Collie's crusty elbows & more!

My 9yr old collie has crusty elbows and one of them now has an open wound that is very slow to heal. I bathe it twice daily with saline solution and it starts making progress then cracks open again. I put a healing balm on the new skin to try and keep it supple but it's always back to sqare one. She has a LOT of problems- Excema on her back- she's blind with cateracts-Suffers from epilepsy-and in permanently on a prescription for tablets to keep her temperature down as her blood cells fight amongst them-selves. Her litter mate brother on the other hand is a picture of rude health (touch wood!) will continue that way.
If anyone can help with any advice or tips relating to any of the above I WOULD BE VERY PLEASED TO HEAR FROM YOU. Thank-you.

If she has pressure sores (calluses) make sure that she sleeps, rests, lays on a soft bed or soft surface to relieve any pressure on her elbows. If the calluses are cracking and breaking down infection can set in. I assume you are in consultation with your vet for the other problems so mention the elbows - he/she may recommend an antibiotic or other treatment.

Sounds as though your poor girl has more than her share of troubles What are you using to relieve the eczema?

Have tried various lotions and potions some worked some didn't but of the ones that worked, they only did so short term. Botanical/homeopathic seem to work the best.
Currently she is on a vitimin supplement to help from within and pure aloe vera gel topically to soothe the skin.It's upsetting to see her like this- but nothing fazes her she's a happy little soul and believe it or non enjoys a game of frizbee with her brother who wears "bells" during the day so she knows where he is. I am lucky, in that I have a very large garden and they have the run of it all day long. She sleeps/rests on rugs or carpet also enjoys stretching out on the laminate flooring,keeps her cool I think. Tried to get her to sleep on bean bag or quilt but no joy she seems to like a firmer surface. (Thans for your reply)