EM REMS

A colleague pointed out an interesting CT on a patient with epigastric pain…

This CT shows stranding around the pancreas with fluid tracking in Gerota’s fascial plane.  What is Gerota’s fascia you say?

Gerota’s fascia (otherwise known as “Renal Fascia”) is the layer of connective tissue surrounding the kidneys and suprarenal glands.  Anterior to this fascial compartment is the prerenal space which contains the pancreas, ascending colon, descending colon, and the second-fourth portions of the duodenum.  Any inflammation with these organs can lead to fluid within Gerota’s fascia.  On the CT above this is demonstrated by the fluid stripe anterior to the left kidney on the middle image (sagittal plane)  and superior to the left kidney on the third image (coronal plane).  For an anatomic picture of Gerota’s fascia see the following Wikipedia reference:

Gerota’s Fascia

Author:  Russell Jones, MD

Image Contributor:  Tag Hopkins, MD

References

1.  Renal Fascia. http://en.wikipedia.org/wiki/Renal_fascia.  Accessed: 5/2013

This patient presented with nausea, vomiting, diffuse abdominal pain, and no bowel movement for a couple days.

This patient has a history of Ogilvie syndrome and this abdominal xray helps support this diagnosis.  Ogilvie syndrome is an acute pseudo-obstruction of the GI tract without a mechanical obstruction.  Xray will often show massive (>10cm) dilitation of the colon, usually on the cecal side.  This patient’s cecum measures out to be 21 cm!

Brief summary of Ogilvie Syndrome courtesy of Wikipedia:

Ogilvie

Author:  Russell Jones, MD

I posted a radiograph earlier asking about Bennett’s and Rolando fractures.  This is the patient’s CT obtained later to further characterize the fracture:

This is a Bennett’s fracture pattern.  Bennett’s is a fracture of the base of the 1st Metacarpal that involves the articulation and usually has some dislocation of the CMC (carpal-metacarpal) joint.  This fracture does have slight dislocation at the 1st CMC joint.

The Rolando’s fracture pattern is more comminuted, usually T or Y shaped comminution.  It carries a worse prognosis although the Bennett’s also has high incidence of arthritis even with optimal management.

Author:  Russell Jones, MD

This is a patient with pain in the thumb after punching another person:

Fractures of the base of the 1st (thumb) metacarpal are highly morbid injuries.  Most of these should be operative but many end up with severe arthritis of the MCP joint despite optimal therapy.  The thumb is a very important functional joint especially on the dominant hand, as in this patient.

Radiographically there are several eponym fractures for the base of the 1st metacarpal:  Rolando and Bennett are the most widely discussed eponym fractures.

Which one is this (if either)?

Answer to follow.

Author:  Russell Jones, MD

Another eponym fracture, courtesy of John Neuffer, MD at WVU.  Dr. Neuffer saw a patient with a fall on an outstretched hand (FOOSH) and this was the result:

This is an example of a Colles Fracture.  Colles fracture is a distal radius fracture with dorsal displacement of the distal fracture fragment and wrist.  FOOSH is a popular mechanism of this injury as well as any other mechanism that causes an axial load on the distal wrist with extension of the hand.

There are two other interesting parts of this image:  1.  There is an ulnar styloid fracture  2.  The pisiform is dislocated.

Ulnar styloid fractures are very common with FOOSH mechanism and in conjunction with distal radius fractures.  Common xray findings with a Colles fracture include (1):

• Transverse radius fracture
• Dorsal displacement and angulation
• Radial angulation of the wrist
• Location 1 inch proximal to the radiocarpal joint
• Radial shortening
• Ulnar styloid fracture
• Salter-Harris fractures in children

Pisiform dislocation is rare.  On the lateral view above you can see the pisiform is displaced off the triquetral bone (its only articulation).

This is what it should look like:

Pnormalpisform.png

(Above is a link to Wikipedia.  James Heilman, MD has a post about the pisiform with a great lateral radiograph demonstrating a normal positioned pisiform.  Go check it out!)

Author:  Russell Jones, MD

Image Contributor:  John Neuffer, MD

Thanks to Dr. Neuffer at WVU for the image as well as pointing out a good EM blog for me to follow:  EMchatter.com.  Keep up the good work and send me more good images!

References

1.  Broder JS.  ”Imaging the Extremities.” In: Broder JS.  Diagnostic Imaging for the Emergency Physician.  Elsevier Saunders, 2011.

A little while back I discussed Lisfranc fractures of the foot.  Here is an image depicting a fracture-dislocation through the Lisfranc joint:

This one is not subtle!  You can see that the bases of metatarsals 1-5 are laterally dislocated.  Remember, the Lisfranc joint involves articulation between metatarsals and tarsus (navicular, cuboid, and three cuneiform bones).  A Lisfranc fracture occurs when one or more of the metatarsals are dislocated from the tarsus.

As a reminder of the Lisfranc radiology findings here is a Word® document reminding us of the “Radiology Rules.”  It is in 3X5 card format you can print front and back and have a convenient reminder if you want to carry it with you on your clinical shifts.  That way hopefully we won’t miss the subtle ones…

Radiology Rule Lisfranc

Author:  Russell Jones, MD

I was working peds last night and an 8-year-old male came in with elbow pain after falling on an outstretched hand while playing football.  Another player fell on his elbow at the same time.  He had an obvious deformity and his elbow film is classic for an eponym fracture:

This is a Monteggia fracture-dislocation.  It involves a fracture of the proximal ulna and dislocation of the radial head.

Giovanni Monteggia (1814) originally described this fracture pattern.  It is usually associated with a direct blow or a hyperpronation, extension mechanism.  In this radiograph the radial head dislocation is obvious, however sometimes it can be subtle and missed.  Always draw a line through the radial head and make sure it intersects the capitellum on both the AP and lateral views (radiocapitellar line).  Here is an example of a normal radiocapitellar line:

Author:  Russell Jones, MD

The other day I posted radiographs of proximal metatarsal fractures and posed the question:  Is this the dreaded “Lisfranc fracture?”

It turns out that this is a complicated question.  Lets dive into what the heck a “lisfranc fracture” means.

The Lisfranc joint is another name for the tarsometatarsal joint of the foot.  It is named after Jacques Lisfranc (1790-1847) who was a surgeon in Napoleon’s army who basically pioneered amputating toes at the tarsometatarsal joint in order to treat gangrene.  The joint contains 5 metatarsals that articulate with 3 cuneiforms and the cuboid.  It is a complicated structure both radiographically and anatomically with mutliple ligaments and bones.  This poses difficulty in identifying exactly what is mean’t when people discuss the “Lisfranc fracture” or “Lisfranc fracture-dislocation.”

Anytime something has multiple bones it becomes difficult to identify subtle radiographic findings.  And it can be missed!  Subtle Lisfranc injuries can happen and can cause significant morbidity if not treated correctly, usually surgically.  There is a classification of Lisfranc joint injuries posed by Hardcastle et al (1) that is commonly used by our bone brotheren (orthopedics).  I refer you to their article for details.

Radiographically you can have multiple findings from subtle to obvious.  Here are some key points and things to look for:

1. Always obtain 3 views of the foot:  AP, lateral, and 30 degrees oblique
2. Weight bearing views can show subtle widening of articulation spaces and point out instability due to lisfranc ligamentous injuries
3. On the AP view, any diastasis of more than 2mm between the base of the 1st and 2nd metatarsals suggest Lisfranc injury
4. On the lateral view, the superior border of the base of the first metatarsal should align with the superior border of the medial cuneiform
5. On the oblique view, the medial border of the fourth metatarsal should align with the medial border of the cuboid
6. A “fleck” sign on the AP view, or an avulsion off the base of the of the second metatarsal or medial cuneiform is a sign of a Lisfranc ligament* injury
7. CT and/or MRI have been advantageous in radiographically subtle Lisfranc injuries

*The lisfranc ligament traverses the base of the 2nd metatarsal to the medial cuneiform.

The bottom line is these are highly morbid injuries if not treated correctly (and many times even if treatment is optimized).  Orthopedics will often take the patient for operative fixation in order to anatomically align the joint for best long-term result.

Lets re-visit our radiograph and identify if we are concerned:

Fig. 1:  (AP View) No diastasis of more than 2mm.  Also one can see that the lateral border of the 1st Metatarsal is aligned with the lateral border of the medial cuneiform bone.  The medial border of the second metatarsal is aligned with the medial border of the middle cuneiform bone.  This is good alignment and indicates the Lisfranc ligament extending from the base of the second metatarsal to the medial cuneiform is intact.

Fig. 2:  (Lateral view) The superior borders of the medial cuneiform and the base of the 1st metatarsal align

Fig. 3:  (Oblique view)  The medial border of the base of the 4th metatarsal aligns with the medial border of the cuboid.

If you look at all the criteria above you’ll realize that this gentleman only has non-displaced fractures of the proximal 3rd and 4th metatarsals, no signs consistent with injury to the Lisfranc joint.  Consider weight bearing views or CT scan in this case to fully rule out a Lisfranc joint injury.

For a good radiograph showing Lisfranc fracture-dislocation please refer to reference #2 below, or stay tuned and I’ll try and dig one up!

References

1.  Rijn J, Dorleijn D, Boetes B, Wiersma-Tuinstra S, Moonen S.  Missing the Lisfranc Fracture:  A Case Report and Review of the Literature.  J Foot & Ankle Surg 51: 270-274, 2012.

2.  Broder JS.  Diagnostic Imaging for the Emergency Physician.  Elsevier 2011.  Figure 14-123 Pg. 830.