Case: A 51-year-old woman, with no pertinent past medical history, presented to the Emergency Department (ED) complaining of right hand pain after a large fragment from a wooden cooking spoon penetrated her right palm approximately 1 week ago. She reported immediately removing the splinter and starting old, previously prescribed amoxicillin prior to her visit. She was prompted to visit the ED after her pain gradually increased, affecting her ability to flex and extend her right fourth digit.
On physical exam, the patient was afebrile with all other vital signs within normal limits. There was significant tenderness localized to the base of the right fourth digit near the proximal interphalangeal (PIP) joint, associated with edema, ecchymosis, and erythema. While the patient’s right hand remained neurovascularly intact, significant restrictions in passive motion, including flexion and extension, was noted to the right fourth digit. On visual inspection, no foreign bodies were appreciated.
A radiograph of the right hand was ordered, which was negative for any acute abnormalities, including foreign body. However, due to the patient’s clinical presentation and the potential radiolucency of the suspected foreign body, a point-of-care ultrasound was performed.
Background
Soft tissue injuries are a common presentation. While retained foreign bodies are not that common, missed ones are a common cause of malpractice claims (Halaas 2007)
Diagnostic dilemma for practitioners
Traditional approaches (plain radiography, computed tomography) do not always identify foreign bodies (Ginsburg 1990)
Traditional techniques come at the expense of radiation and increased throughput times
Radiolucent objects such as wood or plastic are often not visualized
Ultrasonography presents several advantages over traditional imaging techniques for the identification and localization of foreign bodies
Highly reliable modality for detecting non-radiopaque foreign bodies
High frequency linear transducer (7.5-10 MHZ) is placed on the area of interest
Area of interest is then scanned in both sagittal and transverse planes in search of the hyperechoic object
Tegaderm may be placed over a laceration to avoid further contamination of the wound site
Standoff pad may be used to elevate the transducer: fill a glove with ultrasound gel to help identify very superficial foreign bodies
Alternative technique is placing the extremity in a water bath with the probe placed just below the surface of the water, but does not need to contact the skin as the water acts as an ultrasound medium to enhance visualization
Case Findings
Figure 1: Linear hyperechoic structure located directly above the flexor tendon in sagittal view. Findings consistent with a foreign body
Identify object and critical surrounding structures
Hold u/s probe in long axis
Introduce retrieval device and use u/s guidance to obtain foreign body
Slowly remove foreign body in the same direction it was introduced – AVOID damaging nearby critical structures
Confirm retrieval of ENTIRE foreign body
Case Conclusion
Ultrasound findings were shared with orthopedic surgery, who recommended antibiotic therapy and outpatient foreign body removal. Subsequently, the patient was prescribed cephalexin, given strict return precautions, and instructed to follow up at the orthopedic clinic.
Figure 8: Successful foreign body removal with retraction to the skin surface
Take Home Points
Foreign bodies present a diagnostic dilemma for practitioners
Wood and plastic are often not identified on traditional imaging
Ultrasonography presents several advantages over traditional imaging techniques for the identification and localization of foreign bodies
Rapid diagnostic modality
Assist with removal in real time
Guest Post By:
Ellsworth Wright, MD MBS Brandon Somwaru, DO
PGY-2
St. Joseph’s Regional Medical Center
Paterson, NJ
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Ginsburg M et al. Detection of Soft-Tissue Foreign Bodies by Plain Raidography, Xerography, Computed Tonography, and Ultrasonography. Ann Emerg Med. 1990. PMID: 2188542
Halaas GW. Management of foreign bodies in the skin. Am Fam Physician. 2007. PMID: 17894138
Lyon M et al. Detection of Soft Tissue Foreign Bodies in the Presence of Soft Tissue Gas. J Ultrasound Med 2004. PMID: 15154535
Pattamapaspong N. et al. Accuracy of radiography, computed tomography and magnetic resonance imaging in diagnosing foreign bodies in the foot. Radiol Med. 2013. PMID: 22744349
Paziana K et al. Soft tissue foreign body removal technique using portable ultrasonography. Wilderness Environ Med. 2012. PMID: 22835803
Geria R. Ultrasound Guided Procedures: Foreign Body Localization. Sonoguide 2008. [Link is HERE]
Post Peer Reviewed By: Anand Swaminathan, MD (Twitter: @EMSwami)
