Can my indented scar be corrected, cosmetically? (photos)

Surgical scar revision with kenalog IIT can help reduce the scarring on your flank. Best,Dr. KaramanoukianLos Angeles

Thank you for sharing your question and photographs.  It is possible to replace your indented scar for a flatter incision that is more even with the surrounding skin. Be sure to see an ASPS board certified plastic surgeon in consultation to discuss. 

This scar can be improved with a combination of treatments including revision, lasers, microneedling/prp, subcision and fillers. I recommend getting a formal evaluation with a scarring expert. Best, Dr. Emer

Skin can certainly be improved - note I say improved and not removed !  Whenever there is a cut in the skin there will ALWAYS be a permanent scar, however the scar you have can be improved.
It looks like the underlying fat has either thinned out or was not repaired correctly and as such the skin is not adherent to the underlying structures.  This can be addressed by subcision and fat grafting to fill the defect out, however my preferred and more predictable recommendation would be to cut out the scar and repair the tissues in layers correctly.  This will lead to a much improved scar.