0:00

The next group we're gonna

0:01

Look at is the extensor. So

0:03

The main thing that we wanna talk about in the extensors

0:06

is the hamstring tendons.

0:08

The gluteus maximus is also an important extensor,

0:12

but it doesn't really have a dominant, uh, tendon.

0:15

Uh, it inserts via very short, uh, tendonous slips, uh,

0:20

onto the femur as well as onto the ilio, uh, tibial tract.

0:24

And we don't see many injuries involving

0:26

its tendonous structure.

0:28

So at the isum,

0:30

we're gonna look at the hamstring tendons.

0:34

You're usually gonna see two components.

0:36

You're gonna see the semi menos tendon anteriorly

0:41

and the conjoin tendon, which is made up

0:44

of the semi tendonosis and biceps fems posteriorly.

0:49

Now, when you look at anatomy pictures,

0:51

it gets really confusing

0:53

because the anatomy pictures will often show the

0:57

semimembranosus located above and the conjoin tendon below.

1:01

And I think it's important to keep in mind

1:04

that the pelvis is at a tilt.

1:07

And so because of that tilt,

1:09

your semi menos is gonna project anterior

1:12

to the conjoin tendon.

1:14

It does have a higher insertion,

1:16

it goes further cranial than the conjoin,

1:19

but it also looks like it's anterior.

1:22

These are intimate here with the sciatic nerve,

1:26

which is labeled on this image,

1:29

and you can see, uh, abnormalities of the sciatic nerve,

1:33

either in the setting of acute trauma or post-surgical.

1:38

In patients who have undergone reconstruction

1:41

of hamstring tears, the adductor magnus

1:45

is continuous with the semimembranosus, there are fibers

1:49

that allow it to communicate, uh, that string along

1:54

the adductor magnus itself inserts more

1:57

inferiorly along the ender surface of the isum.

2:01

It can be torn with the hamstrings

2:04

as we see in this example.

2:05

This is an old case, but I like this example because

2:09

It's a bilateral avulsion of all of those structures.

2:13

And this was a patient who was injured

2:15

During a, Uh, water skiing injury,

2:18

which is a classic mechanism for developing bilateral

2:22

hamstring, uh, avulsion.

2:26

We can see injuries in young people involving

2:29

the hamstring insertion.

2:30

This is the most common of the apophyseal injuries

2:33

that we encounter.

2:35

In this case, it's low grade without any significant

2:38

displacement of the apophysis.

2:40

We do see altered, uh, signal within the apophysis,

2:44

which is emus some bone edema and soft tissue edema.

2:48

But this apophysis can displace and it can displace quite

2:52

Far. You

2:53

Know, this is a different patient

2:55

who had sustained an physeal injury as a child

2:59

and notice this huge mass of ossification

3:03

below the isum.

3:04

So this can be confused with a neoplasm.

3:07

Notice that there is a defect in the underlying isum.

3:10

So you can see this, it can be symptomatic,

3:13

resulting in is femoral impingement.

3:16

Uh, and, uh, don't, uh, confuse this mature

3:20

tropic ossification with corticated margins

3:23

for an aggressive, uh, neoplasm.

3:25

Comparing the ischial morphology on the two sides can

3:29

certainly, uh, be helpful.

3:31

Now in terms of hamstring tendon tears,

3:34

these have the same type of features

3:36

that we see at the rotator cuff.

3:38

We can see tearing within the tendon itself,

3:42

but we also get lesions that look like a peel off.

3:45

And I think the peel off type lesion is important,

3:48

where the tendon itself doesn't look disrupted,

3:50

but it no longer inserts normally onto the bone.

3:54

It's a stripping type of injury.

3:56

This can be a little confusing if you're not familiar

4:00

with looking at it.

4:01

Uh, but, uh,

4:03

there should be a long greater than 15 millimeter length

4:07

of insertion of the semi menos to this flat facet

4:12

along the is gim, and it's been completely peeled off.

4:15

And then we have more conventional type

4:17

of tearing in the conjoin here that we're used to with, uh,

4:21

edema, uh, within the tendon and tendon, uh, irregularities.

4:26

We see these types of tears generally in our older

4:29

patient populations.

4:31

They may be full thickness

4:32

and complete as we see in this example

4:35

where the tendons are retracted

4:37

with associated hematoma within the thigh.

4:41

And it's nice if you don't see the ends of the tendons,

4:44

if you happen to be monitoring the exam to

4:47

go down low enough so that you can measure the gap

4:50

because that's an important, uh, uh, finding for the surgeon

4:54

who is considering a reconstruction,

4:56

how to plan their surgery.

4:57

Knowing how big the gap is, I think we tend

5:01

to under call these tears.

5:03

Again, the lesions are often a peel off like this.

5:06

The tendon itself doesn't have a lot of fluid in it,

5:09

but it's no longer attaching normally to the isum.

5:14

And this patient underwent a surgical, uh,

5:17

reconstruction, uh, of the tear.

5:20

One of the reasons we have this problem of under grading,

5:23

particularly with the conjoining tendon, is that the

5:28

sacral tubus ligament inserts directly onto the conjoining

5:33

tendon and it prevents retraction even in a complete tear.

5:37

I think an intact adductor magnus prevents retraction

5:41

of the semimembranosus,

5:43

and that's some of the reason that it doesn't go down

5:45

very far distally.

5:47

But in any case, be aware

5:49

that you can get this complete stripping,

5:51

but the intact tendon holds it in place

5:55

and it doesn't look

5:56

Like it is retracted.

5:58

Here's an example here.

6:00

The tendon is not attaching at all to the bone,

6:03

but it's not retracted

6:05

because of that continuity

6:07

with the sacral tubus uh, ligament.

6:09

So be cautious with these.

6:11

I like to use the sagittal images

6:13

and the coronal images the most to make sure

6:16

that there is a solid touchdown of the tendon.

6:20

In terms of the gluteus medias, again,

6:23

only a few words about it.

6:24

It really has no significant tenderness, uh, uh, injuries.

6:29

Usually we'll see muscle contusions,

6:32

but you can see calcific tendonitis, uh, of this tendon.

6:36

It's very painful.

6:38

And this particular tendon has very strong

6:41

intraosseous extensions.

6:43

So the calcific tendonitis can be associated

6:46

with cortical irregularities and marrow edema.

6:50

And I've seen this confused with metastatic disease.

6:54

So be careful with this like the pectoralis.

6:57

This can be associated with deformity of the overlying bone.