Clinical Case 101: Going Glass Hunting

Broome is a fun place – it is always warm, the locals are nearly pathologically “laid back”.  Shoes are worn by fewer than 50 % of the populace!  This creates a few common ED scenarios.  Foot infections and injuries are common – especially the “glass foreign body in foot” scenario.

Now – I remember when I was an intern working in ED and I spent an hour digging, probing and ‘excising’ a never-seen glass FB from a chap’s foot.  It was torture – he felt it all and I simply did not know better.  However, I still see the ever-frustrating “glass hunting” on a regular basis happening in my ED.

So I thought I would share a case – to show how I roll now when chasing FBs in feet.

Here is the case.  Nice young lady with no medical problems – she was at a party and trod on some glass from a broken bottle 3 days ago.  No shoes, as is the norm.

She slept and awoke with a sore foot – she can feel pain on every step over the heel.  There wis a small skin puncture – and she has had a go at probing it with a sewing needle [which she ‘sterilised’ with a cigarette lighter].  But – no luck – she is still limping on the ball of her foot.  No apparent infection.

So how would you approach this?  Any imaging?  Or just have a probe?  Would you attempt to anaesthetise the area?

Well I have seen a lot of techniques over the years – and this is how I play it in 2014.

(1)  Always image.  Ultrasound is great for small FBs – but there are a few tricks that you need to be aware of.

  • High frequency probe, dialled up to the shallowest depth it will do.
  • Turn OFF the multi beam / image-enhancing / optimisation software – these will make it harder to see the shadow artefact that you are looking for.
  • Here’s a previous post where I discuss why this is important.
  • Use a heap of gell to get a “Stand- off” between the skin and the probe – also fills in any skin cracks / breaks that might spoil the delicate high freq image
  • Or put the foot in a bath of water to allow completely excellent transfer of sound waves.

You could get a plain film XR if the US isn’t working – problem is that it does still make it tough to decide exactly where that little shard of glass is in the skin.  And the next few steps use US anyway!

(2) If you see a FB – great! Move to step (3).  IF you cannot see a FB despite your best image effort – then you need to seriously consider stopping at this point.  It may be that there is NO FB! That the patient is just feeling pain from a clean cut that has no FB or a trivial speck of dirt within.   In my opinion this should  not be explored.  It will declare itself  if you are missing something too small to see on US.

(3)  OK so there is a FB – cool.  Now you need to orientate the lie of the FB.  Get the angle, the depth, the direction all clear in your head – because once you start digging – it can be tough to say where and what you are doing.

(4)  Before you start digging – do a nice simple posterior tibial nerve block.  It is easy.  You could do it blind – but you have the probe right there and there is some evidence to suggest that US-guided blocks of this nerve work better than the “landmark” blocks.

  • If you want to know how: check out the Sonoguide site here
  • If you want to see why I think you should do it under US-guidance – see this paper from Redborg et al
  • If you are still not convinced – then listen 
    My wife and I were serious mountain trekkers before kids!One year we were training hard for a tour around Nepal when she developed plantar fasciitis – overdoing the new boots! So being a young, keen anaesthetic Reg – I volunteered to do a steroid injection – under a posterior tibial block. It seemed humane, and would mean we were ready for the Annapurna circuit next week! But I did not have and US in our bathroom as I did the block! And I managed to skewer the nerve directly with my block! Ouch – direct hit and neuronal injury. I proceeded to do the steroid injection (pain free) but she was left with a numb sole…. until a week later when she developed a painful shooting dysaesthesia into her foot with every step! So off we went to beautiful Nepal….. and it was a long road, with plenty of pain and guilt… So take my word for it – use the US to avoid intraneural injection or nerve injury

(5)  Put in the block and then go and see the next patient.  These blocks take 10 – 20 minutes to get to best effect.  So take your time and your patient will feel less pain.

(6)  Now there are a few techniques for getting the glass out.

  • If you can see it / grab it  with a small nick in the skin – great.  However, this is usually not the case.
  • You can use the US to slide a small needle under the FB – so you have a guide.  Then just cut down onto the needle shaft and it should pop into view.  Here is a paper from Kenechi Nwawka and colleagues in Journ of Foot & Ankle Surg, 2014 describing this in a few nice cases
  • If there is already a mess of skin from previous attempts – I am not too proud to simply excise a small ellipse of skin and core of sub cut tissue  – FB included.  You can then just close it with a few stitches.

The really sexy part of this is step (7)

(7)  Now get your probe and rescan the patient’s foot.   The FB should be gone.  Or you can put the it of skin into a bath and scan it – and the same FB you saw before should now be in the specimen!  Magic – patient’s love seeing this bit.

(8)  Never perform surgical procedures on your wife at home.  Even on a good day this will lead to pain and suffering.  It is just not cool. Do not do it!


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