PHTLS Musculoskeletal Trauma 4 — Questions and Answers
Question 1: Which mechanism of injury is MOST likely to produce a posterior hip dislocation?
- A lateral impact to the pelvis
- A fall from height landing on the feet
- A dashboard impact with the knee in a flexed position (Correct answer)
- A direct blow to the greater trochanter
Correct answer: A dashboard impact with the knee in a flexed position
A dashboard injury where the knee strikes the dashboard while the hip is flexed transmits force posteriorly, forcing the femoral head out of the acetabulum posteriorly.
Question 2: What is the primary reason to check neurovascular status distal to a fracture BEFORE and AFTER splinting?
- To document pre-existing injuries for legal purposes
- To detect vascular or nerve compromise caused by or worsened by the splint (Correct answer)
- To determine if the patient requires surgical reduction
- To identify the exact fracture type before transport
Correct answer: To detect vascular or nerve compromise caused by or worsened by the splint
Neurovascular checks before and after splinting detect compromise present at injury and identify new compromise inadvertently caused by the splint.
Question 3: A patient has a mid-shaft humerus fracture after a fall. Which nerve is MOST commonly injured with this fracture and what deficit would you expect?
- Ulnar nerve; inability to abduct the thumb
- Median nerve; loss of palmar sensation in the index finger
- Radial nerve; wrist drop and inability to extend the fingers (Correct answer)
- Musculocutaneous nerve; loss of elbow flexion strength
Correct answer: Radial nerve; wrist drop and inability to extend the fingers
The radial nerve courses in the spiral groove of the humerus and is frequently injured with mid-shaft humeral fractures, resulting in wrist drop.
Question 4: A patient in hemorrhagic shock has a suspected pelvic fracture and open femur fracture. Which sequence of interventions is MOST appropriate?
- Traction splint first, then pelvic binder, then IV access
- Pelvic binder first, control femur hemorrhage, then traction splint during transport (Correct answer)
- IV access, then pelvic binder, then traction splint before moving patient
- Traction splint and pelvic binder simultaneously, then IV en route
Correct answer: Pelvic binder first, control femur hemorrhage, then traction splint during transport
In a multiply injured patient, hemorrhage control takes priority; the pelvic binder stabilizes the largest source of internal hemorrhage, then visible external femur bleeding is controlled before traction splinting.
Question 5: Which of the following BEST describes an open fracture classification concern in the prehospital setting?
- Formally classify the Gustilo-Anderson grade before splinting
- Identify any wound communicating with the fracture and treat as contaminated (Correct answer)
- Only treat wounds larger than 1 cm as open fractures
- Determine whether the bone end is still visible before covering the wound
Correct answer: Identify any wound communicating with the fracture and treat as contaminated
Prehospital providers should identify any wound near a fracture as potentially communicating with the fracture, treat it as contaminated, and cover it with a moist sterile dressing.
Question 6: A patient with bilateral femur fractures cannot receive bilateral traction splints due to equipment limitations. What is the BEST alternative immobilization strategy?
- Use a long backboard with padding and secure both legs together
- Apply one traction splint to the more deformed limb and splint the other in place (Correct answer)
- Elevate both legs on a pillow and secure loosely
- Apply pneumatic splints to both legs and inflate to maximum pressure
Correct answer: Apply one traction splint to the more deformed limb and splint the other in place
If only one traction splint is available, it should be applied to the more severely injured limb, and the other leg immobilized with a rigid or padded splint.
Question 7: Which of the following clinical signs would MOST suggest fat embolism syndrome following a long bone fracture?
- Localized swelling and bruising over the fracture
- Petechiae on the upper chest and axillae, altered mental status, and hypoxia (Correct answer)
- Fever above 40°C and rigors within 1 hour of injury
- Crepitus and abnormal motion at the fracture site
Correct answer: Petechiae on the upper chest and axillae, altered mental status, and hypoxia
Fat embolism syndrome classically presents with the triad of petechiae (particularly on the upper chest/axillae), neurological deterioration, and hypoxia 24–72 hours after long bone fracture.
PHTLS Musculoskeletal Trauma 4
Which mechanism of injury is MOST likely to produce a posterior hip dislocation?