Contrast Enhanced Computed Tomography in the Diagnosis of Acute Pyogenic Flexor Tenosynovitis

Abstract

Background: The diagnosis of infectious flexor tenosynovitis (FTS) has historically been made based on physical exam using Kanavel’s signs. The specificity of these findings has come into question. We looked to evaluate the use of contrast-enhanced computed tomography (CT) in increasing the successful diagnosis of FTS. Methods: Two adult cohorts were formed, one of patients with FTS confirmed in the operating room and the second of patients with ICD.10 identified finger cellulitis (FC), without concomitant FTS. Demographics, laboratory values, CT scans, and examination findings were evaluated. Axial CTs were evaluated in the coronal and sagittal planes and tendon sheath/tendon width were measured. The tendon sheath/tendon was recorded as a ratio in the coronal (CR) and sagittal (SR) planes. Continuous and dichotomous variables were analyzed and measures of sensitivity, specificity, and predictivity were calculated. Seventy patients were included, 35 in the FTS cohort and 35 with FC. Result: A higher number of Kanavel signs were present in the FTS group (2.9 vs. 0.5, P < .05), with CR and SR both being significantly larger in the FTS group ( P < .05). CR and SR cutoffs ≥ 1.3 provided high sensitivity, specificity, and positive predictive value (PPV) for FTS. Likelihood of FTS increased 5.9% and 5.5% for every 0.1 increase in CR and SR, respectively, with a 14% increase for every additional Kanavel sign. Conclusion: In conclusion, CT ratios are useful in identifying FTS; and when used on their own or in combination with Kanavel’s signs, CR and SR objectively improve the diagnosis of FTS.

Infectious Extensor Tenosynovitis of the Hallucis Longus Tendon: A Case Report

“…Infectious tenosynovitis often results from trauma with direct inoculation of bacteria spreading from local tissues or blood. Flexor tenosynovitis is most common and recognized by its characteristic swelling of the affected digit, Kanavel signs, which demonstrate tenderness along the flexor sheath, and pain with passive extension [ 3 ]. Extensor tenosynovitis is a less common diagnosis usually seen in the wrist or ankle [ 4 ].…”

“…Clinical suspicion is paramount to obtaining appropriate imaging such as magnetic resonance imaging (MRI) and emergent orthopedic consultation for management. Contrast computerized tomography (CT) or ultrasound (US) have lower sensitivity but can be used where MRI is not available [ 3 , 6 ]. Prompt treatment with broad-spectrum antibiotics and orthopedic consultation is essential to prevent complications such as decreased function, tendon sheath rupture, osteomyelitis, necrotizing fasciitis, and amputation [ 7 ].…”