5. Physical Injuries.docx

PHYSICAL INJURIES Rey J. Millena, MD, MCHM, FPCAM Legal Medicine Physical Injuries Secondary to Physical Violence Physical Injury = Wound The effect of the application of physical violence on a person is the production of wound. WOUND = Kinetic Energy X Time X Area X “other factors” Vital Reaction Vital Reaction is the sum total of all reactions of tissue or organ to trauma. These are the common reactions of living tissue to trauma: 1. Rubor – redness or congestion due to increase of blood supply as a repair mechanism. 2. Calor – sensation of heat or increase in temperature. 3. Dolor – Pain due to involvement of sensory nerve. 4. Loss of function – tissue may not be able to function normally due to the trauma. Classifications of Wounds 1. As to severity: a. Mortal wound b. Non-mortal wound 2. As to the Kind of Instrument Used: a. Blunt instrument (contusion, hematoma lacerated wound) b. Sharp instrument 1) Sharp-edged (incised wound) 2) Sharp-pointed (punctured wound) 3) Sharp-edged & sharp pointed (stab wound) c. Tearing force (lacerated wound) Change of atmospheric pressure (barotraumas) Heat or cold (frostbite, burns or scald) Chemical explosion (gunshot or shrapnel wound) Infection e.g. Tropical ulcer (anthrax infection of skin) 3. As to Manner of Infliction: a. Hit b. Thrust or stab c. Gunpowder explosion d. Sliding or rubbing or abrasion 4. As Regard to the Depth of the Wound: a. Superficial – involves only the skin b. Deep – involves the inner structure beyond the skin 1) Penetrating - piercing a solid organ or enters the body but did not come out. 2) Perforating – piercing hallow organ or traversing completely a part of the body. 5. As regards to the Relation of the Site of the Application of Force and the Location of Injury: a. Coup injury – injury at the site of application of force. b. Contre - Coup injury – injury found opposite of the application of force. c. Coup Contre - Coup injury d. Locus Minoris Resistencia – injury at the area of least resistance. 6. As to the Regions or Organs of the Body Involved. 7. Special Types of Wounds: a. Defence wound b. Patterned wound – wound in the nature and shape of an object that cause the injury. c. Self-Inflicted wound – injury produced on oneself without the intent to end life. 1

Motives of Producing Self-Inflicted Wounds: 1 – To claim pension, workman’s compensation or insurance. 2 – To escape obligation or punishment. 3 – To destroy the existing identity in order create a new one. 4 – To gain attention and sympathy. 5 – Psychotic behaviour. Type of Wounds: A. Close Wound – there is no breach of continuity of the skin or mucous membrane. a. Superficial 1) Petechiae – circumscribed pinhead size hemorrhage e.g. Insect bite. 2) Contusion – bruising, wound in the skin and subcutaneous tissue due to extravasations of blood.The shape may follow the wounding weapon, so that the position of the bruise may indicate the manner of assault. 3) Hematoma – an accumulation of blood in a newly formed cavity within the tissues that clots to form a solid swelling usually due to trauma. Abscess, gangrene, fibroid thickening and even malignancy are possible complications. B.

Deep 1) Musculo-Skeletal Injuries a) Sprain – injury to ligament, caused by sudden overstretching. b) Dislocation – loss of contact of joint surface. c) Fracture – breakage of bone. (1) Simple fracture (2) Compound fracture – w/ open* wound extending to fracture site. (3) Comminuted fracture – fragmented w/ separation of bone. (4) Pathologic fracture – due to diseaserather than violence. d) Strain – injury to a muscle by overstretching of overworking. e) Subluxation – partial dislocation of a joint, bone ends are mis-aligned but still in contact. 2) Internal Haemorrhage a) Intra-cranial hemorrhage – bleeding in the cranial cavity. b) Rupture of organ – injury of hollow organ inside the body. c) Laceration of an organ 3) Cerebral concussion – condition of the brain resulting from a sudden jarring of the head, characterized by headache,dizziness, confusion, semi-consciousness to unconsciousness, and amnesia (retrograde).

C.

Open Wounds: a. Abrasion – removal of the superficial epithelial layer of the skin caused by a friction against a hard rough surface. -develops at the precise point of impact of the force causing it -injury consist of parallel linear injuries that are in line with the direction of the friction causing it -may exhibit the pattern of the wounding instrument -usually does not require medical treatment but with medico-legal importance e.g. Abrasion by fingernails may indicate struggle or assault. Forms of abrasion a. Linear – appears as a single line, may be curve or straight. b. Multi-linear – several linear marks parallel to one another. c. Confluent – linear marks indistinguishable on account of the severity of friction and roughness of the object. d. Multiple – several abrasion of varying sizes and shapes found in different parts of the body. Types of abrasion: Scratches – caused by the sliding sharp pointed instrument over the skin e.g. Pin, thorn or finger nail. Grazes – due to forcible contact with a rough, hard object resulting to irregular removal of the skin surface. 2

Impact or imprint abrasion – due to contact with rough, hard object in which the structural form of the object is reflected over the skin. Pressure abrasion – caused by pressure accompanied by movement usually observed in hanging. The spiral strands of the rope may be reflected on the skin of the neck. b. Incised wound – produced by sharp edged or sharp linear edge of instrument. -impact cut when there is forcible contact of the cutting instrument. -slice cut when injury is due to the pressure accompanied with sliding movement of the instrument. Characteristics of incised wound a. Edges are clean cut and extremities are sharp. b. Wound is straight and may be shelving if instrument is applied at acute angle to the surface of the body. c. Usually shallow near the extremities and deeper at the middle portion. d. Profuse bleeding is often due to clean cut blood vessels. e. Gaping is due to the retraction of the edges depending on the direction of the wound with the line of cleavage (Langer’s line). f. Covering clothing will show clean cut over the wound. Healing is relatively fast w/out complication or deeper involvement. Incised wound made by glass may have particles of glass in the wound. Determination whether: Suicidal – located where major blood vessels are found and conveniently accessible to the inflicting hands. Usually with hesitation cuts and direction of cuts depends on the location and the hand used. Homicidal – located both in accessible & non-accessible parts of the body to the hands of injured. Clothing is usually included & there may be presence of defence and other forms of wounds. c. Accidental – multiple incised wound is commonly seen in vehicular accidents due to the broken windshield and glass windows, in using the kitchen knives while cooking, etc...usually depending on the instrument used by the trade. c. Stab Wound – produced by penetration of sharp-pointed and sharp-edged (bladed) instrument. In describing must include: 1. length of skin defect, tailing measured and described separately. 2. condition of extremities 3. condition of the edges – clean cut or serrated. 4. linear direction of surface wound – vertical, horizontal, oblique to right or left. 5. location – region of the body & measurement from anatomical landmark. 6. direction of penetration – tri- dimensional. 7. depth of penetration 8. tissue and organ involved Determination whether: Suicidal - located over vital parts of the body - usually solitary, if ever multiple only in one location. - accessible to the hands of the suicidal person. - hands smeared with blood. - instrument used is in the hands of the person. - suicidal note present. - presence of motive for suicide. - no disturbance in the scene. Determination whether: b. Homicidal – most common. - presence of other forms of injuries. - located in any part of the body. - usually more than one stab wound. - usually there is motive for stabbing. - usually there is disturbance in the crime scene. c. Accidental stab wound – are rare. Medical evidence to show the intent to kill the victim: 3

- more than one stab wound. - inflicted on vital parts of the body. - serrated edges. - irregular or stellate shape of skin defect. *most common cause of death is hemorrhage. d. Punctured wound – due to a thrust of sharp pointed instrument. Characteristics: - nature of external injury depends on sharpness and shape of instrument, maybe small or unnoticeable due to elasticity of skin & clotting of blood. - external haemorrhage limited. - sealing of wound is conducive for anaerobic microorganism. Medical evidence to show it is homicidal: - same as stab wound except for serration and stellate defect of skin injury. As suicidal: - same as stab wound. e. Lacerated wound – is a tear of the skin and the underlying tissues due to forcible contact with blunt instrument. Characteristics: - shape & size of injury not correspond to the inflicting instrument. - usually developed on where bones are superficially located. - edges is rugged with extremities irregular and ill-defined. - borders of wound is contused & swollen. - bridging of tissue joining the edges and hair bulbs intact. - bleeding not extensive. - healing process is delayed. Classification of lacerated wound: 1. Splitting – crushing of skin between 2 hard objects. 2. Overstretching e.g. Avulsion – the remaining tissue is that of laceration. 3. Grinding compression 4. Tearing or cut laceration – produced by heavy cutting blunt or semi-sharp edge instrument, like chopper. Lacerated wound maybe accidental or homicidal but rarely suicidal. Differentiate lacerated wound from incised wound as to: - edges - extremities - healing - scar formed - inflicting instrument Factors for the severity of wounds: Hemorrhage a. Loss of blood incompatible with life. b. Increase pressure in or on the vital organs to affect functioning, e.g. Intracraneal hemorrhage, cardiac tamponade, etc. c. Mechanical barrier to affect functioning, bleeding in the tracheo-broncheal lumina, epistaxis, hemoptysis. Causes of hemorrhage* 1. Trauma 2. Natural causes: - Stroke/cerebro-vascular accident - rupture of aneurism - rupture of esophageal varices - pulmonary hemorrhage due to PTB, lung abscess, ca 4

- rupture of ectopic pregnancy - rupture of enlarge spleen in malaria, typhoid fever 2. Size of injury – bigger wounds are more exposed to infection and effects of environment. 3. Organs involved – if vital organs. 4. Foreign body or substance introduced in the body – may be toxic or may act as physical irritant, e.g. Pathogenic organism, chemical (cyanide, nicotine, mercury), toxins (venoms) 5. Absence of medical or surgical intervention. Fatal Effects of Wounds 1. Directly Fatal Due to: a. Haemorrhage b. Injuries on the vital organs c. Electrolyte imbalance 2. Indirectly Fatal Due to: a. Secondary haemorrhage following sepsis b. Specific infections, e.g. Tetanus, gas gangrene c. Scarring effect e.g. Strictures, adhesions d. Embolism Healing of Wounds Regeneration of human tissue -capacity for regeneration decreases as age increases. -state of nutrition affects the capacity to regenerate. -more highly specialized tissue the less capacity to regenerate Rapidly regenerates: -connective tissues -blood forming tissues -surface epithelium of skin Limited capacity to regenerate: -smooth muscle cells -neurons of the central nervous system -specialized organs Factors affecting the time of healing: Vascularity Age of person State of nutrition of person Degree of rest or immobilization Nature of the injury Medical intervention Kinds of healing of wounds: a. Healing by primary intention -minimal tissue loss, more approximation of edges -without significant bacterial contamination. -within 24 hours there is acute neutrophilic response & scab formation -after 3 days macrophages and fibroblast activities in the epithelial layer, collagen bridge the raw area & newly formed capillaries will proliferate these to cover the exposed area -after a month complete return to normal state with or without scar formation. b. Healing by secondary intention c. Aberrated Healing Process: 1. Formation of exuberant granulation 2. Keloid formation 3. Stricture 4. Fistula or sinus formation 5