resulting lowering of posterior hairline) in <50%.
  • Patients also may be diagnosed after cervical spine changes are found incidentally on imaging studies.
  • Other findings may include scoliosis, deafness, and renal and cardiac anomalies.
Physical Exam
  • Careful examination of the patient focused on the cervical spine (including resting appearance, posture, and ROM) and a general neurologic examination
  • Complete physical examination to evaluate for associated anomalies in other organ systems
Tests
Imaging
  • Radiography:
    • Conventional radiographs of the cervical spine show various patterns and degrees of vertebral fusion ranging from simple block vertebrae to multiple anomalies.
      • Up to 50% show anterior, posterior, and lateral portions of vertebrae fused.
      • Fusion rates: Vertebral bodies alone, ~20% of cases; posterior fusions alone, 9%; and lateral fusions alone, 3%.
      • Spina bifida occulta often is seen.
      • Spinal stenosis at the level of the segmentation defect is observed occasionally and may develop with aging because of degenerative changes from adjacent segment hypermobility.
    • Flexion and extension radiographs are important for assessing potential instability, especially before undergoing intubation and surgery.
  • MRI will show any compression of neural elements.
  • CT-myelography is comparable to MRI in showing neural compression, but it is an invasive procedure.
Pathological Findings
  • Congenital cervical fusions, which may be associated with instability
  • Discs in the area of fusion are narrow or absent, and the remaining mobile discs show degeneration from overuse.
  • Degenerative joint disease
  • Spinal stenosis
  • Subluxation may occur over time.
Differential Diagnosis
  • Cervical fusion after a previous surgery
  • Torticollis from muscular causes
  • Cervical spinal stenosis
Treatment
General Measures
  • Evaluation of all patients with Klippel-Feil syndrome:
    • Additional evaluation for other organ system problems, including congenital cardiac, renal, or neurologic abnormalities
    • Renal imaging (a simple renal ultrasonogram)
    • Conventional flexion and extension lateral radiographs before any general anesthetic to rule out occult cervical spine instability
    • MRI scan if concern exists about neurologic involvement on a clinical basis and before any spine surgery
  • Treatment:
    • Course depends heavily on the severity of the associated renal or cardiac problems.
    • It is important to identify patients with an increased risk of neurologic injury.
    • Nonsurgical treatment includes cervical collars, bracing, and analgesics.
    • Surgical fusion is indicated when instability results in neurologic symptoms or in patients with documented (e.g., via MRI) stenosis.
    • Patients should avoid strenuous activities, contact sports, and occupations and recreational activities that increase the risk of head trauma.
Special Therapy
Physical Therapy
Indicated for general conditioning in those patients who are symptomatic from their spinal or other systemic problems
 
Medication
No role for maintenance opiates
First Line
  • Anti-inflammatory medications (as long as no gastrointestinal side effects present)
  • Enteric-coated aspirin (fewer gastrointestinal side effects)
  • Acetaminophen
Second Line
  • COX-2 inhibitors (be aware of changing side-effect profile)
  • Epidural steroids
Surgery
  • Preoperative evaluation by an internist, cardiologist, and/or anesthesiologist is necessary.
  • Other than for neurologic symptoms, surgery is indicated when nonoperative treatment fails and the patient cannot attain a tolerable quality of life.
  • Compensatory curves below the level of primary congenital fusions, whether symptomatic or not, should be monitored carefully and treated with bracing or fusion because these curves are likely to progress and cause major deformities.
  • Surgery may be required for associated anomalies, such as Sprengel deformity, scoliosis, or cervical rib resection.
Follow-up
Prognosis
Some patients develop neck pain or extremity weakness with time.
 
Complications
  • Spinal stenosis often is associated and may become symptomatic.
  • Paralysis or paraparesis may occur from cervical spine trauma in patients with extensive lesions.
Patient Monitoring
Patients should be followed regularly by an orthopaedic surgeon and by other specialists if other systems are involved.
 
Miscellaneous
Codes
ICD9-CM
756.16 Klippel-Feil syndrome
 
Patient Teaching
  • Patients should be educated about:
    • The potential for progressive motor weakness and bladder/bowel dysfunction
    • The general natural history of the condition
FAQ
Q: What is the classic triad of Klippel-Feil syndrome?
A: A low hairline, short neck, and limited neck motion.
 
Q: What are the 2 major visceral systems involved in Klippel-Feil syndrome?
A: Cardiac and genitourinary.

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