Swollen red knucle with extreme finger pain may have hit on corner of table weds night(remember saying ouch) 58 years old with osteopenia?

Need an xray: It could be a fracture so you should get an xray. If not broken then it is likely bone contusion.

Get examined: Could be a mallet finger, sattital band rupture (boxer's knuckle), or fracture. But hopefully nothing more than a contusion and/or sprain. Can't be sure without an examination and possibly an x-ray. So see your primary care physician or a hand surgeon for a comprehensive evaluation.