Sharp Force Injuries — MCQs
What is the characteristic of a lacerated wound over a bony surface due to blunt trauma without excessive skin crushing?
Which of the following is a characteristic feature specifically seen in contact gunshot wounds?
Which of the following statements about exit wounds of a bullet in bone is correct?
In an incised wound, all of the following are true, except:
A dead body is found to have marks like branching of a tree on the front of the chest. The most likely cause of death could be due to:
False among the following
A polytrauma patient's CT brain shows a crescent-shaped extra-axial collection with a concave inner margin. What is the most likely diagnosis?
Identify the condition shown in the given X-ray:
Waste Sharps should be disposed in ?
A baby was vigorously shaken by parents. What do you expect in the baby?
Sharp Force Injuries Indian Medical PG Practice Questions and MCQs
Question 1: What is the characteristic of a lacerated wound over a bony surface due to blunt trauma without excessive skin crushing?
- A. Flaying
- B. Regular sharp margins (Correct Answer)
- C. Irregular margins
- D. Tearing
Explanation: ***Regular sharp margins*** - A **lacerated wound** on a bony surface from **blunt trauma** without significant crushing often has margins that appear regular and sharp due to the skin tearing over the underlying bone. - The **tensile strength** of the skin leads to a clean tear rather than an irregular rip when stretched over a hard surface. *Irregular margins* - **Irregular margins** are typically found in lacerations caused by a glancing or tearing force, or when there is significant **crushing** of the tissue. - This results in a more jagged and uneven wound edge due to varied tissue resistance. *Tearing* - While a laceration is a form of tearing, simply stating "tearing" doesn't sufficiently describe the **morphology of the wound margins** when occurring over a bony surface. - The term "tearing" is broad and does not emphasize the specific characteristic of the wound edges in this particular scenario. *Flaying* - **Flaying** refers to the severe separation of a large section of skin and subcutaneous tissue from the underlying fascia and muscle. - This is a more extensive injury than a simple laceration and typically involves a significant shearing force that lifts the skin.
Question 2: Which of the following is a characteristic feature specifically seen in contact gunshot wounds?
- A. Stellate shaped wound is seen in contact shot (Correct Answer)
- B. Harrison-Gilroy test can detect gunshot residue
- C. Entry wound is beveled in the inner table of skull
- D. Abrasion collar is seen in entry wound
Explanation: ***Stellate shaped wound is seen in contact shot*** - A **stellate (star-shaped) wound** pattern is characteristic of a contact gunshot wound due to the **gases from the firearm expanding rapidly** under the skin upon entry, causing the skin to tear in an irregular, star-like fashion. - This occurs when the muzzle of the weapon is pressed firmly against the skin, allowing the hot gases to be injected into the tissue. *Harrison-Gilroy test can detect gunshot residue* - The Harrison-Gilroy test is an outdated method for detecting **gunshot residue (GSR)**, primarily looking for **lead, barium, and antimony**. - While it can detect GSR, it is not specific to contact wounds and can be positive with other ranges of fire; more modern analytical techniques like **scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX)** are more reliable for GSR detection. *Entry wound is beveled in the inner table of skull* - The **inner table beveling** (also known as a **Gubler's bevel**) is characteristic of an **exit wound** from a projectile passing through the skull. - An **entry wound** in the skull typically shows **outer table beveling**, as the projectile punches through the outer bone before entering the inner, softer bone. *Abrasion collar is seen in entry wound* - An **abrasion collar**, also known as a **contusion collar** or **scuff mark**, is a characteristic feature around an **entry gunshot wound** where the bullet rubs against the skin as it penetrates. - It's present in most entry wounds, regardless of contact or distant range, but is not *specific* to contact wounds as the stellate shape is.
Question 3: Which of the following statements about exit wounds of a bullet in bone is correct?
- A. Abrasion collar
- B. Smaller than entry wound
- C. Presence of COHb
- D. Bevelled (Correct Answer)
Explanation: ***Bevelled*** - Beveling (internal beveling) is the **characteristic feature** of exit wounds in bone, particularly in skull fractures - The exit wound shows a **cone-shaped defect** with the **wider opening on the exit side** and the narrow end toward the entry side - This "coning effect" occurs because bone fragments are **pushed outward** as the bullet exits, creating a larger, more irregular defect - **Definitive forensic finding** for distinguishing entry from exit wounds in bone *Smaller than entry wound* - This is **incorrect** for bone wounds - Exit wounds in bone are typically **larger and more irregular** than entry wounds, not smaller - The entry wound in bone appears as a small, punched-in defect with **external beveling** (narrow on outside, wider on inside) - Exit wounds are larger due to the bullet's tumbling and fragmentation, plus outward force creating the beveling *Abrasion collar* - An **abrasion collar** (marginal abrasion) is characteristic of **entry wounds in skin**, not bone - Occurs when skin is pressed inward and abraded by the bullet at entry - **Not present** around exit wounds because skin is pushed outward, causing irregular tearing - This feature applies to soft tissue, not bone wound characteristics *Presence of COHb* - **Carboxyhemoglobin (COHb)** indicates a **close-range gunshot entry wound** - Results from carbon monoxide in gunpowder gases deposited in the wound tract - Associated with **entry wounds only**, particularly at close range or contact wounds - Not relevant to exit wound characteristics
Question 4: In an incised wound, all of the following are true, except:
- A. Tailing is often present
- B. It has clean-cut margins
- C. Bleeding is generally less than in lacerations (Correct Answer)
- D. Length of injury does not correspond with length of blade
Explanation: ***Bleeding is generally less than in lacerations*** - Incised wounds, due to their **clean-cut nature** and often transected blood vessels, typically result in **more profuse external bleeding** compared to lacerations. - Lacerations often have torn vessels and crushed tissue, which can promote **hemostasis** to some degree, leading to less external bleeding than deep incised wounds. *Tailing is often present* - **Tailing** refers to the superficial beginning and ending of an incised wound, appearing as a shallow scratch. - This feature is characteristic of incised wounds created by a **sharp object drawn across the skin**. *It has clean-cut margins* - Incised wounds are caused by **sharp-edged instruments** that slice through tissue, resulting in margins that are smooth, sharp, and without significant tissue damage. - The absence of crushing or tearing around the wound edges is a hallmark of an incised wound. *Length of injury does not correspond with length of blade* - The length of an incised wound can often be **longer than the width of the blade** (e.g., a small knife producing a long wound) or **shorter than the blade's full length** if only a part of the blade comes into contact with the skin. - This lack of direct correlation is important for forensic analysis in determining the nature of the weapon.
Question 5: A dead body is found to have marks like branching of a tree on the front of the chest. The most likely cause of death could be due to:
- A. Lightning injury (Correct Answer)
- B. Road traffic accident
- C. Injuries due to bomb blast
- D. Firearm
Explanation: ***Lightning injury*** - The branching, tree-like marks described are known as **Lichtenberg figures**, which are characteristic cutaneous patterns caused by the passage of high-voltage electrical current, such as during a **lightning strike**. - These transient patterns are believed to be due to dilation of capillaries or arborizing superficial burns, sometimes referred to as ferning. *Road traffic accident* - Injuries from a **road traffic accident** typically include blunt force trauma, lacerations, fractures, and internal organ damage, but they do not produce branching, tree-like skin marks. - The pattern of injury is usually widespread and indicative of impact, shearing, or crushing forces, which is distinct from the described branching marks. *Injuries due to bomb blast* - **Bomb blast injuries** are usually categorized as primary (blast wave), secondary (projectiles), tertiary (body displacement), and quaternary (miscellaneous, e.g., burns, toxic inhalation). They would not typically produce the specific Lichtenberg figures. - While burns can occur, they are usually thermal or chemical burns, not the characteristic superficial dendritic branching marks seen with lightning. *Firearm* - **Firearm injuries** result from projectiles (bullets), leading to entrance wounds, exit wounds (if applicable), and internal organ damage along the bullet's path. - The markings associated with firearms do not include branching, tree-like patterns on the skin; instead, they might show tattooing, stippling, or muzzle imprint with close-range shots.
Question 6: False among the following
- A. Teardrop fracture involves C5-C6 vertebrae
- B. Hangman fracture involves Axis
- C. Clay Shoveler's fracture involves C6 vertebrae (Correct Answer)
- D. Jefferson's fracture involves Atlas
Explanation: ***Clay Shoveler's fracture involves C6 vertebrae*** - A **Clay Shoveler's fracture** typically involves the **spinous processes of C6, C7 or T1**, meaning C6 is often involved. - This fracture is usually stable and results from forced neck flexion or direct trauma, often affecting lower cervical or upper thoracic vertebrae. *Teardrop fracture involves C5-C6 vertebrae* - **Teardrop fractures** are severe and unstable fractures of the cervical spine, often occurring at **C2 or C5-C7 (not exclusively C5-C6)**. - They are named for the characteristic triangular fragment of bone detached from the anterior aspect of the vertebral body and can be either flexion or extension type, with flexion teardrop fractures being particularly unstable due to posterior ligamentous disruption. *Hangman fracture involves Axis* - A **Hangman's fracture** is a fracture of the **C2 (Axis) pedicles**, typically due to hyperextension and distraction. - While it involves C2, the statement implies it solely involves the "Axis" which is broad, but specifically it's the pedicles of C2. *Jefferson's fracture involves Atlas* - A **Jefferson's fracture** is a burst fracture of the **C1 (Atlas) ring**, typically caused by an axial load on the head. - This fracture involves the Atlas, as stated, and is often unstable due to disruption of the transverse atlantal ligament in severe cases.
Question 7: A polytrauma patient's CT brain shows a crescent-shaped extra-axial collection with a concave inner margin. What is the most likely diagnosis?
- A. EDH
- B. SDH (Correct Answer)
- C. Contusion
- D. Diffuse axonal injury
Explanation: ***SDH*** - The image shows a **crescent-shaped collection** of hemorrhage with a concave inner margin, consistent with a **subdural hematoma** (SDH). - SDHs result from the tearing of **bridging veins** and typically conform to the brain's surface, crossing suture lines but not limited by bony sutures. *EDH* - An **epidural hematoma (EDH)** characteristically appears as a **lenticular** or **biconvex** shape on CT, not crescent-shaped. - EDHs are typically caused by arterial bleeding, often from the **middle meningeal artery**, and are limited by cranial sutures. *Contusion* - A **contusion** is brain tissue bruising that appears as **heterogeneous areas** of hemorrhage and edema within the brain parenchyma itself. - It would not manifest as a distinct extra-axial collection with a smooth, concave margin. *Diffuse axonal injury* - **Diffuse axonal injury (DAI)** involves widespread microscopic damage to axons, often at the gray-white matter junction. - It may appear as *punctate hemorrhages* or **small lesions** at these junctions on CT, but often the CT can be normal, and it would not present as a large extra-axial collection.
Question 8: Identify the condition shown in the given X-ray:
- A. Tibial tuberosity fracture
- B. Osgood-Schlatter disease (Correct Answer)
- C. Gerdy's tubercle fracture
- D. Lateral epicondyle of femur
Explanation: ***Correct Answer: Osgood-Schlatter disease*** - The X-ray shows characteristic **fragmentation** and **irregularity** of the **tibial tuberosity**, which is pathognomonic for Osgood-Schlatter disease. - This condition commonly affects **adolescents** during periods of rapid growth, causing **anterior knee pain** that worsens with activity. - The radiographic findings demonstrate chronic **traction apophysitis** at the insertion of the **patellar tendon**. *Incorrect: Tibial tuberosity fracture* - An acute tibial tuberosity fracture would show a **distinct fracture line** with possible displacement, rather than the chronic fragmentation pattern seen here. - This type of fracture typically results from **sudden forceful quadriceps contraction** and presents with acute onset of severe pain. *Incorrect: Gerdy's tubercle fracture* - Gerdy's tubercle is located on the **lateral aspect of the proximal tibia**, serving as the insertion point for the **iliotibial band**. - A fracture at this location would not explain the **anterior tibial tuberosity changes** visible in this X-ray image. *Incorrect: Lateral epicondyle of femur* - The lateral epicondyle of the femur is located at the **distal end of the femur**, not at the tibial tuberosity where the radiographic changes are visible. - Pathology at the lateral epicondyle would not cause the **tibial tuberosity fragmentation** seen in this X-ray.
Question 9: Waste Sharps should be disposed in ?
- A. Black bag
- B. Yellow bag (Correct Answer)
- C. None of the options
- D. Blue bag
Explanation: ***Yellow bag (Historical answer per BMW Rules 1998)*** - Under the **Biomedical Waste Management Rules 1998** (applicable at the time of NEET-PG 2015), **sharps waste** including needles, syringes, and scalpels were disposed in **yellow puncture-proof containers**. - This was the correct answer when this question was asked in the 2015 examination. - **Current Guidelines (BMW Rules 2016):** Sharps are now disposed in **white/translucent puncture-proof containers**, NOT yellow bags. Yellow bags are currently used for soiled infectious waste like dressings and body fluid-contaminated materials. *Black bag* - **Black bags** are used for **general non-hazardous waste** that poses no biological risk. - Disposing of sharps in black bags creates serious **risk of needlestick injuries** and potential transmission of bloodborne pathogens. *None of the options* - This is incorrect because there is a specific, regulated method for disposing of sharps in healthcare settings. - Proper waste segregation is **mandatory** for safety and regulatory compliance. *Blue bag* - **Blue bags** (per BMW Rules 2016) are used for disposal of **glassware** (broken or discarded) and **metallic body implants**. - Under older guidelines, blue bags were for certain pharmaceutical waste. - They are not designated for sharps disposal.
Question 10: A baby was vigorously shaken by parents. What do you expect in the baby?
- A. Ruptured spleen
- B. Rib fractures
- C. Sub-dural hematoma (Correct Answer)
- D. Pelvic fracture
Explanation: ***Sub-dural hematoma*** - **Shaken baby syndrome** results from violent shaking, leading to rapid acceleration and deceleration that causes tearing of the **bridging veins** in the brain. - This tearing results in a **subdural hematoma**, which is a collection of blood between the dura mater and arachnoid mater. *Ruptured spleen* - While possible in severe trauma, a ruptured spleen is less common with shaking alone and more often associated with **direct abdominal impact**. - The mechanisms of injury for splenic rupture typically involve significant blunt force to the abdomen, which is not the primary injury in shaken baby syndrome. *Rib fractures* - Rib fractures are indicators of significant chest compression or **direct impact**, which can occur in child abuse but are not the primary, immediate effect of shaking a baby. - While rib fractures can be a component of child abuse, they typically result from a different type of forceful interaction than shaking. *Pelvic fracture* - Pelvic fractures in infants typically require **high-energy trauma**, such as a fall from a significant height or a motor vehicle accident. - They are highly unlikely to result from shaking alone, as the pelvis is not directly impacted during a typical shaking event.
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