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Updated: Aug 17, 2026

Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies
Published on: January 11, 2019
[Phlegmon of the digital and digital-carpal synovial sheaths]
1SOS Mains Boucicaut service d'orthopédie-traumatologie et chirurgie réparatrice hôpital Boucicaut, Paris.
Abstract:
The development of infection within the digital synovial sheaths of the middle fingers, or digital-carpal sheaths of the thumb and the little finger, represents a surgical emergency. Due more often to direct infection than to its spread, such phlegmons risk damage to the finger flexor apparatus, within hours in the first case and within days in the second. Diagnosis is made clinically. It is based on pain at the upper cul-de-sac of the sheath, distinct from that of the causal point. Progression consists of three stages according to presence and quantity of pus in the sheath, the appearance of the synovial membrane and tendon involvement. This diagnosis can be made only at surgery. Each stage requires specific treatment.
Insights
Infection of digital synovial sheaths is a surgical emergency. Prompt clinical diagnosis and surgical intervention are crucial to prevent damage to the finger flexor apparatus.
Area of Science:
- Hand surgery
- Infectious diseases
- Orthopedics
Background:
- Infection of digital synovial sheaths, including digital-carpal sheaths of the thumb and little finger, constitutes a surgical emergency.
- Phlegmons in these sheaths, often from direct infection, pose a significant risk of damage to the finger flexor apparatus.
Purpose of the Study:
- To outline the clinical diagnosis and staging of synovial sheath infections.
- To emphasize the surgical emergency and specific treatment requirements for each stage.
Main Methods:
- Clinical diagnosis based on characteristic pain at the sheath's upper cul-de-sac.
- Surgical evaluation to determine the stage of infection based on pus presence, synovial membrane appearance, and tendon involvement.
Main Results:
- Diagnosis is primarily clinical, with definitive staging confirmed during surgery.
- Three distinct stages of infection progression are identified, correlating with pus accumulation and tissue damage.
Conclusions:
- Early recognition and surgical intervention are critical for managing digital synovial sheath infections.
- Tailored surgical treatment based on the identified stage is essential to preserve flexor apparatus function.
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