Abstract
Blockade of the suprascapular nerve (SSN) with local anaesthetic is used frequently in shoulder surgery and for chronic shoulder pain. Anatomical landmarks may be used to locate the nerve prior to infiltration with local anaesthetic, but ultrasound is becoming a popular to locate the nerve.
Twelve cadaveric shoulders from 6 specimens were injected with dye using the landmark and ultrasound technique. The shoulders were scanned with computed tomography, and then dissected to ascertain the accuracy of each technique.
Using CT scan results, we found the ultrasound group to be more accurate in placing the anaesthetic needle close to the suprascapular notch, and therefore nerve, and this was significant (p = 0.0009). When analysing the ink data, although we did not observe a significant difference in amount of nerve covered by ink, we did note a correlation, and, given this study group is small, that may be considered a statistical trend.
This study, which is one of the largest cadaveric studies investigating landmark and ultrasound guided block of the suprascapular nerve and we believe the first to use CT, demonstrates that ultrasound guided block is significantly more accurate than the landmark technique, and would therefore recommend that ultrasound guidance be used when blocking the suprascapular nerve, given its higher accuracy and lower complication rate.
