Newborn Chick leg deformed? Or slipped tendon

[Klaythra]

hi there, I figured I’d join the site since the last few days I’ve been on the forums searching for hours.
We hatched just one egg, the others never hatched sadly. And the one chick I thought would gain mobility after a day or so but it never did. Now that it is 3 days old I’m realizing something is wrong with it’s legs. It tries to get around but is unable to, it just wobbles back and forth and flips over and Everything.. it is unable to feed itself and now becoming more weak.
I have been force feeding it a mix of mushy chick starter, egg yolk, electrolytes, and a tiny bit of “poultry cell” for vitamins I thought it could be deficient in.
However, now as it seems to have a bit more strength, I am in desperate need of some advice, I took it to the vet, she couldn’t tell me if it was a slipped tendon.
Has anyone else gained experience in helping a baby chick recover?
Before anyone tells me to cull it, I won’t.
Im just hoping someone out there can give me some different insight as to what the problem could be and how to resolve it if possible.
I will attach some pics to show how it’s doing and what it looks like. The last photo is how it’s legs dangle in the sling I made for it, he seems to hate the sling though

 

[azygous]

If you think there's a chance the short leg is a slipped tendon, it's sure worth trying to fix it. Some time ago, I ran across instructions on fixing this issue here on this forum and I copied it and saved it. Unfortunately, I can't remember the individual that posted it, so I can't give credit where due.

Here's the instructions:

"Hold your left hand out, palm up, fingers toward the right, in front of your chest. Lay the chick's belly in your left hand, feet pointing back toward your body, overhanging your pinky finger/palm. Grasp the feet and legs between your right thumb and forefinger. Slowly lower your left hand (kinda bowling ball or lawn-dart starting motion) and let the bird dangle for just a few seconds. Twist your wrist outward, and the bird's reaction should be to lift its head/chest/body upward toward your hand. (keep your hand under, but not touching, and don't drop her! lol) When it does, you can re-grab the body. This will sometimes "reset" a slipped hip or knee joint. It won't hurt the bird, and I would think its worth a try."

Maybe the person who originally posted it will come by and recognize it and tell us so we can thank them.