What coulf be causing radiating left leg pain from the calf to groin? I also have lower back pain along with the leg pain.

They could be part and parcel of the same injury. It is hard to say though. I would consult a doctor about it.

I've had spinal nerve problems down one leg for most of my adult life. Nothing was revealed by X ray, CAT, or MRI. A good chiropractor treated me for scarring of sacral nerves, and it helped a lot, but some of it comes back. Several conditions will show on tests, such as herniated discs. And as we age, many of us get vertebrae that collapse some as we get literally shorter.
If you have pain going up your leg, then of course you might worry about vascular problems such as clots, DVT, PAD, claudication, and several other conditions of the blood vessels.
Or a combination of nerve problems and blood vessel problems.