I injured my lower back pushing a car out of snow. I had a back x-ray, is showed mild osteophytosis in the thoracolumbar spine, what does that mean?

Osteophytosis? The term means you have multiple bone spurs along the spine segment you had xrayed. Alone, osteophytes are not particularly worrisome. They document wear ; tear on your back which should be no surprise if you are pushing cars and are 67. If you have local back pain you probably more likely have a muscular injury from exertion. If pain radiates into legs, MRI would be more helpful.