0:00

Let's talk peroneus brevis

0:02

in the sagittal projection.

0:04

When we're up really high in the muscular

0:07

area, we've already said in another vignette

0:09

that the brevis is a little more posterior

0:12

than the longus. It's closely opposed

0:14

to the muscular unit, and it's deeper.

0:17

That is very hard to appreciate

0:19

in the sagittal projection.

0:20

As we go down in the axial projection,

0:22

they will trade spaces or places, and the

0:25

brevis will assume a more anterior position.

0:28

We can appreciate that in the sagittal

0:30

projection, where the brevis is now

0:32

clearly in the inframalleolar position,

0:35

more anterior than the longus.

0:38

It's also not as fat as the longus.

0:41

Now if we scroll a little bit back up, when

0:44

we get right in the retromalleolar segment of

0:46

the peroneus brevis, it's very hard to see.

0:49

And this is where many tears

0:51

begin and propagate from.

0:53

And the reason is, it's pushed up against

0:57

the back of the fibula, and especially if

0:59

you plantar flex the foot, it's even flatter.

1:03

So this segment of the peroneus brevis

1:05

is going to be flat and very hard to

1:07

visualize in the sagittal projection.

1:10

The reason that the sagittal projection still

1:13

maintains a level of importance is because

1:16

when you have big tears that retract all the

1:17

way up, you have to find where the brevis

1:20

is proximally, and nothing does that better

1:23

than the long-axis sagittal projection.

1:26

It does it better than the axial projection.

1:29

As discussed previously, we're going to have a

1:32

muscular segment of the peroneus brevis, then

1:36

a supramalleolar segment, a retromalleolar

1:38

segment, and then an inframalleolar segment.

1:42

And then a peritubercular segment,

1:44

which is very difficult to appreciate

1:45

in the sagittal projection.

1:47

And then finally a preinsertional and

1:49

an insertion on the base of the fifth.

1:53

Let's just for a moment look at the coronal

1:55

projection, which is not particularly

1:58

interesting to most peroneus brevis aficionados.

2:02

But we do have the brevis being a

2:03

little bit higher than the longus.

2:06

And sometimes you can just put your little

2:08

cursor over here to cross-reference where it is.

2:10

There's our brevis.

2:12

There's our brevis.

2:13

And occasionally it's nice to follow it

2:15

right into the tip or the base of the fifth.

2:18

Let's see if we can do that.

2:19

Here's the base of the fifth right here.

2:22

Let's go backwards.

2:23

There's our brevis.

2:24

Really hard to pick out because it gets so tiny

2:28

and attritional looking as it works its way down.

2:30

Now we go backwards.

2:31

It's a little more oval.

2:33

Now we go down.

2:34

It's a little more attritional.

2:36

And there it goes right

2:37

into the base of the fifth.

2:39

Of course, if you've got a Jones or a pseudo

2:41

Jones fracture, you better be looking at

2:44

the peroneus brevis in this projection too.