What have you needled exactly? Acupuncture or dry needling?

To me with no other causative factors besides running, I'd go with Pes anserine Bursitis.
I have treated this many times with dry needling of semitendonosis, gracillis and massaging and stretching the same musculature.
Home programme is just stretching adductors and medial hamstring. Check out other options for the older patients though as Dr Damien mentions.

Of course foot/ankle/knee/hip biomechanics also need to be checked.