0:00

The common peral nerve will diverge from the sciatic trunk

0:03

in the upper upper popal fossa.

0:06

So here you start the, they start separating

0:09

and it will descend in the posterior lateral knee, intimate

0:13

with the biceps, urs, and lateral head of the gastrocs.

0:16

And it will then turn around the fibular head

0:19

and will trifurcate into a superficial deep

0:22

and deep, uh, branches and a recurrent articular branch.

0:27

So this is a magnified, uh, image

0:30

of the posterior lateral aspect of the knee,

0:33

showing the common peral nerve between the bice muscle

0:38

and the lateral head of the gastro anemia.

0:40

So you can imagine in a patient with very muscular,

0:43

in an athlete, uh, the muscle hypertrophy can compress, uh,

0:48

the common perineal nerve.

0:50

The common common perineal neuropathy is the most common

0:53

neuropathy of the lower extremity.

0:56

And in this example, for ex,

0:58

there is a ganglion cyst compressed,

1:00

seeing the common perineal nerve leading

1:02

to denervation changes and a foot drop clinically.

1:07

This is another example of a patient who had an injury

1:10

to the common perineal nerve.

1:12

And notice here how you lose the physical appearance

1:17

of the, uh, nerve.

1:19

And the nerve is surrounded by this hypo intense rim,

1:22

either some fibrosis or hemosiderin.

1:25

And you can see distally the denervation changes

1:29

in the anterior

1:30

and lateral compartment corresponding to the

1:33

denervation changes from the common peral nerve.

1:38

So right after it turns around the fibrillary head, the, uh,

1:41

the common peral nerve will trifurcate,

1:45

it will give off the deep perineal nerve,

1:47

which is more anterior and medial,

1:50

and that nerve will descend along the anterior anter ossis

1:53

membrane with the anterior tibial artery

1:55

and it's mostly motor.

1:57

The superficial perineal nerve is located deep

2:00

to the perineal longus muscle

2:02

and will, uh, supply the perineal, perineal revis

2:05

and longus muscles and then will, uh,

2:09

further down in the distal aspect

2:11

of the leg will become superficial and only sensory.

2:16

And finally, the, uh, third branch of the, uh,

2:19

common peral nerve is the recurrent articular branch was

2:23

just very difficult to see on, uh, MR imaging

2:26

because it has this horizontal course, uh,

2:29

around the fibular, uh, neck.