Endorrhachis is a medical term used to describe an abnormality in the vertebral column. The word is pronounced en-doh-RAK-iss and is spelled as follows in IPA phonetic transcription: /ɛndɔrækɪs/. The first syllable is pronounced as "en" and rhymes with "pen." The second syllable is pronounced as "doh" and rhymes with "so." The third syllable is pronounced as "rak" and rhymes with "back." The final syllable is pronounced as "iss" and rhymes with "bliss."
Endorrhachis refers to a congenital condition where the spinal cord is located entirely within the vertebral column, instead of extending beyond it. The term derives from the combination of the Greek words "endo," which means within, and "rhachis," which means spinal cord. This rare anatomical anomaly involves the abnormal development of the neural tube during embryonic development.
In individuals with endorrhachis, the spinal cord fails to separate from the surrounding vertebrae, remaining enclosed within the bony structures of the spine. As a result, the spinal cord does not exit at the lower end of the vertebral column as it does in a typical anatomy. Instead, it terminates within the vertebral canal, often resulting in a conus medullaris that is significantly lower in position compared to normal.
Endorrhachis may lead to various associated abnormalities, such as dysraphic defects or malformations in the spinal column, including spina bifida. Additionally, it can result in neurological complications due to the altered positioning and limited growth of the spinal cord within the vertebral canal.
Due to its rarity, endorrhachis remains poorly understood, and treatment options are limited. Management mainly focuses on symptomatic relief and preventing secondary complications, such as infections or tethered spinal cord syndrome. Surgical intervention may be required to correct associated spinal abnormalities and alleviate neurological symptoms, although the complexity of the condition often poses challenges for treatment.
Lining membrane of the spinal canal, spinal dura mater.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The term endorrhachis comes from the Greek words endo meaning within and rhachis meaning spine or backbone. Therefore, endorrhachis can be translated as within the spine or inside the backbone.