I have had several pairs of one-handed shears (some by very popular
manufacturers) but they have all fallen apart within a few weeks. The
problem apears to be that the blades are attached to the handles by screws
which seat into a plastic bracket. The screws work loose and cannot be
tightened up again as the thread in the plastic bracket has worn.

Could someone please recommend a reliable brand of shears that will not fall
apart so easily?

Many thanks

Les