January Case #1: Painful Forearm- Discussion

This patient has a forearm psuedoaneurysm of an interosseous artery. He underwent a CTA of the right forearm which shows nonvisualization of the ulnar artery within the proximal forearm. The CTA was unable to fully evaluate the pseudoaneursym (possible due to its size- there was a small blush of contrast within the region. This was thought to represent artifact vs. hematoma vs. pseudoanuerysm).

The patient ultimately underwent angiography with embolization of the pseudoaneurysm. After successful embolization, the patient's radial artery was widely patent, but the ulnar artery teminates at the site of the pseudoaneysm. Ulnar artery filling was perserved only by retrograde filling through the palmar arch.

Pseudoaneurysm

Pseudoaneurysm or false aneurysm, is a tear in the arterial wall allowing blood to leak from the vessel into the surrounding tissue. The resulting hematoma walls off the surrounding tissue, creating a cavity. Blood leaking from the artery then swirls within this cavity, creating the classic findings on ultrasound. It is a complication most commonly described after diagnostic cardiac catheterizaiton through the femoral artery. It is indeed a "false" aneursym, as the intimal layers of the arterial wall do not comprise the borders of the outpouching. On color flow doppler, you can clearly see blood swirling in the cavity. This is termed the "ying-yang" sign, which is blood swirling both toward the probe (seen in red) and away from the probe (in blue).
Note that the patent vessel deep to the pseudoaneurysm maintains its normal size and shape. Spectral doppler of the stalk of the psuedoanuerysm would demonstrate turbulent flow.

January Case #1: Painful Forearm

25 yo WM presents with increasing right forearm pain and swelling for the past 6 days. He is 5 weeks status post fasciotomy for stab wound to the R forearm and resultant compartment syndrome. Patient denies erythema, fever, chills, or odor/purulence of the incision sites. He does endorse chronic numbness of the right 2nd digit since the injury. The pain is “throbbing.” He is undergoing physical therapy, but has been gradually decreasing compliance with sessions secondary to the increasing pain.
PMHx: Anemia, secondary to blood loss
PSHx: R volar forearm fasciotomy 5 weeks ago
Meds: Percocet, Gabapentin
Allergies: NKDA
FHx: negative
Soc Hx: occasional ETOH, chews tobacco

PE:
Vitals: BP: 132/78, Pulse: 101, RR: 16, Temp: 98.8, Pox: 100%
GEN: A&O x 3, NAD
HEENT: NCAT
CV: RRR, no M/R/G, HR 92 now
RESP: CTA B
ABD: soft, NTND, +BS
EXT: 2+ radial pulses bilaterally, R forearm tight and significantly swollen. Granulation tissue present over fasciotomy sites. No evidence of erythema. No purulence. No axillary lymphadenopathy. Decreased light touch sensation to all fingers on R hand. Wrist held in flexion, with limited extension secondary to pain.

Bedside ultrasound of the right forearm shows:

January Case #1-1 from UF-Jax Emergency Medicine on Vimeo.


January Case #1-2 from UF-Jax Emergency Medicine on Vimeo.






January Case #1-3 from UF-Jax Emergency Medicine on Vimeo.

What’s the Diagnosis?

Thanks to special guest contributer, Dr. Murray Baker, for this case! Excellant job!

December Case #3 Discussion

This patient has evidence of necrotizing fasciitis on ultrasound. He had plain films taken which illustrated gas in the tissues.

He was taken to the OR for debridement of the area and was noted to have purulent debris in both the volar and dorsal forearm compartments with resultant compartment syndrome. He had fasciotomies of both compartments and the excision of the purulent material. He subsequently underwent multiple debridements and eventually had a right shoulder disarticulation due to purulent material found throughout his forearm, elbow and biceps. His wound cultures grew out klebsiella and VRE.

Necrotizing Fasciitis

Necrotizing fasciitis (NF) is a rapidly spreading, progressive infection of the deep fascia with secondary necrosis of the subcutaneous tissues. Subcutaneous air is classically associated with NF due to gas forming organisms.

Cheng et al, noted that upper extremity NF has a higher mortality rate (35%). Mental status depression and respiratory distress on presentation were factors associated with higher mortality. Diabetes and other immunocompromised states are also risk factors.

On Ultrasound, NF appears to distort the facial layer, causing thickening of the subcutaneous tissue and muscle layer with hypoechoic fluid collections adjacent. Gas may also be visualized as a hyperechoic area with posterior shadowing (the hyperechoic area appears to fade into the shadow).




Cheng NC, Su YM, Kuo YS, Tai HC, Tang YB. Factors affecting the mortality of necrotizing fasciitis involving the upper extremtities. Surg Today. 2008;38(12):1108-13.

December Case #3

65 y/o AAM presents to the ED with complaints of elevated blood sugar and lethargy. Pt denies pain, SOB, N/V/D, or trauma.

PMHx: DM, HTN
PSHx: none

Meds: ASA, Norvasc, HCTZ, Lisinopril, Insulin

Allergies: NKDA

FamHx: none

SocHx: none

PE: BP 109/77, P 86, R 16, T 98.1, POx 96% (RA)

GEN: thin AAF, lethgargic

HEENT: PERR, dry MM, no JVD

CHEST: CTA B, nonlabored

CV: RRR, no M/R/G
ABD: soft, NTND, + BS

EXT: no C/C, + edema to R arm extending from wrist to mid humerus, min TTP, no ecchymosis or erythema, ROM difficult to assess secondary to lethargy

Bedside ultrasound of the RU Ext performed with the following findings:

What is the diagnosis?


Thanks to Dustin Brimblecom for submitting this case!

November case #2: Discussion

This patient appears to have a complete Achilles Tendon Rupture.

Normal Achilles Tendon Evaluation

The patient should be placed in a prone position so that you can easily reach the area of interest. The high frequency linear probe is placed in a longitudinal plane along the posterior ankle with the probe indicator toward the patient's head. The Achilles tendon may be visualized as a hyperechoic straited area (below pic). Moving from the proximal calf to the heel, the tendon may be followed to its insertion at the calcaneus.

Achilles Tendon Rupture

The Achilles Tendon attaches the soleus and gastrocenemius muscles to the calcaneus. Rupture is due to forceful plantar flexion. If there is a full thickness tear, as in this case, there will be a complete disruption of the tendon fibers with resultant retraction of the tendon proximally. This usually occurs about 3-4 cm proximal to the attachment to the calcaneus where there is a decreased vascularity. The ends of the ruptured tendon usually appear tapered and may cause some acoustic shadowing posteriorly (refraction). The space between the two tendon stumps may be filled with heterogeneous fluid, anechoic fluid (blood) or some of the adjacent fatty tissue (from Kager's fat pad).

It is important to evaluate the tendon in motion. This can be done by calf squeeze or by passive motion of the foot. This will make a tendon tear more obvious as one of the tendon stumps will move but the other will not.

Lastly, watch for an avulsion fracture of the calcaneus in Diabetic patients, which can mimic an Achilles tendon tear. The tendon itself will remain intact, but the portion of the calcaneous where the tendon attaches will be fractured off. This will be evident as you follow the tendon distally to the calcaneus.

November Case # 2

36 y/o male presents to ED with c/o pain to back of right lower leg. Pain began the day prior while playing basketball. Pain was a sudden onset while running and pt now unable to plantar flex his foot.


PMHx: none
PSHx: none
FamHx: none
Meds: none
Allergies: none
SocialHx: denies tobacco, ETOH or drugs


PE: BP 98/60, P83, R16, T98.6, POx 92% RA
GEN: NAD
EXT: no discoloration or bruising, mild edema to R calf w/ TTP, decreased ROM R foot- unable to plantar flex, sensation intact, 2+ distal pulses bilaterally. Thompson test +


What is your differential diagnosis?


Bedside ultrasound is used to evaluate the injury, what does the following image indicate?

Special thanks to Ashley Doscher and Matt Hale who submitted this image!