Injury of extensor tendon should be examined according to different parts and different reasons. If it is suspected that it is secondary to diseases such as distal radius fracture or wrist synovitis, the primary disease should be diagnosed by X-ray plain film or CT and magnetic resonance imaging. If it is the injury of extensor tendon, it is necessary to take a lateral plain film of the affected finger to judge whether there is an avulsion fracture.
The diagnosis of extensor tendon injury itself mainly depends on clinical examination. Of course, some extensor tendon injuries can also be diagnosed by B-ultrasound, and some extensor tendon injuries can also be diagnosed by magnetic resonance imaging. However, if the injury site is relatively far away, its diagnostic specificity is not too high.