Summary
Infectious tenosynovitis is a closed infection within a tendon sheath that most commonly affects the joints of the hands. Causes include contiguous spread from adjacent structures, hematogenous spread, and direct infection from a puncture wound (e.g., human or animal bite, thorn prick injury). Gram-positive skin flora, specifically Streptococcus species and Staphylococcus species, are the most commonly involved pathogens, followed by gram-negative and anaerobic organisms. Clinical features of infectious tenosynovitis include swelling, pain, and erythema of the area around the involved tendon. In patients with hand involvement, presence of Kanavel signs on examination suggests infectious tenosynovitis. Diagnosis is based on clinical features and patient history. Laboratory tests and imaging can help confirm the diagnosis and assess severity. Infectious tenosynovitis is a medical emergency; therefore, management involves rapid identification and treatment with broad-spectrum IV antibiotics, hospital admission, and possible surgical intervention.
See also “Noninfectious tenosynovitis.”
Etiology
Microbial invasion of the tendon sheath [1]
- Contiguous spread of infection from adjacent structures
-
Direct infection from puncture wounds, e.g.,
- Human or animal bites
- Thorn prick injuries [2][3]
- IV drug use
- Hematogenous spread of infection
Pathogens [1][4]
-
Gram-positive organisms (most common)
- Streptococcus species
- Staphylococcus species including MRSA
-
Gram-negative and anaerobic organisms
- Eikenella corrodens
- Pseudomonas aeruginosa
- Pasteurella multocida (specific to cat bites)
- Neisseria gonorrhoeae: in disseminated gonococcal infections (DGI)
-
Other
- Mycobacterium species
- Fungi (e.g., Sporothrix schenckii)
Clinical features
Infectious tenosynovitis most commonly presents in the joints of the hand. [5][6]
Symptoms [4][7]
Examination findings
-
Kanavel signs: In patients with finger involvement, the presence of one or more signs suggests infectious tenosynovitis (i.e., pyogenic flexor tenosynovitis). [1][7]
- Holding the affected finger in a flexed position at rest
- Tenderness to palpation along the tendon sheath
- Pain with passive extension of the affected finger
- Fusiform swelling (> 95% of affected individuals) [7]
-
Other findings: May be present based on underlying etiology
- Clinical features of disseminated gonococcal infection (DGI)
- Signs of wound infection
- Signs of extensor tendon damage in individuals with dorsal hand injuries (e.g., positive Elson test) [1]
The absence of one or more Kanavel signs does not exclude the diagnosis of pyogenic flexor tenosynovitis. [7]
Kanavel signs are sometimes less apparent in children or when the thumb or pinky are affected. [7]
Diagnosis
Infectious tenosynovitis is a clinical diagnosis. Diagnostic studies may be obtained to confirm the diagnosis, identify the causative organism, and determine the extent of infection. [1][9]
- Laboratory studies: may show signs of infection, e.g., [7][10]
-
Microbiological studies
- Blood culture: for suspected hematogenous spread
- Diagnostics for DGI, if suspected
- Culture of open wounds
- Synovial culture or biopsy may be necessary for definitive diagnosis. [6]
-
Imaging [5][6]
- MRI (preferred): findings include tendon inflammation, effusion, and/or synovial thickening [5][6]
- X-ray: can identify bony involvement or foreign bodies
- Other imaging (e.g. CT scan or ultrasound) may be also obtained depending on suspected underlying etiology.
Treatment
Approach [1][4][7]
- Initiate broad-spectrum IV antibiotics and admit to the hospital.
-
Provide supportive care as needed.
- Wound management
- Tetanus prophylaxis, if indicated
- Splinting and elevation of the affected region
- Consult surgery immediately for [1]
- Advanced infection, e.g., ≥ 3 Kanavel signs, abnormal neurovascular exam, clinical features of acute compartment syndrome [4][11]
- No improvement 12–24 hours after initiation of IV antibiotics [1]
Antibiotic therapy [1][4]
- Initiate empiric broad-spectrum IV antibiotics based on clinical presentation and suspected organisms.
- All patients: Include coverage for gram-positive organisms (including MRSA), e.g.,vancomycin. [12]
- IVDU or immunocompromised: Add coverage for gram-negative and anaerobic organisms (e.g., piperacillin/tazobactam ). [12]
- Human or animal bites: See “Antibiotics for bite wounds.”
- Risk factors for Pseudomonas infection: Add an antipseudomonal antibiotic (e.g., meropenem ) [12][13]
- Suspected DGI: Add ceftriaxone (see also “Treatment of DGI”). [14]
- Tailor antibiotic therapy to culture results, if available. [4]
- For patients with mycobacterial or fungal infections: Consult infectious disease.
Initiate antibiotic treatment as soon as possible to decrease the likelihood of serious complications. [1]
Surgery [4][15]
- Incision with closed sheath catheter irrigation
- Open irrigation and debridement of necrotic and/or infected tissue
- Amputation may be required in severe cases. [11][16]
Occupational therapy is recommended after surgery. [1]
Complications
- Osteomyelitis
- Tendon necrosis and/or disruption
- Stenosing tenosynovitis
We list the most important complications. The selection is not exhaustive.