in the USA, the term "spats" is archaic

Oh Gawd! You're making me feel old, *old, OLD!!!!!
Could not find "spats" on the Shorter OED-CD or through Atomica.
However, Webster's New World Dictionary of the American Language (1978) has "spats" defined as noun (Colloq)<spatterdash - a legging a gaiterlike covering for the instep and ankle.
My Dad wore spats which were made of a soft felt in colors to compliment or contrast with the shoe/trouser color. They buttoned on the outside of the instep and protected the shoe top and ankle and provided some warmth in winter.
Only place I see them now is in "period" movie dramas.
But there is no other word that is specific to them
Is it because spats are no longer in fashion that the word has become archaic?
That is until some designer revives spats as a fashion statement or fad?
wow