Gross anatomy LE knee

• Popiteal fossa – diamond shaped
• area/hole on the back of the knee – border
• medial side – medial hamstrings
• lateral side – lateral hamstring (biceps femoris)
• Bottom sides made by the heads of the gastrocs and the plantaris.

• Popiteal artery and vein
• and the sciatic nerve turns into the tibial nerve and the common peroneal nerve at the top of the fosa.

Common peroneal nerve- A palsy in this area caused by something like a tight cast can cause foot drop, slap foot gait and other gait changes do to a lack of eversion and dorsiflexion. This nerve supplies the lateral side of the lower leg and the frontal side of the leg on Tom, dick and harry and peronious longus and brevis on the side.

Tibail nerve dives under the soleus and innervates it so a common sign of a tibial nerve lesion is a lack of push off of the foot when walking and hence a lack of plantar flexion.

Medial and lateral sureal nerve (or short saphenous nerve)– comes through popliteal fossa and they come down and blend into one sureal nerve that goes down the center of the calf and then goes to the lateral side of the foot.

medial side of the foot is the sapherious nerve which comes of the femoral nerve. This can be cut when harvesting the saphrinous vein for coronary artery bypass grafts

Lesser saphrinous vein comes straight down the back side of the calf.

Fibula – does not bear weight so has nothing to do with the knee.

If fibual is removed tibia will break easier with torsion because the fibula acts as a brace, but it loss won't effect gait.

Intercondylar fossa of femur - In front, the condyles are but slightly prominent, and are separated from one another by a smooth shallow articular depression called the patellar surface; behind, they project considerably, and the interval between them forms a deep notch, theintercondylar fossa (or intercondyloid fossa).

– is the lump on the lateral condyle and is were the IT band inserts.

• Knee
• Joint – is a massive synovial hinge joint – is made of three joints

Pattel femoral joint – patella lateral tibial femoral

medial tibial femoral joint

(its a weak joint, because It just two bone sitting on top of each other so it easy for the femur to slide on the tibia hence why it has big thick ligaments to maintain it.)

Knee/lower leg can rotate a little – rotates more in flexion then in extension were it locked and immobile.

Locking/unlocking the knee for stability – as you extend the knee during the last 10-15 degrees the femurs are going to rotate medial if your feet are planted on the ground, such as in a sit to stand motions (closed chain exercise) this locks the knee.

In open chain were the but and hence the femur is fixed and the tibia will rotate laterally during the last 15 degrees of extension hence stabilizing the knee. When you want to bend the knee you need to unlock the knee this is the screw home mechanism– you laterally rotate the femur to allow knee flexion or in an open chain position you medial rotate the tibia. There is a muscle thats job is to unlock the knee joint this is the poplitealus.

• Locking/unlocking the knee for
• stability – as you extend the knee during the last 10-15 degrees the femurs are going to rotate medial if your feet are planted on the ground, such as in a sit to stand motions (closed chain exercise) this locks the knee.

In open chain were the but and hence the femur is fixed and the tibia will rotate laterally during the last 15 degrees of extension hence stabilizing the knee. When you want to bend the knee you need to unlock the knee this is the screw home mechanism– you laterally rotate the femur to allow knee flexion or in an open chian position you medial rotate the tibia.

There is a muscle thats job is to unlock the knee joint this is the poplitealus.

Arcurate ligament – means arched ligament, so something goes through it. This can be found in flexor carpi ulnaris and the ulna nerves passes under it and in the LE under the poplitealus muscle.

arcuate popliteal ligament is an extracapsular ligament of the knee. It is Y-shaped and is attached to the fibular head. From there it goes to its two insertions; one goes over m. popliteus and attaches to the intercondylar area of tibia, the other to the lateral epicondyle of femur and blends there with the lateral head of m. gastrocnemius.

Incorrrect tracking of the patella – do to one quad becoming stronger then another quad muscle (can cause an imbalances of the force on the pattela) or often the VMO get weaker or shut down (causes lateral tracking) . This causes the patella to be pulled through its motion slightly out of place and this can cause it to wear away causing anterior knee pain pain.


VMO – is inhibited by pain so a sore knee turns of the VMO instantly and then the vastus lateralis will start pulling the pattela over. Also shut down by swelling in the knee, all of these can effect the tracking of the knee.

Test – hold the patella while they flex and extend the knees to see if it tracking correctly

Treatments: tape the knee to help relieve pain. Also can selectively strengthen the quads , though things like weighted leg lift while sitting. In extreme cases you can drill holes in the back of the patella to get blood there and start the regrowth of the knee.

• So to fix this we need to strengthen the VMO without strengthening everything else. To do this we can do
• exercises such as

• short out quads – sit and lift foot with weight on foot
• Little squats with ball between the knees.

Quadriceps angle – go to the tibial tuberosity and draw a line straight up to the center of the patella, then extend that line upward following those line straight up. Then draw a line to the ASIS. These lines represent the pull on the patella by the quads and hopefully this is straight up and down the grove the difference between the two lines is the Q angle which should be around 15 degrees (greater in females due to wider hips (valgus or knock knee also increase it)) Over Prontion of the foot will also increase the Q angle which can lead to incorect pattella tracking and knee pain

So one treatment for anterior knee pain would be to change the pronation of the foot. Some people tibila tubersity is in a weird spot and the this can also create a greater q angle and the greater this angle the more chance there is for the patella to wear away.

• pattela ligament
• medial (or tibial) collateral ligament
• Lateral (or fibula) collateral ligament
• Anterior Cruxiate ligament
• Posterior Cruxiate ligament

pattela ligament on the front of knee – goes from the patella to the tibial tuberosity – Reinforces the anterior aspect of the knee joint, and is the continuation of the qudriceps tendon. - transfers the force of all the quads muscles through the tibial tuberosity

• extracapsular ligaments –
• tibial or medial collateral ligament – reinforces joint capsule – thickenings of the joint capsule unfortunately sense it connects to the joint capsule and the capsule connects to the medial menisci something that damages one can damage them all. It a flatter thinner ligament then the fibula collateral ligament in the knee looks like a thickening of the capsule.

Lateral (or fibula) collateral ligament – pencil like ligament thin and strip like it inserts onto the fibula head and does not merge with the joint capsule. It goes to top of fibula and passes through the biceps femoris which form a y around it. 5 cm long – not hurt as much as the medial colateral ligament for varus force is needed to rip it.


Lateral collateral ligament is the thinner one. Medial collateral ligament is is flatter and wider and is torn more often due to valgus force. These ligaments tighten during extension, knees lock and slacker in flexion of the knee.



Cruxiate ligaments – are in the capsule but outside of the synovial capsule , because the synovial membrane fold around these ligament so that no synovial fluid touches them. Hence they are extra synovial but intracapsulor.


Anterior cruxiate ligament – prevent hyperextension of the knee and lateral rotation of the femur on a fixed tibia will twist these ligaments around each other.

Posterior cruxiate ligament

Lateral rotation on a fixed tibia twist the ACL , hence common injury often in women is tearing of the ACL's (caused when they running down the court ball in hand and plant foot with the knee in extension and twist your femur around the tibia to pass and this twist the ACL around the PCL and the tightening pops the ACL )


Acl – stops extension, lateral rotation and anterior translation of the tibia or posterior translation of the femur.

O'Donoghue's triad – or the unhappy triad – the 3 C's – cartilage (medial meniscus) ,Cruxiate (anterior cruciate ligament or ACL ), collateral (medial collateral ligament or MCL ).

O'Donoghue's triad or a "blown knee") is an injury to the anterior cruciate ligament, medial collateral ligament, and the meniscus. The triad refers to a complete or partial tear of the anterior cruciate ligament, medial collateral ligament, and the meniscus. Originally the "unhappy triad" included the medial meniscus and not the lateral meniscus. However, during the 1990's, analysis indicated that the 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. In this type of injury, acute tears of the medial meniscus always present with a concomitant lateral meniscus injury. However, the lateral meniscus tears are far more common than medial meniscus tears in sprains of the ACL.

• Rarely damage lateral collateral due to
• evulsion fracture (which is when the bone rips of because the ligament is stronger then the bone)

anterior and posterior crucitate ligaments

The anterior cruxiate comes of the anterior side of the tibia and goes back. The posterior cruxiate comes of the posterior side of the tibia and goes forward to inserts on the femur. So they cross in the saggital and frontal plane.


PCL – starts on the back goes forward upward and insert onto the lateral aspect of the medial epicondyle.

• ACL – starts on the front of the tibia and goes up backwards and laterally and insert on the inside of
• the medial aspect of the lateral epicondyle.

• Test for ACL – pull lower leg forward – old classic test was the anterior draw test which was when a pt lies on plynth with leg at 90 degrees and someone sits on your foot and pulls on the tibia to see if comes forward or not , the problem with this test is that the hamstrings can come on and give a false negative reading. - sit on foot and pull on foreleg, but this can
• activate the hamstrings. lie on the back with the knee bent and pull on the foot

Lachman's test – the current common test for the ACL – the pt lies on back and person lifts the foot with knee bent and then pull on the tibia. Machines can do this for you.

• Lachman test
• The knee is flexed at 30 degrees

Examiner pulls on the tibia to assess the amount of anterior motion of the tibia in comparison to the femur

An ACL-deficient knee will demonstrate increased forward translation of the tibia at the conclusion of the movement

• extension,
• lateral rotation
• anterior translation of the tibia or posterior translation of the femur.

The function of the PCL is to prevent the femur from sliding off the anterior edge of the tibia and to prevent the tibia from displacing posterior to the femur. Common causes of PCL injuries are direct blows to the flexed knee, such as the knee hitting the dashboard in a car accident or falling hard on the knee, both instances displacing the tibia posterior to the femur.

prevents anterior translation of the femur or posterior translation translation of the tibia.

• PCL – restricts flexion, medial rotation and posterior tranlsation of the tibia or anterior translation of the
• femur.

Can be broken in hypertension but this rarely occurs. More often broken do to car crash when something whacks the tibia.

Tests:

posterior draw – push the tibia back ward – sit in hook lying position and push on the tibia. Machine can do this as well.

Sag test – another PCL test - lie on back with the thighs at 90 degrees, and look at the tibial tuberosities and you lower legs should be parallel. If one tibia is sagging down a lot lower then the other then that PCL may be damaged.

Arcuate popliteul ligament – thickening of the joint capsule that comes across covering the origin of the poplitealus muscle.

Oblique popliteal ligament (medial side) – big thickening of the joint capsule on the posterior surfaces it blends with the semimebranous tendon (on back medial aspect of the tibia)

Meniscofemural ligaments

• Posterior meniscofemoral ligament – (also called the ligament of wrisberg) – it attaches to the back side of the lateral meniscs (most people have this ligament) it
• function is debated it may stabilize the lateral menisics, it does this in pigs but not sure if that what it doe sin humans.

Anterior meniscufemoral ligament – runs parallel to posterior meniscofemoral ligament but on the other side deep and anterior to the posterior meniscofemural ligament – (also called the ligament of humphrey) they think it stabilizes the lateral menisci, it goes around the PCL and if you rip the PCL these ligaments can partial replace its functions and stabilize the knee, but they not as strong.

Menisci – semilunar cartilage – half mooned shaped cartilage – the lateral one in the knee is almost a complete circle – the medial one makes more of a C , more open on the medial margin. Made of fibrocartilage –in cross section they are flat on bottom and concave on top. Thick on the outside thin on the inside and taper of into nothing on the inside. Joined by coronary ligaments on the outside which hold them to the joint capsule. Stabilized on the outside or lateral margins. The medial meniscis blends with the tibail collateral ligament, hence why a tear in it can tear the joint capsule.


Transverse ligament of the knee – hold the menisci cartilage together, joins them.


Mensics – are shock absorbs and increase joint congruency.

• Lateral menisic is more moveable so
• doesn't got caught as much as the medial. In the old day the medial meniscus would be cut out when damaged but this lead to arthritis. In the old days they just cut out part of it but this leads to arthritis, so these days they suture it and take as little as possible , to help keep the joint stable.

Test for mensici – grinding tests.

Bursea – is greek for wine skin – it is a synovial filled capsule. 3 big important ones on the front of the knee

subcutaneous preppattellar busra – commonly get bursitis from kneeling down a lot

infrapattellar subcuaneous bursa

subtendinous infrapattellar bursa

House maids knee or carpet layers knee – subcutaneous preppattella bursitis – swells to the size of a egg on the front of the pattella – you get this from kneeling down a lot.

Clergymans knee - subcutaneous infrapattellar bursitis - get this inflamed from spending all day long on your knees praying

Baker cyst – a swelling in the back of the knee. Knee joint is a synovial joint and inflammation of it from mesnical or cruxiate tear or from osteo or rhematoid arthritis you can get an expansion of the synovial fluid back into the popiteal fossa. They doesn't usually hurt, often left alone because if the synovial fluid is drained it tends to come right back, plus draining it may cause infection– to treat it you have to address the issue in the knee – may give them steroids. Can be confused with a a dark blue swelling that look like a bruise because this might be bleed and this can lead to clots which can travel tot he heart.

pathology - If medial maleoulus is at the same level as the lateral maleoulus you have broken you ankle because the lateral malleoulus should be lower.

Anterior tibiofibular ligament – keeps the force from the calcaneous through the talus from spitting the tibia and fibula apart.

Anterior and posterior fibula head ligaments – keeps the tibia and fibula together at the top.

An Ankle sprain treatment which may involve adjusting the fibula

Pott fracture – common eversion fracture – foots in the dirt and someone lands on the foot causing twisting eversion of the foot - Eversion of the whole foot tightens the deltoid ligament on medial aspect of ankle but it is very strong so wont break so it pulls the bottom of the fibula off and creates an evulsion fracture. Talus and calcaneous go laterally in eversion and this breaks the fibula about a third of the way up.

Bummber or boot top fractures- tibia break about a third of the way down were it the thinnest - Bumber or boot top fractures (height of bumpers and ski boots so foot get stuck ain snow and you leg keeps going and snaps the bone)- Tibia breaks at thinnest part 1/2 of the way down

Most ankle sprains are inversion sprain because the lateral collateral are weaker then the medial collateral.

compartment syndrome –hypertrophying of the muscle in a compartment the muscles to expand and sense the fascia wont stretch they can't go any were so this builds pressure in the compartment and this can impinge nerves and blood vessel. Extreme solution is fasciaotomy were they cut the fascia

Anterior compartments –extensors –

Tom (tibilias anterior) ,

Dick (EDL)

and Harry (hallicus longus) - all dorsi flexors and toe extenders of the foot

Fibularis or peroneus tertiarus – slip of E digitorum

deep peroneol nerve

Anterior tibial artery

Lateral compartments

peroneus or fibularis longus and brevis – everters of the foot and slight/weak plantar flexors

superficial fibula/peroneol nerve

posterior compartment

Superficial posterior

compartments

• Triceps surea
• plantaris

Supplied by the branches of the tibial nerve

• Deep posterior compartments
• Flexors - Tom , Dick and Harry
• Popletieus

Supplied by the branches of the tibial nerve

• Anterior compartment of leg
• Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus, Peroneus tertius

Deep peroneal nerve

• Lateral compartment of leg
• Peroneus longus, Peroneus brevis
• Superficial peroneal nerve

• Deep posterior compartment of leg
• Tibialis posterior, Flexor hallucis longus, Flexor digitorum longus, Popliteus
• Tibial nerve

• Superficial posterior compartment of leg
• Gastrocnemius, Soleus, Plantaris
• Medial sural cutaneous nerve

yes due to peroneus or fibularis longus and brevis – everters of the foot and slight/weak plantar flexors and the fact they innervated by the superficial fibula/peroneol nerve

In a inversion sprain the peroneus brevis attaches onto the base of the first metatarsal , the tendon is stronger then the bone and may break of part of the bone and you should xray both sides of the leg because there are two ossification centers (secondary ossification center) in this bone and this episheal plate can look like a crack or evulsion fracture so you compare the two sides to make sure it is a flake fracture if its the same then in a child its just the secondary ossification center. There wont be a secondary ossification center in an adult.


Can determine age by the epipheseal plates and how much more a person has to grow.

Shins splints (catchall term for pain in the shins) (currently we believe this is caused by the periosteum geting inflamed and cause anterior pain– may be due to posterior tibialis) can be confused with anterior compartment syndrome.

Deep peroneol nerve goes to the anterior compartment of the leg and then across the foot to the web space. Not to be confused with the superficial peroneol nerve which can cover the deep peroneol nerve.

Superfical peroneol nerve is on the top of the foot and the deep peroneol is in the web space.

Anterior tibial artery and deep peroneol nerve runs down past the ankle onto the foot. AS it crosses the ankle the anterior tibial artery becomes the dorsal pedal artery.

dorsalis pedis artery (dorsal artery of foot), is a blood vessel of the lower limb that carries oxygenated blood from the dorsal surface of the foot. It arises at the anterior aspect of the ankle joint and is a continuation of the anterior tibial artery. It terminates at the proximal part of the first intermetatarsal space, where it divides into two branches, the first dorsal metatarsal artery and the deep plantar artery.

he triceps surae (from Latin caput and sura. "three-headed calf [muscle]") is a pair of muscles located at the calf - the gastrocnemius and the soleus. These muscles both insert into the calcaneus, the bone of the heel of the human foot, and form the major part of the muscle of the back part of the lower leg, commonly known as the calf muscle.

• he achilles tendon can take a 1000 lbs of force before it breaks, but does break some times in sprinters and
• when this happens the muscle migrates upward causing it to seem to swell.

Achilles tendonitis – very common site inflammation. Common in athletes and sprinters

In sprinting always land on the dorsiflexed foot. Never point the toe down because you loose time each time you have to push off. So you land on a rigid foot and you pull ground behind you with your heel. This can be very painful when you new to sprinting.

The term Tennis Leg refers to an acute medial head of the gastrocnemius muscle tear in the older athlete characterized by sudden onset of severe calf pain and significant disability. The injury is invariably associated with extensive bruising and swelling, and can be mistaken for a deep venous thrombosis. The most common site is the medial head of gastrocnemius, but occasionally the plantaris muscle is involved. Symptoms are a sudden, sharp or burning pain in the leg, sometimes accompanied by an audible sound. In most cases, the player is unable to continue play because of the severe pain. Depending on the severity of the injury, recovery may take between a few days and six weeks.

Collonus – is the uncontrolled bouncing of a muscle when reflex tested. Is a symptom of upper motor neuron lesion or disease. SO is a CNS problem like spinal injuries strokes or MS.

Upper motor neuron – is a multipolar neuron that goes from the brain to the spinal cord. Were as the lower motor neuron goes from the spinal cord to the muscle. So upper motor neuron lesion means it a CNS issue. Such issue can cause collonus.

Posterior impingement syndrome – posterior process of the talus made of a lateral and medial tubercle which this muscles tendon passes through. Common place of inflammation of flexor hallucis longus - common in people who do a lot of jumping such as soccer players and ballerinas, volley ball players.

Suppination of the foot is made of three movements – inversion, plantar flex, and adduction (or medila rotation) creates supination of the foot.

Pronation of the foot – dorsiflexed, everted, abducted foot

Tarsal tunnel – inflamed bursea and swelling in the tunnel causes rubbing on the tibial nerve running under the reticulum that forms an arch – symptoms burning along the big toe.

Tarsal tunnel syndrome (TTS), also known as posterior tibial neuralgia, is compression neuropathy and a painful foot condition in which the tibial nerve is impinged and compressed as it travels through the tarsal tunnel. TTS is a compression syndrome of the tibial nerve within the tarsal tunnel. This tunnel is found along the inner leg behind the medial malleolus (bump on the inside of the ankle). The posterior tibial artery, tibial nerve, and tendons of the tibialis posterior, flexor digitorum longus, and flexor hallucis longus muscles travel in a bundle along this pathway, through the tarsal tunnel. In the tunnel, the nerve splits into three different paths. One nerve (calcaneal) continues to the heel, the other two (medial and lateral plantar nerves) continue on to the bottom of the foot. The tarsal tunnel is made up of bone on the inside and the flexor retinaculum on the outside. Patients complain typically of numbness in the foot, radiating to the big toe and the first 3 toes, pain, burning, electrical sensations, and tingling over the base of the foot and the heel. Depending on the area of entrapment, other areas can be affected. If the entrapment is high, the entire foot can be affected as varying branches of the tibial nerve can become involved. Ankle pain is also present in patients who have high level entrapments. Inflammation or swelling can occur within this tunnel for a number of reasons. The flexor retinaculum has a limited ability to stretch, so increased pressure will eventually cause compression on the nerve within the tunnel. As pressure increases on the nerves, the blood flow decreases.Nerves respond with altered sensations like tingling and numbness. Fluid collects in the foot when standing and walking and this makes the condition worse. As small muscles lose their nerve supply they can create a cramping feeling.

Pes planus – technical term for flat foot


Pes cavus – foot cave or very arched foot – caused by genetics

The sesamoid bones of the first toe create an arch way to prevent the tendon of flexor hallucis longus and brevis to prevent them from being crushed by the foot over and over again.

hallicus rigidus –common with diabetics can't flex big toe well , which may cause pressure build up and sores devolope there that they can't feel anything in the feet (due to the diabetes) and this can lead to infection and amputations.

• Posterior tibial artery supplies the
• back of the leg (deep compartment)

• Deep tibial nerve innervates the
• posterior deep compartment.

fibular (peroneol) artery – goes down lateral compartment which it supplies.

Lateral compartment is innervated by the superficial peroneol nerve.

Medial plantar nerve goes to the big toe. Tarsal tunnel syndrome can effect this and cause big toe symptoms.

Lateral plantar nerve goes to the rest.

stretch the gastroc and not soleus – you keep the knee straight and ankle dorsiflexed you strect the gastronemius but if you bend the knee it stretches the soleus only, because the gastronemus is on slack