A few days ago I posted this:

And the answer is of course:

What’s the deal with blow-out fractures then?

• Typically from a blow to orbit and in particular the globe itself
• Classically this is from a squash ball (which I’ve seen twice now) or in this case a fist

Why is the inferior orbital wall affected?

• the orbit is pyrmidal in shape with the base of the pyramid facing you and the apex post in the skull. As the globe is forced backwards the walls of the orbit come under pressure

• Technically the thinnest walled part of the orbit is the medial wall and the ethmoid bone but the force in a blow to the globe tends to get redirected inferiorly rather than medially

What kind of problems can it cause?

• First look at this guys CT and take a guess [UPDATE - I suspect the muscle labelled inf oblique is actually inf rectus but don't worry too much about it]

• yes you’ve got it – opthalmoplegia
  • specifically difficulty in movements in the vertical plane. Even though sup rectus brings about superior gaze, the fact the inf rectus is trapped means that the eye is unable to be directed superiorly

Any other problems?

• direct globe injury – this is a whole topic in itself but in brief think fixed or irregular pupil, severe pain, and reduced acuity.
• orbital compartment syndrome – this is fairly interesting and worth a point or two
  • pressure can rapidly develop in the orbit either from oedema from the injury or a haematoma or build up of air in the orbital cavity from the opened maxillary sinus
  • the orbit it a fairly fixed compartment bounded by the bony walls and the globe and orbital septum
  • the pressure eventually will lead to an ischaemic and dead eye if not treated
  • treatment is surgical release, typically by a lateral canthotomy (that’s a fairly eye watering link by the way so be warned) - one of those procedures that Cliff Reid and Simon Carley suggested we should be thinking about in extreme situations.
• big time vagal reactions
  • sometimes these people can brady and faint on you. They can vomit lots and look terrible too and that’s all thought to be down to vagal stimulation. Which brings me to my next point…
• remember these patients have head injuries and ? brain injuries so that vomiting nd brady might not be down to vagal response but cushings reflex!
• and remember too that if they have a head injury then they might have a neck injury. Not from a squash ball though…

And now that you’ve read all that can I strongly suggest that you go and read a similar and much better post on the same topic over on LITFL.

A few days ago I posted this image:

Hopefully the small bowel obstruction is fairly obvious. The slightly more subtle part of it is shown below

Or in another view here:

Now some of you should be raising questions as to why a CT was done in the first place. You certainly don’t need a CT to make the diagnosis and go to surgery in all cases.

This lady had about a 12 hr history of belly pain with no vomiting or nausea. She was continuing to pass flatus and even her appetite was maintained! She was in significant pain and had some mild distension in the tummy.

Her X-ray was this:

There was a firm palpable mass about 2 cm across that was tender but felt more like an inflamed node than a hernia but when you hear hooves…

The mass was above the inguinal ligament and just lateral to the pubic tubercle making me think if it was a hernia it was an inguinal.

Surgeons weren’t particularly impressed to do anything that evening so she was admitted and my provisional diagnosis was incarcerated hernia.

I confess to being surprised when the CT came back next day with a femoral not an inguinal hernia.

So a brief review is in order.

Inguinal hernias:

• direct
  • a hernia that blasts straight through the post part of the ant abdo wall and out the superficial inguinal ring
  • will eventually extend into the scrotum along with the spermatic cord (or potentially labia in the female)
  • these are classically the ones in older folk caused by straining
  • classically found
• indirect
  • a hernia that emerges from the peritoneal cavity through the deep inguinal ring and runs along the inguinal canal till it eventually emerges in the scrotum
  • these are classically the ones with congenital weakness in the abdo wall

These are differentiated surgically as to whether they arise medial or lateral to the inferior epigastric vessels (branches off the femorals that run superiorly in the ant abdo wall)

Femoral hernias:

• found in the femoral canal – the potential space medial to the fem vein that is normally filled with fat and a small node. You’ve probably had your needle in there before when trying to place a femoral line.
• tend to be in females (wider pelvises and therefore bigger spaces) and tend to strangulate easier.
• these should be found below the inguinal ligament and medial to the vessels.

This picture should hopefully help. And if you scroll back up and look at the coronal CT image you’ll see the hernia just medial to the vessels and under the ligament.

But of course patients don’t read the books. Who could blame them…