Scan in two planes, and compare to the contralateral side if needed. Because of anisotropy, be sure to hold the probe perpendicular to the tendon in order to avoid mistaking tendon for fluid.
False negatives can occur with ultrasound in early PFT when fluid accumulation is minimal, so clinical suspicion based on all information gathered should guide clinical management.
Once PFT is suspected, it is important to initiate empiric antibiotic therapy—commonly vancomycin and/or piperacillin/tazobactam—to improve clinical outcomes (14). Elevate the hand to reduce swelling. Definitive treatment, however, is surgical incision and drainage, so early consultation of a hand specialist is also necessary. Cultures can be obtained in the OR and antibiotic therapy narrowed once speciation and sensitivities are determined.
Although success with non-surgical treatment has been described, no studies have evaluated outcomes for PFT with antibiotics alone, and further investigation is warranted (14).
The patient was started on vancomycin, and orthopedics was consulted. She was taken to the OR for an emergent incision and drainage that was notable for the release of frank pus from the index finger flexor sheath as well as murky fluid in the palm. Piperacillin/tazobactam was added, and the patient showed gradual improvement in erythema, swelling, and range of motion throughout her hospital course. Speciation and sensitivities revealed methicillin-sensitive Staphylococcus aureus (MSSA), and antibiotics were narrowed. The patient was transitioned to oral antibiotics and discharged on post-operative day #4 with orthopedic follow-up.
TAKE HOME POINTS
- Pyogenic flexor tenosynovitis can result in significant morbidity and is a surgical emergency.
- Kanavel’s signs are used to diagnose PFT, but remember that the absence of Kanavel’s signs does not exclude early PFT:
- Fusiform swelling.
- Finger held in flexion.
- Pain with passive extension.
- Tenderness along the flexor tendon sheath.
- Point-of-care ultrasound is a helpful tool in distinguishing PFT from other causes such as cellulitis or abscess.
- Consider using the water-bath technique to image the hand.
- Look for hypoechoic or anechoic fluid within the tendon sheath or thickened tendons.
- If PFT is suspected, start broad-spectrum empiric antibiotics, splint and elevate the hand, and consult a hand specialist for possible operative management.
Faculty Reviewer: Dr. Jeff Feden
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