**18. The pathobiology of muscular lesion**

The distinctive element which differentiates a muscular lesion and a lesion at bone level, is represented by the fact that the skeletal muscle heals through a phenomena of "repair", whereas the bone damage heals thanks to a process of "regeneration"- The main part of biological body tissue, at the moment in which it is damaged, heals through a process which hesitates in the formation of a scar area, which represents a biologically different tissue in comparison to the pre-existing one. On the contrary, when a bone segment becomes injured the regenerated tissue results identical in comparison to the pre-existent tissue. The process of repair of an injured skeletal muscle inescapably follows a constant pattern, independently of the cause which provoked the injury itself, whatever the injury may be contusion, elongation or tear (Hurme et al., 1991; Kalimo et al., 1997). In this type of process we may essentially identify three phases:


The last two phases, of repair and re-modeling, are usually associated or overlapping (Kalimo et al., 1997).
