THE PALMAR LOCKING COMPRESSION PLATE IS BIOMECHANICALLY COMPARABLE TO THE DORSAL PI PLATE FOR DORSALLY COMMINUTED, INTRAARTICULAR WRIST FRACTURES

A clinically appropriate fracture model and testing regimen were used to test the null hypothesis that a palmarly applied locking plate was inferior to a dorsally applied Pi plate in the stabilisation of dorsally comminuted intraarticular wrist fractures. Sixteen standardised fractures of Synbone models of the radius were stabilised using either a palmar locking compression T plate (the experimental group) (n=8) or a dorsally applied Pi plate (the control group) (n=8). The constructs were tested on an Instron materials testing machine. Deformation was monitored during 500 loading cycles to 200 N. The mean permanent deformation and stiffness favoured the palmar locking compression T plate over the dorsal Pi plate (P=0.036). However, the absolute difference was only 0.5 mm. Such a small difference is unlikely to be clinically detectable and, therefore, we conclude that there is no clinically significant difference between the two types of fixation.