Trauma Practice Questions

Q: A 50-year-old man sustained posterior dislocation of his left hip in an accident. The dislocation was reduced after 3 days. Six months later, he began complaining of pain in his left hip. X-rays of the pelvis were normal. What is the most relevant investigation at this stage?

MRI of the hip. **Explanation:** The clinical scenario describes a patient at high risk for **Avascular Necrosis (AVN) of the femoral head**. AVN is a common complication of posterior hip dislocation, especially when reduction is delayed (in this case, 3 days). The blood supply to the femoral head (primarily the medial circumflex femoral artery) is compromised during dislocation, leading to bone ischemia. **1. Why MRI is the correct answer:** The patient presents with hip pain six months post-injury, but X-rays are normal. This indicates **Stage I AVN** (Ficat and Arlet classification), where structural changes haven't yet appeared on plain radiographs. **MRI is the most sensitive and gold-standard investigation** for early diagnosis of AVN, as it can detect marrow edema and signal changes (the "double-line sign") long before bone collapse occurs. **2. Why other options are incorrect:** * **CRP levels:** These are markers of inflammation or infection (e.g., septic arthritis), which is less likely than AVN in a post-traumatic setting without systemic symptoms. * **Ultrasonography:** Useful for detecting joint effusions or soft tissue pathology but lacks the sensitivity to diagnose early intraosseous ischemia. * **Arthrography:** Primarily used to assess joint congruity or labral tears; it does not visualize the internal vascularity or health of the bone marrow. **Clinical Pearls for NEET-PG:** * **Golden Period:** Hip dislocations should ideally be reduced within **6 hours** to minimize the risk of AVN. * **Most common complication:** Osteoarthritis (long-term); AVN (early-to-mid term). * **X-ray findings in late AVN:** Sclerosis, "Crescent sign" (subchondral fracture), and femoral head collapse. * **Classification:** Ficat and Arlet is the most commonly asked classification for AVN in exams.

Q: What is a straddle fracture?

Pelvis fracture. ### Explanation **Correct Answer: C. Pelvis fracture** A **Straddle Fracture** is a specific type of pelvic ring injury characterized by **bilateral fractures of the superior and inferior pubic rami**. It is typically caused by a direct blow to the midline of the bony pelvis (e.g., falling astride a beam or a motorcycle accident). From a biomechanical perspective, it is considered an **unstable** injury because it results in a "floating" anterior segment of the pelvis. The most significant clinical concern in straddle fractures is the high incidence of associated **genitourinary injuries** (up to 20%), particularly ruptures of the posterior urethra or bladder. --- ### Why other options are incorrect: * **A. Shoulder fracture:** Shoulder injuries are classified by specific eponyms like Bankart or Hill-Sachs lesions, but "straddle" refers specifically to the pelvic anatomy. * **B. Wrist fracture:** Common wrist fractures include Colles’, Smith’s, or Barton’s fractures, which involve the distal radius. * **D. Ankle fracture:** Ankle fractures are usually classified by the Lauge-Hansen or Danis-Weber systems based on the mechanism of rotation and fibular involvement. --- ### NEET-PG High-Yield Pearls: * **Mechanism:** Direct vertical impact to the perineum. * **Key Association:** Always rule out **urethral injury** (look for blood at the meatus, high-riding prostate, or inability to void). * **Radiology:** X-ray shows four fractures (bilateral superior and inferior rami). * **Malgaigne Fracture:** Another high-yield pelvic fracture involving vertical shear (fracture through the pubic rami and ipsilateral SI joint/sacrum). * **Open Book Fracture:** Results from Antero-posterior compression (APC), leading to symphysis pubis diastasis.

Q: A 24-year-old woman fell while ice-skating. What abnormality is shown?

Posterior elbow dislocation. ***Posterior elbow dislocation*** - Most common elbow dislocation, typically caused by **fall on outstretched hand (FOOSH)** mechanism, which matches this ice-skating injury. - X-ray shows **disrupted radiocapitellar line** and **posterior displacement** of radius and ulna relative to the humerus. *Posterior shoulder dislocation* - Would show **lightbulb sign** on X-ray with **fixed internal rotation** of the humeral head. - Typically occurs from **seizures** or **electric shock**, not from FOOSH mechanism during ice-skating. *Fracture of radius* - Would show **clear cortical break** or **discontinuity** in the radial bone on X-ray. - **Colles' fracture** is more common with FOOSH, but shows fracture line rather than joint dislocation. *Fracture of ulna* - Would demonstrate **cortical disruption** or **fracture line** through the ulnar bone. - **Olecranon fractures** can occur with elbow trauma, but show bone fragmentation rather than joint displacement.

Q: Maximum shortening of limbs occurs in which condition?

Post-dislocation of the hip. **Explanation:** The degree of limb shortening in hip injuries depends on the extent of proximal migration of the femoral head or shaft relative to the acetabulum. **1. Why Posterior Dislocation of the Hip is Correct:** In a posterior dislocation, the femoral head is forced out of the acetabulum and driven superiorly and posteriorly onto the ilium. Because the head is completely displaced from its socket and rests significantly higher on the pelvic bone, it results in the **maximum clinical shortening** (typically 2–4 cm). This is classically associated with a "Dashboard injury" and presents with a limb that is **shortened, adducted, and internally rotated.** **2. Analysis of Incorrect Options:** * **Trochanteric Femur Fracture:** While shortening occurs due to the pull of the gluteal and hip flexor muscles, it is generally less than in a posterior dislocation because the capsule and some bony contact often limit the proximal migration. * **Femoral Neck Fracture:** Shortening is a feature (due to muscle spasm), but it is usually **minimal to moderate** (about 1–2 cm). The limb is typically abducted and externally rotated. * **Anterior Dislocation of the Hip:** This condition usually presents with a limb that appears **lengthened** (or of normal length) because the femoral head is displaced inferiorly and anteriorly (obturator type). The limb is classically abducted and externally rotated. **3. Clinical Pearls for NEET-PG:** * **Posterior Dislocation:** Shortened + Adducted + Internally Rotated (Mnemonic: **S**hort **A**nd **I**n). * **Neck of Femur Fracture:** Shortened + Abducted + Externally Rotated (Mnemonic: **S**hort **A**nd **E**x). * **Nerve Injury:** Posterior dislocation is most commonly associated with **Sciatic nerve** palsy (specifically the peroneal component). * **Emergency:** Hip dislocations are orthopedic emergencies due to the high risk of **Avascular Necrosis (AVN)** of the femoral head.

Q: In a 70-year-old lady with an intracapsular fracture of the neck of femur, what is the ideal treatment?

Hemiarthroplasty. **Explanation:** The management of intracapsular femoral neck fractures is primarily determined by the **patient's age** and the **degree of displacement**. **Why Hemiarthroplasty is the correct choice:** In an elderly patient (70 years old), the primary concerns are the high risk of **Avascular Necrosis (AVN)** of the femoral head and **non-union**, due to the precarious retrograde blood supply (mainly the medial circumflex femoral artery). At this age, the goal is early mobilization to prevent complications of prolonged bed rest (like DVT or pneumonia). Hemiarthroplasty allows for immediate weight-bearing and avoids the high failure rates associated with internal fixation in osteoporotic bone. **Analysis of Incorrect Options:** * **A. Closed traction:** This is a temporary measures for pain relief or stabilization. It is never a definitive treatment for neck of femur fractures as it leads to malunion and complications of recumbency. * **C & D. Internal Fixation (Nail/Plate):** While internal fixation (e.g., Cannulated Cancellous Screws) is the treatment of choice for **young patients** (<60 years) to "save the head," it is avoided in the elderly due to poor bone quality and the high risk of re-operation if AVN develops. **High-Yield Clinical Pearls for NEET-PG:** 1. **Garden’s Classification:** Used for displacement. Garden I & II (undisplaced) may be treated with screws; Garden III & IV (displaced) in elderly require arthroplasty. 2. **Hemiarthroplasty vs. Total Hip Arthroplasty (THA):** If the patient is 70 and active/fit, **THA** is increasingly preferred over hemiarthroplasty to provide better long-term functional outcomes. However, in standard MCQ scenarios, Hemiarthroplasty remains the classic answer for the elderly. 3. **Pauwels’ Classification:** Based on the angle of the fracture line; higher angles (Type III) are more unstable and prone to non-union.

Q: Which is the most frequently dislocated joint in the body?

Glenohumeral joint. **Explanation:** The **Glenohumeral (shoulder) joint** is the most frequently dislocated joint in the body due to its unique anatomical trade-off: it sacrifices stability for an extraordinary range of motion. **Why it is the correct answer:** The instability of the glenohumeral joint arises from three primary factors: 1. **Disproportionate Articular Surfaces:** The large humeral head is roughly four times the size of the shallow glenoid cavity (often compared to a "golf ball on a tee"). 2. **Lax Capsule:** The joint capsule is thin and loose to allow for wide-ranging movements. 3. **Dependence on Soft Tissue:** Stability relies heavily on the rotator cuff muscles and the glenoid labrum rather than bony congruence. **Analysis of Incorrect Options:** * **Acromioclavicular joint:** While common in athletes (often called "shoulder separation"), it is less frequent than glenohumeral dislocation. * **Ankle joint:** This is a highly stable hinge joint supported by strong ligaments (medial/lateral). Injuries here are more commonly fractures or sprains rather than complete dislocations. * **Hip joint:** As a deep "ball and socket" joint with strong bony congruence and powerful ligaments (like the Iliofemoral ligament), it requires massive force (e.g., dashboard injuries) to dislocate. **High-Yield Clinical Pearls for NEET-PG:** * **Direction:** **Anterior dislocation** is the most common type (approx. 95%). * **Nerve Injury:** The **Axillary nerve** is the most commonly injured nerve in shoulder dislocations (check for "regimental badge" anesthesia). * **Associated Lesions:** Look for **Bankart’s lesion** (detachment of the anteroinferior labrum) and **Hill-Sachs lesion** (compression fracture of the posterolateral humeral head). * **Least Stable Position:** The joint is most vulnerable in **abduction and external rotation**.

Q: Meyer's procedure is a method for treatment of which of the following conditions?

Fracture neck of femur. **Explanation:** **Meyer’s procedure** is a muscle-pedicle bone grafting technique used specifically for the treatment of **Fracture Neck of Femur**. The primary challenge in femoral neck fractures is the precarious blood supply to the femoral head, which often leads to non-union or Avascular Necrosis (AVN). In this procedure, a piece of bone (usually from the posterior femoral neck or greater trochanter) is harvested along with its attachment to the **Quadratus femoris muscle**. This vascularized bone graft is then fixed across the fracture site to provide both mechanical stability and a continuous blood supply to promote healing. **Analysis of Incorrect Options:** * **Recurrent shoulder dislocation:** Common procedures include the **Bankart repair** (soft tissue) or the **Latarjet procedure** (coracoid process transfer). * **Habitual dislocation of patella:** Surgical options include the **Roux-Goldthwait procedure** (distal realignment) or the **Campbell’s procedure**. * **Congenital dislocation of hip (DDH):** Management involves the **Pemberton osteotomy**, **Salter’s osteotomy**, or **Pavlík harness** (non-surgical), depending on the age of the patient. **High-Yield Clinical Pearls for NEET-PG:** * **Muscle involved in Meyer’s:** Quadratus femoris (provides the vascular pedicle). * **Indications:** Usually reserved for young patients with displaced femoral neck fractures or cases of non-union where head preservation is desired. * **Other Bone Grafts in Orthopaedics:** * **Phemister Graft:** Onlay bone graft for non-union. * **Fibula Graft:** Often used for large segmental defects or AVN of the femoral head.

Question 1

A 50-year-old man sustained posterior dislocation of his left hip in an accident. The dislocation was reduced after 3 days. Six months later, he began complaining of pain in his left hip. X-rays of the pelvis were normal. What is the most relevant investigation at this stage?

Accepted Answer

MRI of the hip

Answer

CRP levels in blood

Answer

Ultrasonography of the hip

Answer

Arthrography of the hip

Question 2

What is a straddle fracture?

Accepted Answer

Pelvis fracture

Answer

Shoulder fracture

Answer

Wrist fracture

Answer

Ankle fracture

Question 3

Which of the following is a true statement regarding posterior dislocation of the shoulder joint?

Accepted Answer

Internal rotation

Answer

External rotation

Answer

Axillary nerve palsy

Answer

Anterior hollowness

Question 4

A 24-year-old woman fell while ice-skating. What abnormality is shown?

Accepted Answer

Posterior elbow dislocation

Answer

Posterior shoulder dislocation

Answer

Fracture of radius

Answer

Fracture of ulna

Question 5

Maximum shortening of limbs occurs in which condition?

Accepted Answer

Post-dislocation of the hip

Answer

Trochanteric femur fracture

Answer

Femoral neck fracture

Answer

Anterior dislocation of the hip

Question 6

In a 70-year-old lady with an intracapsular fracture of the neck of femur, what is the ideal treatment?

Accepted Answer

Hemiarthroplasty

Answer

Closed traction

Answer

Internal fixation with nail

Answer

Internal fixation with nail and plate

Question 7

Which is the most frequently dislocated joint in the body?

Accepted Answer

Glenohumeral joint

Answer

Acromioclavicular joint

Answer

Ankle joint

Answer

Hip joint

Question 8

Which of the following statements is not true regarding traction?

Accepted Answer

K-wires (Kirschner wires) are commonly used to facilitate skeletal traction.

Answer

Skeletal traction is generally preferred over skin traction for femur fractures due to better stability and reduced risk of complications.

Answer

The maximum weight that can typically be applied in skeletal traction is around 25% of the patient's body weight.

Answer

Skin traction is often preferred for pediatric patients due to ease of application and reduced invasiveness.

Question 9

Meyer's procedure is a method for treatment of which of the following conditions?

Accepted Answer

Fracture neck of femur

Answer

Recurrent shoulder dislocation

Answer

Habitual dislocation of patella

Answer

Congenital dislocation of hip

Question 10

A 5-year-old boy presents with a fracture in the shaft of the humerus. How will you exclude the involvement of the radial nerve?

Accepted Answer

Inability in extension of the wrist and loss of sensation in the area over the anatomical snuff box.

Answer

Inability in flexion of the forearm and loss of sensation in the lateral forearm.

Answer

Inability to flex the metacarpophalangeal joint and extend the proximal interphalangeal joint.

Answer

Inability to perform opposition.

Trauma — MCQs

Trauma — MCQs

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