**Question:** Complication of neck femur fracture are all except

A. Orthostatic hypotension
B. Cardiac arrest
C. Pulmonary embolism
D. Acute kidney injury

**Core Concept:** Femur fractures are severe injuries that can lead to complications, particularly in the elderly population due to osteoporosis and deconditioning. Commonly encountered complications include cardiovascular, respiratory, and renal sequelae.

**Why the Correct Answer is Right:** The correct answer, "Cardiac arrest," is not a complication of neck femur fracture as cardiac arrest is a life-threatening event caused by severe cardiac dysfunction or ischemia, unrelated to a femur fracture.

**Why Each Wrong Option is Incorrect:**

A. Orthostatic hypotension (postural hypotension) is a decrease in blood pressure upon standing, which can be exacerbated by femur fractures due to reduced blood volume, decreased cardiac output, and redistribution of blood flow. This is a potential complication related to the femur fracture.

B. Pulmonary embolism is a serious complication that can occur after femur fractures due to the immobility, increased risk of deep vein thrombosis, and potential damage to the deep veins of the lower limbs. Although not directly related to neck femur fracture, it is a complication of lower limb trauma.

C. Acute kidney injury (AKI) is a concern following femur fractures due to the stress response, blood loss, and reduced blood flow to the kidneys. It is a complication associated with femur fractures.

D. Acute kidney injury is a complication related to femur fractures, as mentioned above. Though not directly related to neck femur fracture, it is a potential complication of any femur fracture.

**Clinical Pearl:** Femur fractures, particularly neck femur fractures, carry a significant risk of complications. Healthcare professionals should be vigilant for these complications, monitor patients' vital signs, and manage them appropriately to minimize morbidity and mortality.