Carpal Tunnel Injections: A Novel Approach Based on Wrist Width.
BACKGROUND
Carpal tunnel steroid injections (CTIs) have the potential risk of damaging underlying critical structures, including the median nerve (MN), radial artery (RA), and ulnar neurovascular bundle (UB). The purpose of this study was to analyze the safety of a volar radial (VR) and volar ulnar (VU) CTI, using standardized anatomical "safe zones."


METHODS
This study was performed on 87 cadaveric arms using a percentage of the total wrist width as a guide for placement of a VR (30 and 33% of total wrist width) and VU (60 and 66% of total wrist width) injection.


RESULTS
Our results demonstrate a wide range of anatomic variations in the location of these critical neurovascular structures near the carpal canal, indicating that using superficial landmarks alone for CTIs may result in an increased risk of iatrogenic injury to these critical structures.


CONCLUSIONS
We propose a technique using a percentage of total wrist width as a guide for CTIs. Both VR (30% of wrist width) and VU (60% of wrist width) CTIs offer relatively safe and reliable CTI locations to the carpal canal.


METHODS
Not applicable/cadaveric study.
The Steadman Clinic, Vail, Colorado, United States.
Travis J
TJ
Menge
Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States.
Elizabeth B
EB
Rinker
VICC Cancer Biostatistics Center, Nashville, Tennessee, United States.
Kang-Hsien
KH
Fan
Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Medical Center North, Tennessee, United States.
John J
JJ
Block
Vanderbilt University Medical Center, Vanderbilt Orthopaedic Institute, Nashville, Tennessee, United States.
Donald H
DH
Lee
anatomic location; carpal tunnel; safety; steroid injection