The correct answer is B. Femur.
Why B is correct (Femur):
A fracture of the femur, especially the proximal femur (hip region), commonly results in:
This occurs because:
Strong muscles (particularly the hip external rotators) pull on the fractured bone
The limb naturally falls into an externally rotated position
NREMT-aligned trauma guidance states:
“Femur fractures often present with shortening and external rotation of the leg.”
“Muscle spasms and bone displacement alter normal limb alignment.”
Why the other options are incorrect:
A. Pubis: Pelvic fractures may cause pain and instability but do not typically cause isolated external rotation of the leg.
C. Patella: Affects the knee; does not cause external rotation of the entire leg.
D. L5 vertebra: Spinal injury; may cause neurologic deficits but not limb rotation.
Exact Extracts:
“Femur fractures commonly result in limb shortening and external rotation.”
“Muscle forces acting on the fractured femur alter positioning of the leg.”
“Assessment includes observing deformity and abnormal limb positioning.”
[References:, NREMT EMT Education Standards – Trauma (Musculoskeletal Injuries) , NREMT National Continued Competency Program (NCCP) – Trauma Emergencies , Prehospital Emergency Care (EMT) – Musculoskeletal Trauma , ==========================================, , , ]