Abstract: A method of enhancing the formation of bone tissue and/or eliminating late complications subsequent to bone surgery comprising administering an amount, which is safe and sufficient to promote the formation of bone tissue and/or eliminate late complications, of a compound of formula ##STR1## wherein X is H, OH, Cl, F or a methyl group and Y is Cl, OH, --(CH.sub.2).sub.2 --N(CH.sub.3)--(CH.sub.2).sub.4 --CH.sub.3, --(CH.sub.2).sub.n --CH.sub.3 or --(CH.sub.2).sub.n --NH.sub.2, wheren is zero or an integer of 1 to 8, --NHZ, where Z is pyridinyl or cycloheptyl, --SZ', where Z' is pyridinyl or chloro-substituted phenyl, or Y is a pyridinylsubstituted lower alkyl chain; or a non-toxic, pharmaceutically acceptable salt or ester thereof to a bone surgery patient.