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ULY CLINIC
ULY CLINIC
25 Septemba 2025, 01:41:50
Kanavel’s sign
Kanavel’s sign refers to tenderness along the flexor tendon sheath of a finger, typically the little finger, indicating flexor tenosynovitis (infectious inflammation of the tendon sheath). It is an important early clinical marker of this potentially serious hand infection.
Pathophysiology
Flexor tenosynovitis is usually caused by bacterial infection, most commonly Staphylococcus aureus.
Infection leads to inflammation, edema, and increased pressure within the tendon sheath.
This results in pain along the tendon, impaired movement, and potential risk of tendon necrosis or spread of infection if untreated.
Examination Technique
Patient positioning: Have the patient seated with the hand relaxed on a flat surface.
Inspection: Look for swelling, redness, or fusiform enlargement of the affected finger.
Palpation: Apply gentle but firm pressure along the flexor tendon sheath, starting at the palm and moving toward the finger.
Assessment: Pain localized along the tendon sheath, particularly proximal to the metacarpophalangeal (MCP) joint of the little finger, indicates a positive Kanavel’s sign.
Documentation: Note location, intensity of tenderness, and presence of swelling or erythema.
Clinical Features
Feature | Manifestation |
Tenderness | Along flexor tendon sheath, usually little finger |
Swelling | Fusiform (sausage-shaped) swelling of the finger |
Pain | Exquisite tenderness on palpation of the tendon sheath |
Function | Pain with passive extension of the finger; reduced active flexion |
Skin changes | Erythema, warmth over affected area |
Differential Diagnosis
Condition | Key Feature | Notes |
Flexor tenosynovitis | Painful, tender flexor tendon sheath | Usually acute, often bacterial |
Paronychia | Tenderness at the nail fold | Localized around the nail, not along the tendon |
Cellulitis | Diffuse swelling, erythema | Involves skin and subcutaneous tissue rather than tendon sheath |
Arthritis / Gout | Joint-centered pain and swelling | Pain localized to MCP, PIP, or DIP joints rather than entire tendon sheath |
Pediatric considerations
Rare in children; if present, often post-traumatic or due to hematogenous spread.
Tenderness may be difficult to elicit; observe for reluctance to move the finger.
Geriatric considerations
Older adults may have comorbidities (e.g., diabetes) increasing risk of rapid progression or poor healing.
Early recognition is crucial to prevent tendon damage.
Limitations
Pain may be difficult to localize in patients with altered sensation.
Not all tender flexor tendons indicate infection; must correlate with erythema, swelling, and history of trauma or puncture.
Definitive diagnosis may require ultrasound or MRI if clinical suspicion is high.
Patient counseling
Explain that the tenderness indicates possible infection along the tendon sheath.
Emphasize urgent evaluation and treatment (antibiotics ± surgical drainage) to prevent tendon necrosis.
Advise immobilization and careful monitoring for fever, spreading redness, or worsening pain.
Conclusion
Kanavel’s sign is an early and important indicator of flexor tenosynovitis, particularly in the little finger. Prompt recognition and management can prevent serious complications, including tendon rupture and systemic infection.
References
Kanavel AB. Inflammation of the Tendon Sheaths of the Fingers. JAMA. 1912;59:161–164.
Sharma S, et al. Flexor Tenosynovitis: Diagnosis and Management. Orthop Clin North Am. 2013;44(4):479–485.
Pang HN, Chong AK. Pyogenic Flexor Tenosynovitis: Current Concepts in Management. Hand (NY). 2011;6(1):1–7.
Wong JY, et al. Hand Infections in Adults: Clinical Features and Management. Surg Clin North Am. 2015;95(5):1025–1040.