Klippel-Feil Syndrome

Klippel-Feil syndrome (KFS) is when two or more of your neck bones (cervical vertebrae) are fused together. KFS leads to anomalies in the spine and can have far-reaching effects on the rest of the body.

Last Updated: February 21, 2024

Somewhere between 40,000 and 42,000 babies are diagnosed with KFS each year. It occurs at a somewhat higher rate in females than in males.

Klippel-Feil syndrome has a complex cause that has not been fully explored. The majority of cases probably occur by chance, without any clear familial or genetic link. In some people, the syndrome is brought on by a change (mutation) in a gene that normally plays a role in the formation of bones and spines.

Common signs and symptoms include:

  • Inability to turn the head freely (most common physical symptom)
  • Low hairline at the back of the head
  • A short neck
  • Left and right cheeks are noticeably different in size and shape
  • Unsteadiness in the neck and head
  • Spinal curvature, also known as scoliosis
  • Narrowing of spinal space which can compress spinal cord
  • Headaches
  • Pain that radiates down the arms or legs
  • Soreness in the muscles of the back and/or neck
  • Deafness
  • Kidney disease

KFS is diagnosed based on physical exam and imaging studies. Most of the time, this syndrome is observed in children, but sometimes it can also be seen in a fetus before birth.

MRI, X-ray, or a CT-scan is done to view the spine and check for fused bones in the neck.


Most patients who do not need surgery do well with non-invasive treatments like cervical collars, braces, and traction. Doctor may give drugs to help with pain and swelling. If a patient has a fused cervical vertebra below C3, close monitoring may only be needed.

Surgery is more likely to be needed if:

  • The brain, spinal cord, or nerves are involved
  • The spine is either crooked or unstable
  • The muscles are getting weaker

KFS worsens over time. Patients with KFS may have degenerative disk problems as they age, causing pinched nerves, back and spine discomfort, or limb weakness. They are more vulnerable to falls and strikes. It's crucial that they see their doctors on time to do checkups, testing, and imaging to determine or adjust treatment. Lastly, contact sports may not be a viable sport as these can be sources of neck injuries.


National Organization for Rare Diseases (2022). Klippel-Feil Syndrome. Retrieved December 12, 2022, from https://rarediseases.org/rare-diseases/klippel-feil-syndrome/

National Institute of Neurological Disorders and Stroke (2022). Klippel-Feil Syndrome. Retrieved December 12, 2022, from https://www.ninds.nih.gov/health-information/disorders/klippel-feil-syndrome#:~:text=Publications-,Definition,early%20weeks%20of%20fetal%20development..

Cleveland Clinic (2022). Klippel-Feil Syndrome (KFS). Retrieved December 12, 2022, from https://my.clevelandclinic.org/health/diseases/23919-klippel-feil-syndrome-kfs

Last Updated: February 21, 2024