These needles all come in different sizes - for orthopedic purposes we mainly use 22G and 25G needles

However - if you are struggling with a difficult spinal - upgrading to a 22G Quincke cutting needle to complete the procedure is worth the small increase in risk for PDPH in order to avoid a failed spinal/patient/surgeon/self disatisfaction. This is my personal opinion - feel free to disagree 🤓

First of all - why do we care? One of the dreaded complications of neuraxial anesthesia is the post-dural puncture headache (PDPH). Several procedural risk factors have been identified including needle type (cutting vs pencil point), and needle gauge. Things that increase procedural success (cutting, larger gauge) are also thought to increase risk of PDPH - so it is up to us to find the right balance in our orthopedic joints population. 

A brief discussion of pros and cons

Gauge

• Smaller gauge needles are thought to reduce incidence of post-dural puncture headache (when studied in OB patients) but provide little tactile feedback to the user and are difficult to pass through tough tissue/ligament. CSF flow and aspiration are much slower and difficult to appreciate in some patients

• Larger gauge needles may increase the incidence of headache (when studied in OB patients) but are superior tools for accessing the subarachnoid space, and provide easier CSF flow and aspiration confirmation of correct placement

Needle Tip

• Pencil point needles are thought to reduce the incidence of post-dural puncture headaches (when studied in OB patients). These needles are not sharp enough to penetrate the skin and thus need an introducer needle to go through. Repositioning the introducer for each pass of the needle takes time

• Cutting needles are thought to increase the risk of post-dural puncture headache (when studied in OB patients). Since they are sharp they can be used without an introducer which saves time and allows for multiple passes.