It would be best to replace them as a pair, unless the other side has been serviced recently. At that age, odds are that the balljoints and bushings are "up" for renewal.
You could rebuild the arm that is not damaged, though some have said the cost is about the same if a mechanic does it. I did it myself, and the related parts were only around $80.
If you do both sides, you can set the alignment, and forget about pulling springs for the next 100k plus (unless you hit something else)
