The pathological hypertrophic scarring enormously affects the wound healing after accidents and surgical interventions in functional and aesthetic results. This pathological scarring is an important complication in plastic surgery, for example, in case of tendon adhesions, but also known in scar-contractions in effect of hypertrophic skin scarring, or in capsular fibrosis after silicon implantation. The tendon adhesions are responsible for interference of normal hand-function and are a well-known complication after traumatic tissue irritations. This normal healing complication or pathological process is still unidentified.The present book describes the role of T-lymphocytes in cell-mediated hypertrophic immune reaction in the case of posttraumatic tendon adhesions by immunohistochemical examination of pathological tendon sheath tissues from patients in comparison to normal tendon sheath tissues from cadavers without scarring.