|He seems to have an injured knee, but was walking without a limp.|
Deer grow their first set of antlers when they are approximately one year of age. (IWLA)
The antlers start growing in the spring, as the days are lengthening. At this stage, they are bones covered by a soft, nutrient-rich skin, called velvet. In the fall, the skin will dry and fall off, leaving only the hard bone. Later still, the knobby part at the base will deteriorate, and the antler will fall off. Next year's antlers will probably be bigger than this year's.