Is It Possible to Remove Long-term Scars Completely? (photo)

These white and broad scars are difficult to treat.  I would begin by a series of fractional laser treatments to improve texture and camouflage color.

Although mature scars are, by definition, permanent, there are fortunately ways to significantly improve their appearance regardless of whether they resulted from injury, infection or surgery.

When treating atrophic scars, i.e. those that are depressed below the level of the skin surface, attention must be given to the two primary aesthetically detracting aspects of these scars: the depression itself and the off-white or ivory discoloration of the surface. If the surface textrue is also crinkly or crepey, this too, must be addressed.

Subcision, which takes only minutes to perform, is a procedure carried out under local anesthetic. Once numbed, a small sterile needle is inserted below the scar and moved in all directions in order to break up the abnormal, fibrous collagen bands of scar tissue that are pulling the surface downward and causing the depression. Freed from its bonds, the surface of the scar is able to float upward toward the surface. Moreover, the procedure stimulates new, normal collagen formation (neocollagenesis) and this fresh collagen then serves as a natural buttress to hold the scar surface level with the normal surrounding skin. Optimal results are generally obtained after a series of two to four  treatments spaced at six week intervals.

For many people, just smoothing the scar in this fashion (and eliminating the shading "craters of the moon" effect) is sufficient and gratifying improvement. However, when the ivory white or off-white scar appearance remains troubling, I have found that a series of medical microneedling treatments combined with the use of an agent to enhance new pigment formation may be helpful. 

Microneedling, which may be performed either manually with a roller or a motorized device using only topical anesthesia employs an array of needles that pierce the surface of the scar to break up the surface tissue and create microchannels. This, too, allows for new collagen formation, but also makes possible the transferring (auto-transplanting) of functioning pigment producing cells from the surrounding normal area into the scar area. When this is combined with the application of tyrosine, the essential chemical involved in natural pigment production, the process of repigmenting can be enhanced. Medical microneedling, too, yields best results when performed as a series of two to four treatment sessions at six week intervals.  

When desired, subcision may be performed at the same time as medical microneedling in order to hasten the process. 

I can imagine that the scars disturb you but flat and white are things to be thankful for. Once the skin has been breached full thickness, there is always a scar. The knees, elbows, shoulders, etc. scar worse than other body areas because of the constant tension on the joints. If the white marks on your leg did not arise from a laceration, then you should see a dermatologist to evaluate whether there is another etiology. Best of luck!