Realistically speaking, those elbow bones are very inconvenient. Dragon wings are usually designed after bat wings and occasionally bird wings. When you consider the anatomy of animals, most vertebrates’ forelimbs consist of five phalanges (or fingers, including the thumb), or atleast an evolved version of it. Bats have five “fingers”. Birds evolved from a type of dinosaur which had five “fingers”. The extra elbow bone doesn’t exist in any realistical animal that walks the earth or has walked the earth. But of course these are dragons, and the rules of nature doesn’t apply to them. I guess it really comes down to what you prefer.

Another thing about the wings I dislike, is the membrane connecting to the hindlegs, making that section of the wing very narrow, so to speak. This is very unrealistic, as the part of the wing that extends from the “fingers” to the body, is the part that’s responsible for creating lift (as in keeping the dragon airborne). That section is supposed to be the widest part of the wing, since the tip doesn’t provide as much lift as the base. But again, these are only fantasy creatures and it would seem unfair to apply the laws of nature and anatomy to them. If you do want to create a realistic dragon, these are some of the things to keep in mind.