Flexor tenosynovitis is a clinical diagnosis.
Cardinal signs of this condition are described as “Kanavel’s Signs,” as described by Dr. Allen Kanavel in 1912
1. Exquisite tenderness over the flexor tendon
2. Finger held in flexion at rest
3. Exquisite pain upon passive extension of the finger
4. Fusiform swelling of the finger2
Literature noting the individual sensitivity and specificity of each Kanavel sign is sparse. A descriptive analysis provided by Pang et al observed 75 patients with flexor tenosynovitis and noted the presence of fusiform swelling to be the most common (97%), followed by pain on passive extension (72%), flexed finger at rest (69%), and pain along the flexor sheath (65%)4.