So, for everyone, this is a 55-year-old male golfer who comes in with a right shoulder that's painful, swollen and has some redness and warmth to it, doesn't remember any trauma and gets an x-ray, which we can see on our screen here, and I probably can use the mouse pointer, but maybe I'll go to a laser pointer. Let's see, hopefully you can all see that. So, the x-ray really shows some calcium deposition here over the AC joint, and there also appears to be a kind of rim around the femoral head there, so that could be considered consistent with chondrocalcinosis. And so, the joint is aspirated and yields some crystals. First question is, these crystals should demonstrate what characteristics? And I'm just going to read through those characteristics in case there's people on the call who can't see the screen. The first characteristic is that they consist of calcium pyrophosphate. The second is that they exhibit negative birefringence. The third is that they're needle-shaped. And the fourth is that they consist of monosodium urate. Calcium pyrophosphate crystals was the correct answer, and we're going to go through the other answers just to look at why those were wrong. Picture here is of an opportune moment in history. You can see there, Sandy Lyle, the first Briton to get the green jacket by winning the US Open. So, that's what you get when you win the Masters. Sorry, it was the US Masters, not the Open. And if you want more information about that, there's a link to a website there. It was something that I remember growing up being a very famous moment for a Scotsman. But back to the crystals. Those are crystals of calcium pyrophosphate, and they are typically rhomboid or rod-shaped. With blunt ends, they are not needle-shaped. Monosodium urate crystals are the ones that are more needle-shaped, and those have negative birefringence on polarizing light microscopy. The chondrocalcinosis crystals have positive birefringence, and that is the difference between those two. And that's like a classic board question. You should be able to get that right fairly easily now that you've had a reminder. All right, we're going to keep moving with our case. This is a 59-year-old female tennis player, and she is presenting with an acute attack of pain in her ankle. It's very painful and swollen for the first eight or nine hours of symptom onset. You do the same thing. You have an aspirate of the joint and see that there are crystals with negative birefringence this time. There's also an ultrasound conducted, and this has that same double contour sign we can see here around the head. I think this is the first metatarsal, actually, and the first MTP joint. And there's also an ultrasound finding of clumps of sugar, which we'll also see on a subsequent slide. So those are the findings. The question we are going to ask you is, which of the following would not be considered first-line treatment for this condition, for this attack? So have a look through those choices and submit your answers. The first treatment is colchicine, Colchris. Second is ACTH. The third is NSAIDs, non-steroidal anti-inflammatory medications. The fourth is allopurinol. The fifth is corticosteroids. So five choices, which of those choices would not be considered first-line in treatment of this attack? The correct answer in this case was indeed allopurinol. That is not the correct answer because that is a controlling medication to prevent the uric acid levels elevating and you should not use that in an acute setting because it can just worsen the acute attack. All the other answers were correct, although certainly colchicine and NSAIDs are more typical. I have not seen ACTH used very often. Corticosteroids I do see used from time to time. The worst symptoms of gout typically do occur in that first eight to 12 hours. It's usually just one joint that's affected. We've reiterated the fact that the crystals are negative birefringent. Other things to consider if you get an x-ray of the joint, you will often see erosions. You can see in the highlighted slide here that podagra, the first MTP joint being affected, is common. An x-ray will typically show that the joint space is maintained. There's not narrowing of the joint space that you would see in arthritis. Typically no osteopenia, normal bone mineralisation, but you'll see erosions with overhanging edges like you see here in the bone around the joint. Ultrasound, as we said, will typically show wet clumps of sugar, which is well depicted here, and may also identify bony erosions. Again, allopurinol is contraindicated in the acute treatment of gout, but it's for long-term control.

2nd Edition, CASE 45

2nd Edition

Rheumatology

crystal-induced joint conditions

chondrocalcinosis

gout

birefringence

treatment options