Scar on knee from childhood fall. Now I'm 30 and when it's not in a bent position in sinks in and looks wrinkled. (Photo)

Although, unfortunately, as you know, scars are permanent, an indented, atrophic, crinkly scar traumatic scar can be significantly improved in appearance by a combination approach that includes subcision, the injection of biostimulatory fillers, and fractional microneedle resurfacing, a combination approach that has also proven successful for stretch marks (straie), a condition which shares many of the characteristics with the kind of scar shown in the photos.Subcision is a simple procedure that involves numbing the scar with local anesthesia, followed by the insertion of a sterile needle or trochar that is used to break up underlying scar tissue and allow for new, native collagen synthesis (neocollagenesis) to take place--the results of which are permanent.To further promote collagen production and to provide more immediate lifting of the indentation and smoothing of the surface, a small amount of biostimulatory fillers can be injected either immediately after the subcision or at a subsequent visit. Radiesse combined with Voluma XC work well for this purpose.Finally, fractional microneedle resurfacing can be performed to improve surface color and texture and help the skin to better blend with the surrounding normal skin. I prefer this approach to laser and radiofrequency treatments, since these tend to be expensive treatments and supported by far more manufacturer backed marketing hype than hard science.For more information on any of the above approaches, I recommend surfing the archives of Realself.com. Of course, be sure to seek consultation with a board certified aesthetic core physician with extensive expertise in all forms of scar treatments. 

There are a few options for treatment.  For the texture, laser or radiofrequency may help.  But for the crinkling/divit you are noticeing with movement, I would suggest fillers.  A permanent solution would be silicone and could give you a great result if injected properly.  If you are concerned, then something less permanent such as Juvederm or Restylane would be helpful.  Best, Dr. emer.