Abstract: Objective To evaluate the accuracy of ultrasonographic diagnosis for central slip rupture of the finger extensor tendon mechanism of the proximal interphalangeal joint.Methods Sixty-seven consecutive patients with injuries to the proximal interphalangeal joint underwent ultrasonic examination with a linear 5-10 MHz hockey stick-shaped scanner head. Meanwhile three methods of physical examination were applied to assess the injury, and the results of ultrasonic detection and physical examinations were compared with surgical findings.Results Thirty-nine patients with central slip rupture of the finger extensor mechanism were confirmed. Ultrasonography achieved good consistence with surgical findings in injury detection. For ultrasound and physical examinations, the sensitivity for injury detection was 100% and 89.74% with specificity of 96.43% and 82.14%, respectively, showing significant difference (P<0.01).Conclusion As an accurate noninvasive method, ultrasonographic diagnosis can identify central slip rupture in the extensor mechanism of the finger over the proximal interphalangeal joint in early stages.