The commonest cause of paraplegia is-
**Core Concept**
Traumatic paraplegia is a form of spinal cord injury that results in the loss of motor and sensory function below the level of the injury. The common causes of traumatic paraplegia are motor vehicle accidents, falls from a height, and penetrating injuries such as gunshot wounds.
**Why the Correct Answer is Right**
The correct answer is spinal cord compression due to vertebral fracture, which is the most common cause of traumatic paraplegia. This can occur when a vertebral body is fractured or dislocated, leading to compression of the spinal cord and subsequent loss of function. The mechanism of injury typically involves a sudden and forceful flexion or extension of the spine, which can cause the vertebral bodies to fracture or dislocate. The resulting compression of the spinal cord can lead to a range of symptoms, including paralysis, sensory loss, and autonomic dysfunction.
**Why Each Wrong Option is Incorrect**
* **Option A:** Spinal cord ischemia is a less common cause of paraplegia, typically occurring in the setting of aortic aneurysm or dissection. It is not the most common cause of traumatic paraplegia.
* **Option B:** Spinal stenosis is a degenerative condition that can cause compression of the spinal cord, but it is not typically associated with traumatic injury and is not the most common cause of paraplegia.
* **Option C:** Spinal cord tumors are a rare cause of paraplegia and are not typically associated with traumatic injury.
**Clinical Pearl / High-Yield Fact**
The American Spinal Injury Association (ASIA) classification system is used to assess the severity of spinal cord injury, with patients classified as ASIA A (complete injury) to ASIA E (no motor function below the level of injury).
**Correct Answer:** C.