Final answer:
Cutting-point tip spinal needles increase the risk of dural puncture but are designed to be less traumatic to tissues. A lumbar puncture, used to diagnose conditions like meningitis, is safely performed in the lower lumbar region to withdraw CSF and avoid the risk of damaging the spinal cord.
Step-by-step explanation:
Cutting-point tip spinal needles are designed to increase the risk of dural puncture but are less traumatic to tissues compared to standard needles. These needles have a specific design that includes a side opening to allow the cerebrospinal fluid (CSF) to enter the needle without requiring the tip to significantly puncture or damage the dura mater. This design aims to reduce the potential for post-dural puncture headaches and other complications associated with a larger-gauge needle creating a significant dural puncture.
The spinal cord does not extend through the lower lumbar region, so it is safer to introduce a needle in this area for a lumbar puncture without risking damage to the central nervous tissue. The lumbar puncture is usually performed between the third and fourth lumbar vertebrae, where there is ample space to insert the needle and access the CSF. This procedure is helpful in diagnosing conditions such as meningitis, which can be caused by various pathogens.