Hello anatomy colleagues this is Dr Alsup and in this video we will discuss how to identify
the pertinent osteology or bony structures for the knee and distal lower limb session. So you cannot
have a session on the knee joint without talking about the bony parts that form the knee joint.
Recall the knee joint is going to be composed of two tibiofemoral articulations you can see
here with some of the associated structures as well as, well as a patellofemoral articulation.
So if we're looking at this anterior view of a deep joint dissection you can see here that the
patella has been reflected it's embedded in fact it develops within the quadriceps femoris tendon
and when it is not reflected it articulates with the patellar surface of the femur,
which is this very patellar-shaped smooth surface on the anterior and distal surface of the femur
so remember smooth surfaces likely tell you there was articular cartilage located there during life
due to a joint location. From this anterior view you can only see a small peak of the condyles
so this would be the medial this would be the lateral I can see the fibula
right here so I know that's lateral but I much prefer a posterior view of the femur for locating
the femoral condyles and my trick for determining which condyle is medial and which is lateral
is to always look proximally and find that hard to miss head of the femur which always faces medially
so the femoral condyle inferior to the head is the medial condyle the lateral condyle
is inferior to the greater trochanter which is always lateral.
You're likely used to this image of the patella which fits right on that smooth patellar surface
of the femur. Again this is the anterior surface of the patella which is always the rougher side
you can see kind of the bone is kind of built up a little more here and the posterior side
is the one that's actually articulating so it will be smooth as it had articular cartilage
associated with it during life. The point of the patella is always directed inferiorly.
Moving to the tibia with which is important for not only the knee joint but also the ankle joint.
This is the medial and weight bearing bone of the leg. The proximal end will be involved with the
knee joint allowing the femoral condyles to sit on their own condyles you can see just how shallow
these condyles are. So that fit between the the femoral condyles and the tibial condyles is not
a very tight fit. The way I quickly differentiate between the two is that the medial condyle is
always on so this is the medial condyle and I know that because it's always on the same side
as the medial malleolus or malleolus all right so that's always the this one will always be
the medial one this will be the lateral condyle. Again this is the medial malleolus
which is on the medial side of the ankle joint region you can palpate your own medial malleolus
on the medial side of your own ankle. This distal and an inferior most portion of the tibia
is what will actually articulate with the talus or the talus.
Now on to the much thinner and non-weight-bearing fibula which is the lateral bone of the leg.
On this distal end here of the fibula the dominant structure is the lateral malleolus or again malleolus.
So it's less bulbous in shape and more tapered than the proximal head of
the fibula so one of the more difficult things is differentiating which side is
what's superior and what's inferior what's proximal and what's distal and really that lateral
malleolus tends to be a little bit kind of longer and more tapered than the head of the fibula.
Lastly we get to the foot and there are two tarsal bones we expect you to be able to identify.
The superior most tarsal bone shaded here in pink is the talus or the talus which when
you look at its superior surface which I just put this big T on is almost all
smooth so the surface here is going to be an articular surface that distal tibia will
sit right here to form the talocrural or ankle joint. You can also see the talus or the talus
on this from this medial view here as well so you can kind of see the entirety of its shape.
Where the tibia kind of rested on the talus the talus rests on the largest tarsal bone
the calcaneus often thought of as the heel bone and you can see it shaded here in orange and
you get an appreciation of really how large this bone is if you think of this bone compared to any
carpal bone it's you know you could fit almost all the carpal bones right here on the calcaneus.
And if you think when you're standing up a lot of that weight ends up kind of resting
in that calcaneal region. You can also see it here from this medial view and notice
this bump that leads into kind of this robust region right here
and this is where the calcaneal or achilles tendon will attach. Alright excellent thank you all so
much for your time and attention here and please always feel free to reach out with any questions.