Pyogenic flexor tenosynovitis

In patients with pyogenic flexor tenosynovitis, four classic signs are described (Kanavel signs) including fusiform swelling of the whole finger, partially flexed posture of the finger, tenderness limited to the course of the flexor tendon sheath, and disproportionate pain on passive extension of the finger. The photographs illustrate the fusiform swelling of the finger and the partially flexed posture of the finger.