This trial is investigating the use of stem cells from the patient's own fat in treating scars from trauma, surgery or burns. The trial is being conducted by the Teheran University of Medical Sciences at their Hernat campus and proposes to recruite 60 patients with hypertrophic scars. Stem cells derived from liposuction will be injected into one half of the scar, and normal saline injected into the other half. Participants will be monitored for a year for complications following the procedure, and changes in clinical condition.