Klippel-Feil anomaly

Findings

There are multiple segmentation anomalies of the cervical spine, with fusion of C1-3.; left C6 hemivertebra.


Diagnosis: Klippel-Feil anomaly


Key points

Klippel-Feil anomaly refers to segmentation defects (congenital fusion) of the cervical spine.
Fusion of C2-3 and C5-6 most common
Frequently associated with Chiari malformation and syringohydromyelia.

Three categories:
- Group 1 = short, webbed neck, low hairline, complete lack of cervical segmentation
- Group 2 = isolated cervical segmentation defects
- Group 3 = segmentation defects affecting separate thoracic and/or lumbar level in addition of cervical involvement

Restricted motion at level of non-segmentation leads to accelerated disc degeneration.
50% of patients have at least partial dorsal splitting of the spinal cord. Defects in decussation of the corticospinal tracts can lead to "mirror movements" on physical exam.
Other CNS associations: occipital encephalocele, Dandy-Walker malformation, Duane syndrome, nasofrontal dermoid
Associated visceral anomalies: Sprengel deformity (20-30%, congenital elevation of the scapula, often with tethering omovertebral bone), cervical ribs, supranumary digits, tracheal and proximal bronchial stenosis, sickle sacrum, cleft palate, various renal anomalies.