rachidiennes

I’m not finding a widely recognized concept called "rachidiennes" in English-language sources. Could you clarify the intended context or field (for example: biochemistry related to arachidonic acid derivatives, a cultural/ethnographic group, a mathematical or historical term, or a fictional concept)? With a bit more detail, I can draft a concise, neutral wiki-style article under 300 words. If you’d like, I can also create a hypothetical or fictional entry in a neutral tone.