Scaphoid shmaiphoid! What even is it?
So you think you might have a scaphoid fracture and want to know what all the fuss is about?
Firstly, what is the scaphoid? The scaphoid is the most important bone in your wrist. The name comes from the Greek word Skaphos which means boat. As it looks like a boat! It plays a pivotal role in maintaining smooth, powerful wrist motion. Its also important for a number of other reasons:
- When the wrist is injured, this particular bone is often in trouble
- It has a funny blood supply
- It's a slow healer
- If it doesn't heal properly it will lead to problems such as pain and arthritis down the track
It's can be injured when you fall onto your outstretched wrist, more common in younger patients than older patients. Older patients tend to break their wrist instead of their scaphoid, as their bones are often more brittle.
When it breaks it usually breaks in the middle, or the waist. And this is why the blood supply to it is important. A lot of the blood to the proximal bit (that is the bit closest to the forearm) comes from the distal bit (that is the bit closest to the fingers). So when the scaphoid breaks in the middle, there is a risk that the blood supply to the proximal bit will be compromised (see diagram below). Blood brings food to the bone, so without its blood supply the proximal part may "die". When a bone "dies" it can no longer heal itself and changes consistency from a nice edam cheese to a hard cheddar and starts to crumble leading to arthritis and pain.
Could mine be broken!?
Now you're a little bit worried and thinking: "I had a fall and now I have a sore wrist!! Maybe I have a scaphoid fracture!? How would I even know??"
Well to start the ball rolling, a simple x-ray can be useful, and would reveal most scaphoid fractures. But unfortunately x-rays don't show all scaphoid fracture, especially the subtle ones. This bone is so important that even if the x-ray comes back clear, but your wrist is still proper sore, then it may be worthwhile getting an MRI to really know for sure that the scaphoid isn't broken. As missing a scaphoid fracture really causes a lot of heartache down the track.
Ok doc! I have a scaphoid fracture!! Now what?
Well to know how to best treat your wrist, we need to know a few things: When do you think you broke it? Which part of the bone is broken? Is it displaced or not?
The timing of the injury makes a difference. The longer the scaphoid has been broken (ie months vs days), the more unlikely it is to heal without surgery and the more involved the surgery becomes. If it's been a short time since it was broken (less than 4 weeks) then there is a reasonable chance we could get away with just a plaster cast. If it's been longer than 4 weeks than we really need to consider surgery
The more proximal the break is, the more we worry about the fracture as again it's less likely to heal. This is because the more proximal the break is the more likely the bone is to loose its blood supply and the more the fracture pieces move against each other and prevent healing.
We also look at displacement. Displacement refers to how far apart the broken bits are to each other. The further apart they are or the more angulated they are, then the more likely it is that you need surgery.
In summary; if its a recent fracture, that's not near the proximal end and it hasn't displaced too much, we use a cast to treat it, otherwise we have to think about surgery. Luckily most fractures fall into this category.
What's involved in a cast?
The cast is usually made of fibre-glass or plaster and keeps your wrist still, stopping the bone ends from moving against each other. Usually it's not waterproof (so you have to cover it in the shower) and you usually need it for at least 8 weeks. Seems like a long time, but if you consider the earth was made billions of years ago, then really 8 weeks isn't that long.
What's involved in surgery?
That's a hard one to answer as there are a lot of variables that decide what surgery is needed. Broadly speaking we treat the fracture by putting a screw across it. However lots of other things need to be taken into consideration. If the fracture is displaced, we need to put it
back together first, which means opening up the wrist. If the fracture is old, then we need to put bone graft in there to make sure it heals, and often we either take that out from one of the other bones near your wrist (the radius) or from your pelvic bone. Also sometimes the fracture is so old that it's caused arthritis to set in, if that happens then we've kind of missed the boat (pun intended) on fixing the scaphoid and have to think about other types of operations (salvage operations) to help stop further progression of arthritis and pain. These usually include taking the scaphoid out and fusing some of the other bones.