Approach Considerations
Pyogenic flexor tenosynovitis (PFT) represents an orthopedic emergency; tenosynovitis from other causes can undergo a less urgent workup. All patients with suspected flexor tenosynovitis should be transferred to a center capable of specialty evaluation and should be evaluated upon presentation to the emergency department (ED). For patients whose presentations are unclear or who are thought to have early infection, judicious use of nonsurgical management can be initiated and repeat evaluation performed in 6-12 hours.
Laboratory Studies
A complete blood count (CBC) with differential is appropriate when there is concern for systemic illness. Characteristics include the following:
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White blood cell (WBC) count is generally within the normal range for isolated hand infections, though it may be elevated in the presence of progessive infection or systemic involvement
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WBC count is generally not elevated in nonsuppurative conditions and in immunocompromised patients
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Left shift is frequently observed in acute processes
The erythrocyte sedimentation rate (ESR) and the C-reactive protein (CRP) level are nonspecific inflammatory markers that may be obtained and followed to determine response to treatment. These will also frequently be normal in closed-space infections of the hand.
Creatinine will provide information about renal function, which may have an impact on antibiotic selection.
Coagulation studies are needed in anticoagulated patients or in patients with a known or suspected bleeding diathesis. In severe infections where systemic sepsis is a concern, disseminated intravascular coagulation (DIC), though quite rare, must be ruled out.
Rheumatoid factor (RF) should be tested for if rheumatoid arthritis (RA) is a consideration.
If the patient is febrile or has any degree of vital instability, blood cultures should be drawn and sent before antibiotic therapy is initiated.
Gonococcal cultures of the urethra or cervix, rectum, and pharynx are appropriate if gonococcal tenosynovitis is suspected. One of these cultures is positive in approximately 80% of patients. In addition, transiently elevated liver function studies (LFTs) have been described with disseminated gonococcal infection.
Imaging Studies
Standard anteroposterior and lateral radiographs should be obtained to rule out bony involvement (eg, osteomyelitis, arthritis, or unrecognized trauma) or a foreign body. [43]
Magnetic resonance imaging (MRI) has proved accurate in assisting in the diagnosis of tenosynovitis. [44] It is expensive and generally unnecessary, in that the diagnosis is usually clinically evident.
Aspiration and Evaluation of Joint Fluid
Aspiration of synovial fluid will allow microbiologic and histopathologic analysis of the fluid. Culture and gram stain should ideally be obtained before the initiation of definitive antibiotic therapy and typically includes aerobic, anaerobic, fungal, acid-fast bacilli (AFB), and atypical AFB samples. Histopathologic analysis of synovial fluid may show nonbirefringent crystals (gout) or birefringent crystals (calcium pyrophosphate disease [CPPD; pseudogout]).
Diagnostic arthrocentesis is indicated when joint effusion is present with tenosynovitis because most patients with disseminated gonococcal infection have coexistent septic arthritis. (Most gonococcal arthritis is monoarticular; ~25% of cases are polyarticular.) Characteristics of the aspirated fluid can include the following:
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Sterile fluid is common with gonococcal arthritis; cultures are negative in 50% of patients
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Joint fluid glucose is usually normal.
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WBC counts are usually below 50,000/μL
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A Gram stain is positive in only 25% of patients
Histologic Findings
Histopathologic examination of synovial biopsy specimens is helpful in diagnosing granulomatous changes observed in Mycobacterium infections and in cases of chronic processes.
Synovial biopsy may reveal acute or chronic inflammatory changes. These histologic findings help to confirm a diagnosis of inflammatory arthropathy. [45] Gram stains may reveal bacteria. A higher index of suspicion should be present for chronic infections or atypical presentations.
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Flexor tendon sheaths and radial and ulnar bursae.
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Location of anular and cruciform pulleys.
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First dorsal compartment of wrist includes tendon sheath that encloses abductor pollicis longus and extensor pollicis brevis tendons at lateral border of anatomic snuffbox.
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Eichoff test is performed by having patient make fist with thumb inside fingers. Clinician then applies ulnar deviation of wrist to reproduce presenting symptoms of dorsolateral wrist pain.
Tables
| Stage I | Early inflammation of the tendon sheath and accumulation of exudative fluid |
| Stage II | Continued inflammation of the tendon sheath and distention with purulent fluid |
| Stage III | Necrosis of the tendon and tendon sheath, possible tendon rupture |
Infection Stage |
Characteristic Findings |
Treatment |
I |
Increased fluid in sheath, mainly serous exudate |
Catheter irrigation |
II |
Purulent fluid, granulomatous synovium |
Minimal invasive drainage ± indwelling catheter irrigation |
III |
Necrosis of tendon, pulleys, or tendon sheath |
Extensive open débridement and possible amputation |
