Fixation of unstable distal radius fractures with palmar locking plates provides a stable reduction and early return of function, but complications arising from unrecognized dorsally prominent screws penetrating the extensor compartments are increasingly reported. Standard radiographs and fluoroscopy may not adequately visualize screw lengths, owing to the complex shape of the dorsum of the distal radius. We examined 46 distal radius fractures treated with palmar locking plates by ultrasound. Of the total 230 locking screws, 59 protruded from the dorsal cortical surface by 0.5 mm or more (range 0.5-6.1 mm). The first extensor compartment was violated by one screw, the second compartment by 22 screws, the third compartment by 15 screws, and the fourth compartment by 21 screws. Asymptomatic tenosynovitis was detected in four and symptomatic tenosynovitis in 14 of the 59 prominent screws. Ultrasound imaging may be useful in cases where intra-articular and/or comminuted fractures require distal plate placement and engagement of screws in the dorsal cortex.