00:01
Now, let’s move on to the medial compartment
of the thigh. And we have a whole series of
adductor muscles, the medial compartment of
the thigh. We can see these are closely related
to pectineus. So we see pectineus passing
in this direction, as we mentioned, and we
have a whole series of adductor muscles, adductor
longus, adductor brevis, adductor magnus,
and also, gracilis. And here, we can see the
adductor longus is being cut. That’s the
most superficial of these adductor muscles.
And then running next the pectineus, we have
adductor brevis, and then we have adductor
magnus, we can see here. Most medially, we
have gracilis. Let’s look at their anatomy. If
we start off with adductor magnus, it has
two parts to it. And this is due to its origin
and its insertion, and therefore, the function
that it can carry out. So the adductor part
comes from the ischiopubic ramus. And it passes
to the linea aspera. So it’s going to the
linea aspera of the femur coming from the
pubic bone, the ischiopubic ramus. The hamstring
part is coming from the ischial tuberosity.
01:14
And this passes straight down to the adductor
tubercle. So if we were to look, we could
see that we have adductor magnus here. Part
of it is passing to the linea aspera, and
the hamstring portion is passing to the adductor
tubercle on the femur. So we can see because
of these two different insertions, it has
two different functions. The adductor part
can adduct the hip, and that’s innervated
therefore by obturator nerve, whereas, the
hamstring part can extend the hip, and that’s
innervated via the tibial nerve along with
the other hamstrings. Adductor longus sits
medial to pectineus, and this is from the
body of the pubis, and it attaches to the
middle third of the linea aspera. Adductor
brevis that also sits medial to pectineus,
and it’s coming from the body and inferior
ramus of the pubis. This attaches to the proximal
part of the linea aspera. We can see this here.
02:19
We see adductor brevis and adductor longus
both positioned medial to pectineus
running from the pubic bone across the various
parts of the linea aspera on the femur.
02:31
These are both supplied by the obturator nerve,
and they’re involved with adducting the
hip, so drawing the hip towards the midline.
We also have gracilis, and this comes from
the body and inferior ramus of the pubis,
so a similar position to adductor brevis,
and it passes to the medial surface of the
proximal tibia along with semitendinosus and
sartorius as we’ll see. This is innervated via
the obturator nerve. And as well as adducting
the hip, it’s also involved in flexing the
knee. Let’s look at these muscles in a bit
more of an anatomical orientation. We can
see now here more superficial dissection,
we have pectineus. Lying medial to pectineus,
we have adductor longus, and then we have
gracilis. If we were to cut adductor longus, we
would reveal adductor brevis, we can see here.
03:25
So now we have pectineus, adductor brevis,
and then we can see gracilis. We can also,
having cut adductor longus, see adductor magnus. If
we were to look on this more radical dissection
of the medial compartment where we’ve got
both adductor longus reflected and adductor
brevis reflected, we’ll see this large muscle
adductor magnus. And that really is separating
this medial compartment from the posterior
compartment. We can see it’s got its adductor
portion passing towards the femur. And we’ve
also got the hamstring portion that is passing
down towards the adductor tubercle on the medial
condyle of the femur. Notice this important
aperture here, and this is known as the adductor
hiatus, and we’ll return to it in a few
slides time. The medial compartment contains
the adductor group and it includes those muscles
that I’ve mentioned, adductor longus, adductor
brevis, adductor magnus, and gracilis.
04:27
The final muscle I want to mention is obturator
externus. And to look at obturator externus,
we have to look deep within the medial compartment.
Here, we can actually see we’ve got obturator
externus. We’re looking at this from the
posterior aspect. So we’re looking through
the hip on the posterior aspect. And this
is obturator externus. It’s coming from
the external surface of the obturator membrane.
So, obturator internus came from the internal
surface and it passed out via the lesser sciatic
foramen. This muscle is passing away and towards
the greater trochanter, obturator externus.
The adductor compartment is supplied by the
obturator nerve and it’s supplied by the obturator
artery. Adductor magnus is the largest
of the group and it has two parts I’ve mentioned,
adductor and hamstring. These have different
attachments, innervation, and function. Between
the distal adductor portion and the tendon
of the hamstring part, we have the adductor
hiatus. And this is an important passageway
as it is the exit for the adductor canal,
which we’ll see. This allows the passage
of the femoral artery and vein from the anterior
compartment to the popliteal fossa.
05:57
So it allows these anterior blood vessels to pass
posteriorly into the popliteal fossa.