BACKGROUND: Volar plating is the preferred surgical treatment for distal radius fractures. Many have adopted unicortical distal fixation to prevent extensor tendon injury. This study aimed to determine the biomechanical effect of distal locking screws and pegs on stability in comminuted, intra-articular distal radius fracture cadavers. METHODS: We applied volar-locking distal radius plates to 24 cadaveric radiuses, which were divided into 4 groups based on distal fixation: 100 % length screws, 75 % length screws, 100 % length pegs, and 75 % length pegs. Osteotomies simulated dorsally comminuted, intra-articular fractures. We determined each construct's stiffness under physiologic loads (axial compression, dorsal bending, and volar bending) before and after 1000 cycles of axial conditioning, and before axial load to clinical failure (2 mm of displacement) and catastrophic failure. FINDINGS: Stiffness to volar and dorsal bending were equivalent between groups before and after cycling loading. Final stiffness under axial load was equivalent for all groups. Force to clinical failure was equivalent between 100 % (308 N) and 75 % screw length (351 N) constructs, and equivalent between 100 % (127 N) and 75 % peg length (150 N) constructs. Forces to clinical failure were greater for 100 % and 75 % screw lengths compared to their peg counterparts. Force to clinical failure was greater for 75 % screw lengths than 100 % smooth pegs. Force to catastrophic failure was equivalent between all groups. INTERPRETATION: We recommend the use of 75 % length screws or pegs over their bicortical counterparts to prevent dorsal penetration without compromising fixation. Surgeons may consider using locking screws over pegs in complex, intra-articular distal radius fractures.