A cadaveric study comparing the three approaches for ulnar nerve block at wrist

Area of Science:

• Anatomy
• Surgical Procedures
• Nerve Blocks

Background:

• Ulnar nerve blockade is crucial for hand surgery anesthesia.
• Anatomical variations necessitate improved blockade techniques.
• The flexor carpi ulnaris (FCU) muscle influences ulnar nerve location.

Purpose of the Study:

• Compare three ulnar nerve block techniques at the wrist: volar, transtendinous volar (TTV), and ulnar.
• Evaluate safety and efficacy in cadaveric models.
• Identify optimal technique for anesthesia and analgesia.

Main Methods:

• Study involved 40 human cadaver wrists.
• Standard hypodermic needles were used for three block techniques.
• Detailed dissection of FCU followed needle insertion.
• Measured needle tip distance to ulnar artery/nerve and incidence of piercing.

Main Results:

• Significant differences in mean needle tip distances to ulnar artery and nerve across techniques (P = 0.001).
• Volar approach had higher rates of inadvertent intra-arterial (35%) and intraneural (40%) injections.
• TTV and ulnar approaches showed statistically lower rates of complications.

Conclusions:

• The transtendinous volar (TTV) approach is recommended for ulnar nerve blockade at the wrist.
• TTV offers ease of practice, a safer profile, and fewer risks of inadvertent injections.
• This technique ensures adequate anesthesia and analgesia for hand procedures.