- The design of your shoulder is unique and complex.
It's a ball and socket joint
that allows you a wide range of motion.
However, in order to maintain motion,
you have to sacrifice some stability.
It's this combination of mobility
and potential instability
that makes your shoulder vulnerable
to pain and injury.
The socket of your shoulder
is formed by part of your scapula
called the glenoid.
Your glenoid is shallow and flat.
To make your socket a little deeper,
a wedge-shaped rim of soft cartilage
called the labrum
surrounds the edge of your glenoid.
The labrum gives your humerus,
that is the ball portion of your shoulder,
a slightly deeper, more stable socket to rest in.
When you move your arm
or have a direct injury to your shoulder,
that soft labrum can get caught
between your glenoid and humerus.
And when this happens, your labrum can tear.
As the tear worsens,
it can create a flap in your labrum
that gets caught within your shoulder.
Labral tears are frequently associated
with shoulder instability,
that is, subluxations or dislocations.
Tears are a common source of pain
and a catching sensation in your shoulder.
Today we're going to take a more in-depth look
at the parts list of your shoulder
and how you can tear your labrum.
We're going to look at labral tear symptoms
and how they affect your daily life.
How we evaluate and fix labral tears.
The recovery process following a labral repair.
And finally, how to minimize your risk
of retearing your labrum.
Let's take a look at the parts list.
Here's the socket,
the shoulder blade,
the ball that sits in the socket,
the arm,
above the ball a bone called the acromion
that's connected to the collarbone.
Again, just to orient you,
here's your mouth, nose, eyes,
your armpit.
This socket, the bony socket
is rather shallow and it's made deeper
by this structure called the labrum.
And I'm going to just draw the labrum here
in three dimension.
There's the labrum,
and here's the middle of the socket.
Again, labrum,
which means lip in Latin.
Why don't we just call it lip?
I don't know.
Now, if we just take the ball out of the socket
and simply look at this labrum,
it looks something like this.
We'll make it larger.
Shoulder blade
and labrum in three dimension.
If we take this socket
and draw a line through the middle like this,
there are injuries of the labrum
that are in the top or superior portion
that we call SLAP lesions.
And then the injuries in the inferior
or bottom portion,
we call them Bankart lesions.
Bankart it's named after a Dr. Bankart
that wrote about these types of tears or lesions.
And SLAP stands for, ready for this,
the S stands for superior,
in other words, the tears that are
in the upper part or superior.
The L stands for labrum.
The A stands for anterior, that is, the front.
And the P stands for posterior or the back.
So these are tears or lesions
that are in the upper part, superior,
they involve the labrum
from anterior to posterior.
The most common SLAP lesions
are those that are a little bit in the back here.
And the most common Bankart lesions
are those that are in the front, about here.
Let's look at a common mechanism
for a Bankart lesion.
And perhaps you might think of it
as a quarterback who is in the position of throwing,
and just as he throws, he gets slammed.
As he gets slammed, right, the following happens.
Here's the socket.
Again, shoulder blade,
labrum,
middle of the labrum,
here's the ball.
And again, the arm is in an elevated position.
So the ball is being forced in this direction.
Here's the arm.
Arm's coming up like this.
Ball's being driven down this way.
And as a result, the labrum
gets torn in the front right here.
So again, this is a Bankart lesion.