1. Etiology
Spinal cord blade injuries are mostly caused by crime, with the victim suffering an attack from behind. The most common weapon is a knife, followed by an axe, and there are also screwdrivers, bicycle spokes, sickles, and sharpened bamboo or wooden sticks, etc. After the injury, the blade can be immediately removed, or it may remain or partially break within the body.
1、The pathways by which the blade punctures the spinal cord
()1)Through the interspinous space: This is the most common. The spinous process of the vertebrae protrudes posteriorly, and the transverse process protrudes laterally and posteriorly, forming a longitudinal groove between them. It is easy for the blade to enter the interspinous space or slide up and down behind the vertebral plate, then enter this space. Therefore, nearly half of spinal cord blade injuries are hemisectional injuries.
()2)Through the intervertebral foramen: The vast majority of blades entering between the vertebrae are long and sharp, which can cause injury to the spinal cord, nerve roots, and blood vessels.
()3)Through the vertebral plate: By using force, a sharp blade is inserted into the vertebral plate, causing injury to the blade itself and the fractured fragments of the vertebral plate, thereby injuring the spinal cord.
2、The ways spinal cord injury occurs are divided into two types
()1)Direct injury: The blade or bone fragment directly pierces the spinal cord, nerve root, or blood vessel.
()2)Concussive injury: The blade enters one side of the vertebral canal, pushing the spinal cord to the opposite side, causing an impact injury on the opposite side.
2. Pathogenesis
The simple spinal blade injury rarely causes death, often does not require surgical exploration, therefore, the early pathological data is scarce. Autopsies of those who died from associated injuries can show that part or all of the spinal cord has been removed, or it may only be contused, with the断面swelling and inversion, the dura may be damaged, and there may be a hematoma within the vertebral canal. In cases of injured radicular arteries, the spinal cord may necrose and soften. The sharper the weapon, the greater the possibility of vascular injury.