Tenosynovitis Workup

Updated: Jan 06, 2021
  • Author: Christopher S Crowe, MD; Chief Editor: Harris Gellman, MD  more...
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Workup

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.

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Laboratory Studies

A complete blood count (CBC) with differential is appropriate when there is concern for systemic illness. Characteristics include the following:

  • 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
  • WBC count is generally not elevated in nonsuppurative conditions and in immunocompromised patients
  • 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.

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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.

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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:

  • Sterile fluid is common with gonococcal arthritis; cultures are negative in 50% of patients
  • Joint fluid glucose is usually normal.
  • WBC counts are usually below 50,000/μL
  • A Gram stain is positive in only 25% of patients
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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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