Tendon sheath infection, particularly in the hand, is a serious condition that requires prompt medical attention. Recognizing its key indicators, often referred to as Kanavel's cardinal signs, is crucial for timely diagnosis and treatment. These four distinct signs are widely recognized in medical practice for identifying flexor tendon sheath infections.
Here are the four cardinal signs that indicate a possible tendon sheath infection:
| Sign of Infection | Description |
|---|---|
| 1. Finger Held in Slight Flexion | The affected finger will naturally rest in a slightly bent or curved position, rather than being fully extended or relaxed. This posture is often adopted to minimize pain. |
| 2. Fusiform Swelling | There will be noticeable, spindle-shaped swelling directly over the affected finger, encompassing the entire digit from base to tip. The swelling typically appears more pronounced on the palm side. |
| 3. Tenderness Along the Flexor Tendon Sheath | Pressure applied directly along the path of the flexor tendon sheath on the palm side of the finger will elicit significant pain. This tenderness usually extends from the palm towards the fingertip. |
| 4. Pain with Passive Extension | Even gentle attempts to straighten or extend the affected finger passively (by someone else or using the other hand) will cause severe pain, as this motion stretches the inflamed tendon sheath. |
Why Recognizing These Signs Matters
Early recognition of these signs is vital because tendon sheath infections can progress rapidly and lead to severe complications, including:
- Tendon necrosis: Death of the tendon tissue.
- Adhesions: Scar tissue that limits finger movement.
- Joint stiffness: Permanent loss of range of motion in the affected digit.
- Spread of infection: The infection can extend to other parts of the hand or even become systemic, leading to broader health issues.
If you suspect a tendon sheath infection based on these signs, it is imperative to seek immediate medical evaluation. Prompt diagnosis and treatment, often involving antibiotics and sometimes surgical intervention, are essential to prevent permanent damage and preserve hand function.
For more information on conditions affecting tendons and hands, you can refer to reputable medical resources such as the American Academy of Orthopaedic Surgeons (AAOS).
