1. A therapeutic agent for arthrosis, which contains as an active ingredient a compound represented by the formula (I): wherein R is a linear or branched alkyl group having from 1 to 30 carbon atoms, a linear or branched alkenyl group having from 2 to 30 carbon atoms, or a linear or branched alkynyl group having from 2 to 30 carbon atoms, which may contain a cycloalkane or aromatic ring； X and Y each independently represents an oxygen atom or a methylene group, with the proviso that X and Y are not simultaneously a methylene group； and Μ represents a hydrogen atom or an alkali metal atom. 2. The therapeutic agent for arthrosis according to claim 1, wherein, in the formula (I), X and Y represent an oxygen atom. 3. The therapeutic agent for arthrosis according to claim 1 or 2, wherein in the formula (I) either X or Y represents an oxygen atom and the other represents a methylene group. The therapeutic agent for arthrosis according to claim 1 or 2, wherein the compound represented by formula (I) is carbocyclic phosphatidic acid 1-oleyl cyclic phosphatidic acid, 1-palmitoleyl cyclic acid or a derivative thereof. 5. A method for treating arthrosis, comprising administering a compound represented by formula (I) to a patient with arthrosis: wherein R is a linear or branched alkyl group having from 1 to 30 carbon atoms, a linear or branched alkenyl group having from 2 to 30 carbon atoms or a linear or branched alkynyl group having from 2 to 30 carbon atoms, which may contain a cycloalkane or aromatic ring； X and Y �1. Терапевтическое средство при артрозе, которое содержит в качестве активного ингредиента соединение, представленное формулой (I):,где R представляет собой линейную или разветвленную алкильную группу, имеющую от 1 до 30 атомов углерода, линейную или разветвленную алкенильную группу, имеющую от 2 до 30 атомов углерода, или линейную или разветвленную алкинильную группу, имеющую от 2 до 30 атомов углерода, которая может содержать циклоалкановый или ароматический ци
