You might be better off just changing the bushes in the arm rather than keep on buying a new arm every time?
Like mouse said, the bloke might mean the axial ball joint which in turn is connected to the track rod end (in most cases), this might of effected your tracking, but would probably leave un-even tyre wear (is that right?)
if the ball joint connecting hub to lower arm is shot you will want to change it asap as this can be quite dangerous in some cases..
..But perhaps you just drive it like a bastard?
