Congenital Cervical Disease

By admin Last updated Nov 20, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Jeffrey B. Kreher

Basics

Uncommon group of diseases
Majority asymptomatic
May have only slight restricted cervical range of motion (ROM)
Upper cervical anomalies: More likely younger onset of instability and neurologic problems after minor trauma
Lower cervical anomalies: More likely adult presentation owing to degenerative changes in hypermobile segments adjacent to fused segments
Klippel-Feil syndrome: Most common disease: Con-genital fusion of cervical vertebrae (2 segments, congenital block vertebrae, or entire cervical spine)

Description

Craniovertebral junction diseases: Occipitoatlantal fusion, basilar impression and invagination (odontoid is more cephalad and may protrude into foramen magnum), occipital vertebrae and condylar hypoplasia, occipitoatlantal instability
Atlantoaxial anomalies: Aplasia/hypoplasia of the atlas, familial cervical dysplasia, aplasia/hypoplasia of the odontoid, os odontoideum
Lower cervical spine anomalies: Primarily Klippel-Feil syndrome
Klippel-Feil syndrome: Most common: Classic triad (congenital cervical fusion, decreased neck ROM, and short neck with low hairline) found in 50%

Epidemiology

Rare occurrence but potential for cervical spine instability and neurologic injury
Often discovered incidentally in workup of trauma, sports-related cervical cord neurapraxia, or symptomatic cervical disk disease

Prevalence

Klippel-Feil syndrome, or congenital fusion of cervical vertebrae: 0.60–0.71%:
- Most often asymptomatic and C2–3 fusion
- Next most common level C5–6 fusion
- 75% of cases C1–3
- 50% involve ≤3 vertebrae.
Prevalence of others unknown but very low
Much higher prevalence in associated conditions

Risk Factors

Trisomy 21 and Morquio syndrome (odontoid anomalies)

Genetics

Klippel-Feil syndrome:
- Can be autosomal dominant (commonly C2–3)
- Can be autosomal recessive (commonly C5–6)
- Familial form gene locus on long arm of chromosome 8
Familial cervical dysplasia: Often autosomal dominant
Mutations in the Homeobox, or Hox, genes may play a role.
Possibly due to teratologic insult (ie, maternal smoking, alcohol)

Etiology

Acute occipitoatlantal, or C1–2, instability owing to:
- Disruption of transverse atlantal ligament (runs posterior and limits excursion of odontoid into spinal cord)
- Disruption of alar ligaments (attached to odontoid and limits posterior excursion)
Chronic occipitoatlantal, or C1–2, instability (as seen in trisomy 21): Relies on checkrein effect of alar liga-ments to limit spinal cord compression by odontoid

Commonly Associated Conditions

Klippel-Feil syndrome:
- Scoliosis/kyphosis/lordosis (>50%)
- Hearing impairment (30%)
- Sprengel deformity (congenital elevation of the scapula, 25–35%)
- Genitourinary anomalies (most common unilateral renal agenesis followed by malrotation of normal kidney, 2–64%)
- Cardiovascular anomalies (more common in females, ventricular septal defect most common lesion, 4.2–14%)
- Rib abnormalities (including fusion, abnormal joints and/or spacing)
- Omovertebral bone (limits neck and shoulder movement)
- Lower cervical fusion more likely with other syndrome/condition (eg, fetal alcohol syndrome, Alpert syndrome, Crouzon syndrome, Goldenhar syndrome, cervico-oculoacoustic dysplasia, congenital cervicothoracic deformity)
Occipitocervical junction anomalies (most commonly occipitoatlantal fusion):
- Achondroplasia, diastrophic dwarfism, spondyloepiphyseal dysplasia, Larsen syndrome, Morquio syndrome
- Pes cavus/excavatum, syndactylies, jaw anomalies, cleft palate, congenital ear deformities, hypospadias
Primary basilar impression: Occipitoatlantal fusion, atlas hypoplasia, bifid posterior arch of atlas, odontoid anomalies, Klippel-Feil syndrome, achondroplasia
Occipitoatlantal instability: After trauma in trisomy 21, familial cervical dysplasia, and hyperlaxity syndromes (eg, Marfan and Ehlers-Danlos syndromes)

Diagnosis

History

Often asymptomatic or nondescript symptoms:
- Neck pain, headaches, syncope, weakness, numbness
- Wry neck (torticollis)
- Weakness, numbness, or pain in the upper extremities
- Possible transient paresis following trauma
- Possible synkinesis (mirror movements, often <5 yrs old and tends to improve with age)
Occasionally, vertebrobasilar insufficiency symptoms: Nausea, vomiting, vertigo/dizziness, seizures, mental deterioration, and syncope
Occasionally, pyramidal tract symptoms: Spasticity, hyperreflexia, muscle weakness/atrophy, and gait disturbances
Rarely, cranial nerve disturbance: Diplopia, tinnitus, dysphagia, and auditory disturbances
Rarely, posterior column disturbance: Loss of proprioception, vibration, and tactile discrimination
Occipitoatlantal fusion:
- Symptom onset usually 5th–6th decade and slowly progressive
- May be precipitated by trauma or inflammatory process
- Decreasing frequency: Pain in the occiput/neck, vertigo, unsteady gait, paresis, paresthesias, speech disturbances, hoarseness, diplopia, syncope, auditory disturbance, and dysphasia
Basilar impression and invagination:
- May not present until 2nd–3rd decade of life
- May be precipitated by minimal trauma
- Symptoms depend on impinged structures.
- Commonly, neck pain, headaches in occipital nerve distribution, and weakness and paresthesias of the limbs
- Occasionally, ataxia, vertigo, and sexual dysfunction
Nontraumatic occipitoatlantal instability: Neck pain, headache, torticollis, weakness, and vertebrobasilar symptoms
Odontoid anomalies: Hypoplasia/aplasia, os odontoideum:
- Average age at diagnosis: 19–30 yrs
- Symptomatic ∼50% of time
- Neck pain, weakness, loss of balance, transitory paresis following trauma, and myelopathy
- Few with vertebrobasilar symptoms and/or progressive myelopathy

Physical Exam

Pterygium colli, nuchal webbing:
- Shortened neck appearance when bilateral or torticollis when unilateral
- <20% in Klippel-Feil syndrome, occipitoatlantal fusion, basilar impression
Torticollis ± facial asymmetry:
- <20% in Klippel-Feil syndrome, basilar impression
- Rarely, initial flexibility at craniovertebral junction progressing to rigidity, no sensory motor cortex, tightness, and aplasia of nuchal cavity on affected side; atlas hypoplasia/aplasia
Painful (±restricted) cervical ROM: Flexion/extension generally better preserved than rotation and lateral bending
Scoliosis: Significant in 60% of Klippel-Feil syndrome patients
Radiculopathy: Nerve root irritation from osteophytes at hypermobile segments adjacent to fused vertebrae
Upper extremity weakness, numbness, or pain: More common with occipitoatlantal fusion, basilar impression
Possible long-tract signs owing to pyramidal compression:
- Long-standing spinal cord compression
- Frequent with occipitoatlantal fusion
Posterior column signs: Altered sensation to deep touch, vibration, and proprioception
Posterior impingement of occipitoatlantal fusion: Possible nystagmus, ataxia, and imbalance from cerebellar herniation
Occipitoatlantal, basilar impression: Rarely, respi-ratory and autonomic dysfunction or sudden death

Diagnostic Tests & Interpretation

Imaging

X-rays: Cervical spine anteroposterior (AP) view; open-mouth odontoid view; lateral views in neutral, flexion, and extension ± thoracolumbar posteroanterior and lateral views:
- AP: May show accessory vertebrae, especially of lateral masses or condylar hypoplasia/dysplasia
- Open-mouth: Odontoid anomalies
- Lateral neutral: Spinal stenosis (sagittal diameter of the canal and ratio of Pavlov, both limited by projection and possible abnormal vertebrae)
- Lateral flexion/extension: Translational instability (anterior or posterior translation >5 mm) or fusion (no change in distance between spinous processes)
- Thoracolumbar: Other associated spinal deformities
- In Klippel-Feil syndrome: Vertebrae widened, flattened, “wasp-waist appearance” (concave anterior and posterior cortices) ± foraminal osteophytes; absent or narrowed disk spaces possible ± posterior element fusion ± instability
- With C1–2 instability: Abnormal atlas-dens interval (ADI; ≤4 mm in children and <3 mm in adults) but not as helpful in chronic atlantoaxial instability (ie, trisomy 21, rheumatoid arthritis, or congenital anomalies), where space available for the cord (SAC), posterior aspect odontoid to anterior aspect of posterior arch atlas or posterior lip of foramen magnum is used
- In os odontoideum (or odontoid nonunion post trauma), ADI may be normal but SAC significantly reduced in flexion or extension
- In occipitoatlantal fusion, SAC ≤13 mm associated with neurologic symptoms
- With basilar impression, interpretation may be difficult owing to various techniques and associated deformities, but McGregor's line (upper surface of posterior hard palate to the most caudal point of the occipital curve) is the best screen—odontoid ≥4.5 mm above McGregor's line warrants more investigation; if the odontoid lies below McRae's line (defined by opening of foramen magnum), symptoms are less likely.
CT scan: Helpful for defining bone anatomy
MRI:
- Identifies intraspinal lesions (syringomyelia, meningioma, and lipoma) or Arnold-Chiari type I malformation (isolated or associated)
- May pick up disk protrusion, osteophytes, cord impingement, and narrowing at craniovertebral junction not seen on x-ray
- Obtain if will change clinical management

Diagnostic Procedures/Surgery

Arteriography (or MRA) if surgery is planned or if symptoms warrant (basilar impression, occipitoatlantal fusion, atlas aplasia)
Owing to increased incidence of vertebral artery anomalies

Differential Diagnosis

Neurologic abnormalities: Extensive but include cervical disk disease, congenital spinal stenosis, vascular disease, Arnold-Chiari malformation, and odontoid nonunion
Torticollis: Congenital muscular torticollis [sternocleidomastoid tumor (SMT), muscular torticollis, postural torticollis without SMT mass or tightness], ocular deficiency, hearing deficit, Grisel and Sandifer syndromes, tumor of posterior fossa, syringomyelia/Arnold-Chiari malformation, Klippel-Feil syndrome, rotatory cervical instability, infection, cervicothoracic scoliosis
Basilar impression:
- Secondary basilar impression (owing to softening of osseous skull base): Not congenital disease
- Occasionally, secondary to rickets, osteomalacia, osteogenesis imperfecta, Paget disease, neurofibromatosis, skeletal dysplasia, ankylosing spondylitis, and rheumatoid arthritis
- Occasionally, erroneously diagnosed as multiple sclerosis, posterior fossa tumors, amyotrophic lateral sclerosis, or traumatic injury

Treatment

Symptomatic treatment for headaches and occiput/neck pain not associated with neurologic symptoms
Conservative treatment such as cervical collar, braces, and traction indicated for:
- Signs and symptoms associated with C1–2 instabi-lity without posterior column signs and symptoms
- Odontoid anomalies without neurologic symptoms
- Before surgery for occipitoatlantal fusion owing to higher morbidity and mortality of surgical procedures in this condition

Medication

Analgesics (ie, acetaminophen, NSAIDs) for headache

Additional Treatment

Referral

Generally, all congenital cervical disease referred to neurosurgeon and/or neurologist for concurrent observation and management

Surgery/Other Procedures

Most common surgical indication: Posterior column signs and symptoms
Decompression of the posterior elements:
- Posterior fusion of occiput-atlas complex in occipitoatlantal fusion
- Suboccipital decompression with decompressive laminectomies of atlas and axis with posterior fusion in basilar impression
Atlantoaxial arthrodesis for odontoid abnormalities with the following:
- Myelopathy, instability of ≥10 mm in flexion and extension, progressive instability, or persistent neck pain with C1–2 instability
- Includes possible resection for os odontoideum
Arthrodesis extended (occiput to atlas) for occipitoatlantal instability
Anterior stabilization required for anterior impingement
Rarely, posterior fusion of C1–2 required for familial cervical dysplasia
Preoperative reduction with traction or positioning (atlantoaxial instability owing to odontoid anomalies):
- If neurologic symptoms reduced or alleviated, prognosis after surgery improved and used postoperative for immobilization
- Preoperative angiography of vertebral vessels for possible associated anomalies
- Especially with atlas hypoplasia/aplasia
Postoperative halo device after stabilization procedures

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

Return to play recommendations are primarily expert opinions:

Absolute contraindications to contact/collision sports: Odontoid abnormalities, occipitoatlantal fusion, Klippel-Feil syndrome with fusions above C3 (1)[C]
No contraindications for Klippel-Feil syndrome with fusion of 1 or 2 interspaces below C3, full cervical range of motion, and absence of occipital cervical anomalies, instability, disk disease, or degenerative changes (1)[C]

Patient Education

Klippel-Feil syndrome:
- Minimally affected patient can expect normal, active life with minor restrictions.
- With major areas of synostosis or high-risk patterns of cervical motion, advise patient to avoid activities that stress the cervical spine.
All congenital cervical diseases: Trauma can be catastrophic (more often with translational instability and maybe with stenotic cervical canal).

Prognosis

Klippel-Feil syndrome:

Hypermobility of upper cervical spine: Increased risk for neurologic issues
Lower cervical spine involvement: Increased risk for degenerative disease
Overall, prognosis is good, with most patients remaining relatively asymptomatic with occasional mild complaints of headaches, nonradicular weakness, and numbness.

Complications

May be absent or include paresis or sudden death

Reference

1. Torg JS, Ramsey-Emrhein JA. Management guidelines for participation in collision activities with congenital, developmental, or postinjury lesions involving the cervical spine. Clin J Sport Med. 1997;7:273–291.

Additional Reading

Guille JT, Sherk HH. Congenital osseous anomalies of the upper and lower cervical spine in children. J Bone Joint Surg Am. 2002;84-A:277–288.

Guille JT, Miller A, Bowen JR, 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.

Hensinger RN. Congenital anomalies of the cervical spine. Clin Orthop Relat Res. 1991:16–38.