Composition for hard tissue repair

A composition for hard tissue repair, comprising 24 to 58.4 parts by weight of a monomer (A), 37.9 to less than 65 parts by weight of a (meth)acrylate polymer (B) and 0.5 to 10 parts by weight of a polymerization initiator composition (C) containing an organoboron compound (c1), with the proviso that the total amount of the components (A), (B) and (C) is 100 parts by weight, and 10 to 70 parts by weight of an x-ray contrast medium, based on 100 parts by weight of the total weight of components (A), (B) and (C),

• wherein polymer (B) is a polymer mixture which comprises polymer particles (b1) having a weight-average molecular weight of 30×104 to 60×104 and a specific surface area of 1.5 to 4.5 m2/g, polymer particles (b2) having a weight-average molecular weight of 5×104 to 20×104 and a specific surface area of 0.51 to 1.2 m2/g and polymer particles (b3) having a weight-average molecular weight of 5×104 to 20×104 and a specific surface area of 0.1 to 0.5 m2/g, wherein (b1) is present in an amount of 20 to 98% by weight, (b2) is present in an amount of 2 to 80% by weight and (b3) is present in an amount of 2 to 80% by weight based on a total weight of the polymer particles (b1), (b2) and (b3), with the proviso that the total amount of polymer particles (b1), (b2) and (b3) is 100% by weight.