The invention relates to the use of polymetaphosphates for intraarticular application for the treatment of microcrystalline arthropathies. The preparation comprises a diluent water solution and a linear or cyclic polymetaphosphate in lyophilized powder, in which the volume of diluent solution and the weight/volume ratio of lyophilized polymetaphosphate powder and diluent solution are comprised within defined fields, and the treatment is carried out by step-wise lavage, i.e. using in succession a plurality of defined portions of reconstituted solution for a joint lavage, or by continuous lavage.