How Close Are the Volar Wrist Ligaments to the Distal Edge of the Pronator Quadratus? An Anatomical Study.

Background: This cadaveric study defines the interval distance between the proximal insertion of the volar wrist ligaments and the distal edge of the pronator quadratus on the distal radius. It is important to be aware of this distance during surgical dissection for placement of volar locking plates for wrist fractures. Disruption of the volar wrist ligament insertion may have adverse biomechanical consequences such as carpal instability, which can lead to pain and eventually wrist arthritis. Methods: Thirteen cadaveric wrists were dissected using the trans-flexor carpi radialis volar approach to identify relevant anatomy. The distance between the distal border of the pronator quadratus and the most proximal insertion of the volar wrist ligaments was measured. Results: The average distance between the pronator quadratus and the proximal insertion of the volar wrist ligaments was 5 mm, with a standard deviation of 2 mm. Conclusions: The volar wrist ligaments insert quite near the distal end of the pronator quadratus. Surgeons should be cognizant of the proximity of the volar wrist ligaments and be judicious with subperiosteal stripping of the distal fragment during volar plating procedures.