외상의 치유 및 합병증 = Healing and Complications of Trauma

다국어 초록 (Multilingual Abstract)

Ⅰ. Healing
Healing is accomplished either by proliferation of the parenchymal element of the injured tissue or by replacement of the damaged tissue with fibrous connective one. The former is called regeneration and the latter, repair.
There are three kinds of cells in human body; labile cells, stable cells, and permanent cells. Regeneration is confined only to the tissues containing the labile or stable cells, and the process consists basically of 1) proliferation of the original cells and migration of those cells into the damaged part, and 2) proliferation of the migrated cells.
Repair is categorized as healing by first intention and healing by second intention. Those two involve successively similar phenomena: 1) fibrinous union, 2) union by granulation tissue, 3) union by fibrous tissue, and 4) epithelial regeneration. However, in the healing by first intention scar tissue is scanty on the contrary to large scar tissue and cicatrical contraction of the wounds in the other.
repair of fractures is somewhat different from the healing of soft tissue injuries in respect of callus formation and rearrangement of the callus. Though repair of the fractures is continuous process, it is divided conveniently into four steps depending on the length of time since injury. 1) Occurence of hematoma and traumatic inflammation, 2) Organization, 3) Union by callus, and 4) Rearrangement of callus and bony union.
During the regeneration of epithelium and connective tissue injured part is occasionally replaced by fully differentiated cells of different kind to the original tissue in response to abnormal stimuli such as transformation of pseudostratified ciliated columnar epithelium of respiratory tract to squamous type, columnar epithelium of the duct of salivary gland to squamous one, and transitional epithelium of urinary bladder to squamous epithelium. Those transformation is called metaplasia Metaplasia of the above mentioned epithelium occurs rather frequently when the wound is infected. Examples of connective tissue metaplasia are frequently observed in scars with the advent of cartilagenous and bony tissues in them. Another good example is myositis ossificans in the injured muscle.

Ⅱ. Complicatoins of trauma
Clinically and medico-legally important complications of trauma may be summarized as follows; secondary infection, deep vein thrombosis and pulmonary embolism, and fat embolism.
The hazard of secondary infection should be always kept in mind in the management of the wounds. Infections of respiratory and urinary tract are frequently seen in elderly patients or in those with long bed rest after injury.
In cases of injured and fractured lower extremities deep vein thrombosis and pulmonary embolism are frequently observed. The importance of age and duration of bed rest is well ackowledged and supports the old contention that venous stasis of the lower limbs is of major pathogenic factor. Embolism judged to have caused or contributed to death is largely determined by the extent of blockage of the pulmonary arterial tree.
Fat embolism occurs after bone fracture of injury to the fatty tissue. Cerebral embolism is most likely to cause death because of widespread ischemia of the brain.
Other complications of trauma include malunion of fracture, decubitus ulcer in patients with long bed rest after injury, air embolism in divers, traumatic aneurysm of aorta, glomerular microthrombosis, and arterial thrombosis.