Session 7: The Knee, Leg, Ankle and Foot (24.01.2020) Flashcards
What are the bones of the region?
The femur The tibia The fibula The patella The bones of the foot
What is the leg?
between the knee and the ankle
What is between the 2 parallel bones?
-> tibia and fibule
In-between them is an interosseous membrane
What are the joints in that region?
- knee joint
- ankle
What attaches to the tibial tuberosity?
patellar tendon
Which tarsal bone connects with the
Talus
Which tarsal bone connects with the tibia and fibula?
Talus
What are the muscle compartments of the region?
Anterior compartment of the leg
Lateral compartment of the leg
Posterior compartment of the leg
Intrinsic muscles of the foot
Sole – 4 layers
Dorsum – 2 muscles
-> also considering the anterior compartment if the thigh as the muscles act across the knee joint
What are the muscle compartments of the region?
- Anterior compartment of the leg
- Lateral compartment of the leg
- Posterior compartment of the leg
Intrinsic muscles of the foot
- Sole – 4 layers - Dorsum – 2 muscles
-> also considering the anterior compartment if the thigh as the muscles act across the knee joint
The Anterior Compartment of the Thigh
-> flexors and knee extensors
(Pectineus
Ilio-psoas) -> do not act across the kenn joint
Tensor fasciae latae Sartorius Quadriceps femoris - Rectus femoris - Vastus medialis - Vastus intermedius - Vastus lateralis -> act across the knee joint
Which muscle from the medial compartment of the thigh acts across the knee?
Gracilis
-> stability of the knee
(The action of the muscles of the medial compartment of the thigh is adduction. These muscles include: Adductor longus Adductor brevis Adductor magnus Gracilis (acts across the knee joint) Obturator internus)
Which muscles are in the anterior compartment of the leg? What is their function, innervation and BS?
- > Ankle Dorsiflexors (extensors)
- > Deep Peroneal Nerve
- > Anterior Tibial Artery
- Tibialis Anterior
- Extensor Digitorum Longus
- Extensor hallucis Longus
x
Anterior compartment muscles extend (dorsiflex) the foot at the ankle joint and extend the digits. Supplied by the deep branch of the peroneal nerve.
Lateral compartment muscles evert the foot and can contribute to dorsiflexion.
Anterior vs. lateral compartments of the foot (function and innervation.
Anterior compartment muscles extend (dorsiflex) the foot at the ankle joint and extend the digits. Supplied by the deep branch of the peroneal nerve.
Lateral compartment muscles evert the foot and can contribute to dorsiflexion. Supplied by the superficial peroneal nerve (L5,S1,S2)
Which muscles are in the posterior compartment of the leg? What is their function, innervation and BS?
- > Ankle Plantarflexors
- > Tibial nerve
- > Posterior Tibial Artery
Superficial
- Gastrocnemius
- Soleus
- Plantaris
Deep
- Popliteus (associated with the knee)
- Flexor Digitorum Longus
- Flexor Hallucis Longus
- Tibialis Posterior
Polipiteal fossa - what are the boundaries and contents?
- region behind the knee joint. The diamond-shaped space posterior to the knee-joint.
Boundaries
- Biceps Femoris
- Semimembranosus
- Lateral head of gastrocnemius
- Medial head of gastrocnemius
- Skin and fascia
- Femur
Contains
- Popliteal artery and vein
- Tibial Nerve and Common Peroneal Nerve
- Short saphenous vein
- Popliteal lymph nodes
What is the largest joint in the body?
Knee joint
The Knee Joint
- Largest joint; superficial; primarily a hinge-type synovial joint with some gliding, rolling and rotation.
- The shapes of the bones involved (distal femur and proximal tibia) do not predict a stable arrangement.
- stabilised by muscles and ligaments (e.g. anterior and posterior cruciate ligaments, and medial and lateral collateral ligaments)
- meniski: cartilages, can get damaged
What are the anatomical similarities of the hand and foot?
- tarsals = carpals
- metatarsals = metacarpals
- phalanges = phalanages
- digits have 3 phalanges apart from thumb/hallux which has 2
What is the role of the 2 sesamoid bones in the foot?
- prevent crushing of a tendon that lies between them: flexor hallucinations longus
What are the arches in the foot?
- transverse
- transverse longitudinal
- medial longitudinal
- longitudinal are formed between the calcaneus and the heads of the metatarsals)
- Flat feet - locomotion is reduced!
- Ligaments and long tendons are both involved. Long tendons and intrinsic muscles also support the arches.
Plantar Aponeurosis
=> the bones of the foot do not lie in a horizontal plane and form longitudinal and transverse arches in relation to the ground.
Heel bone
calcaneus
Which bones are part of the ankle joint?
- fibula
- tibia
- talus
Gracilis muscle
- runs medially along the thigh
- attaches to the inferior ramus of the pubis and inferiorly to the tibia
- stabilises the knee joint.
Which muscles from the posterior compartment of the thigh act across the knee joint? What is their function?
- semimembranosus
- semitendinosus
- biceps femoris
= hamstrings -> knee flexors and hip extensors)
What is the function of the muscles in the anterior compartment of the leg?
collectively they:
- dorsiflex the foot at the ankle joint
- extend toes
- invert the foot
Tibialis anterior
- most anterior and medial muscle of the anterior compartment of the leg
Attachments:
- lateral surface of tibia and adjacent interosseous membrane
- medial and inferior surfaces of medial cuneiform form and adjacent surfaces on base of metatarsal I
- muscle fibers converge and form a tendon at the lower 1/3 of the leg to form a tendon.
Innervation:
- deep fibular nerve (L5,S1)
Fucniton:
- dorsiflexion of the foot at the ankle joint
- inversion of the foot
- dynamic support of medial arch of foot
Which nerve innervates the anterior compartment of the leg?
deep fibular nerve (L4,5, S1)
What is the difference between fibularis and peroneus?
There is no difference, they are the same muscles (lateral compartment of the leg)
- peroneus is the term used in the UK
- fibularis is the term used in the USA
Which nerve innervates the muscles in the lateral compartment of the thigh?
The superficial peroneal nerve (this is a branch of the common fibular nerve)
What is the innervation and arterial blood supply of the muscles in the posterior compartment of the leg?
- tibial nerve
- posterior tibial artery
Which muscles form the achilles tendon?
- soleus and gastrocnemius (the fibers converge in the lower leg to form the achilles (=calcaneal) tendon which attaches to the heel (=calcaneus) of the foot.
Triceps surae
Gastrocnemius (2 heads) and Soleus (1 head) together form Triceps Surae whose distal tendon is tendocalcaneus (Achilles tendon).
Why is the polpiteus an important muscle?
- it is the smallest and most superior muscle of the posterior compartment of the leg
- it unlocks the extended knee at the initiation of flexion and stabilises the knee by resting lateral (external) rotation of the tibia on the femur.
- flat and triangular in shape
Attachments:
- lateral femoral condyle
- posterior surface of proximal tibia
Innervation: tibial nerve (L4 to S1)
What Is the role of foot muscles?
- For most people, the intrinsic muscles of the foot function generally act as SCHOCK ABSORBERS, adjusting the foot to uneven surfaces.
- even floors are quite new to use (evolution wise)
- Feet can be “trained” for carrying out fine movements, such as writing and drawing. Individuals lacking upper limbs are able to use their feet to carry out a variety of fine activities.
What are the muscles in the different layers in the sole of the foot?
Layer 1:
- abductor hallucis
- flexor digitorum brevis
- abductor digiti minimi
Layer 2:
- quadrates plantae
- lumbricals
Layer 3:
- flexor hallucis brevis
- adductor hallucis
- flexor digiti minimi brevis
Layer 4:
- dorsal interossei
- planter interossei
Name a muscle in the foot that does not have an equivalent in the hand
quadrates plantae
What are the ligaments of the knee joint?
- Anterior cruciate ligament
- Posterior cruciate ligament
- Medial collateral ligament
- Lateral Collateral Ligament
Locking mechanism of the knee
- When standing, the knee joint is locked into position thereby reducing the amount of muscle work needed to maintain the standing position
- the joint surfaces are larger and more stable in extension
- medial rotation and full extension tightens all the associated ligaments (another component of the locking)
- the popliteus muscle unlocks the knee by initiating lateral rotation of the femur on the tibia
Muscles in the extensor mechanism of the knee:
- Quadriceps
- Quadriceps tendon
- Patella
- Patellar ligament
- Tibial tuberosity
What are the muscles in the extensor mechanism of the knee?
Quadriceps Quadriceps tendon Patella Patellar ligament Tibial tuberosity
What are menisci? What are the names of the menisci in the knee joint?
They are fibrocartilagenous C-shaped cartilages in the knee joint.
- medial and lateral meniscus
Names of the bursae at the knee joint?
Pre-patellar bursa infrapatellar bursa suprapatellar bursa Popliteal bursa ... -> there are more bursae in the knee
bursa = little synovial sac
Cruciate ligaments
Anterio cruciate ligament:
- attaches to a facet on the anterior part of the intercondylar area of the tibia and ascends posteriorly to attach to a facet at the back of the lateral wall of the intercondylar fossa of the femur. (A tibia L femur)
- prevents anterior displacement of the tibia relative to the femur
Posterior Cruciate Ligament:
- attaches to the posterior aspect of the intercondylar area of the tibia and ascends anteriorly to attach to the medial wall of the intercondylar fossa of the femur. (P tibia M femur)
- prevents posterior displacement of the tibia relative to the femur.
Collateral ligaments
- medial and lateral OR tibial and fibular
- medial: attached to medial femoral epicondyle just inferior to the adductor tubercle and descends anteriorly to attach to the medial margin and medial surface of the tibia above and behind the attachment of sartorius, gracilis and semitendinosus tendon.
Note the attachment between medial meniscus and the medial ligament - lateral collateral ligament/fibular ligament: attached superiorly to the lateral femoral epicondyle and inferiorly to a depression on the lateral surface of the fibular head. separated from fibrous membrane by a bursa.
Bursitis
- inflammation of the bursa
- very painful
Apart from the knee joint, what are the other joints in that region?
- Proximal and Distal Tibio-Fibular Joints
- Ankle Joint
- Subtalar Joint
- Midtarsal Joint
- Metatarso-phalangeal joints
- Interphalangeal Joints
What is a way to identify where a blockage is in the leg?
- test pulses
- if you feel one and don’t feel the one distal to that it means that the blockage is somewhere in-between.
Tibiofibular joints
Proximal Tibiofibular Joint:
- is plane type synovial, but capsular ligaments limit movement.
Distal Tibiofibular Joint:
- is a fibrous joint.
- Slight movement of both of these joints during dorsiflexion/plantarflexion of the foot.
The collateral ligaments of the ankle joint
- (sprained ankles)
- The broader and tougher tibiocalcaneal ligament is less often damaged. This ligament is also called the deltoid ligament.
- The lateral ligaments (3 parts) are commonly damaged by OVER-INVERSION.
- posterior talofibular ligament
- anterior talofibular ligament
- calcaneofibular ligement
Weight bearing at the ankle joint
- The weight-bearing at the ankle joint is by talus via it’s superior articulation with tibia.
- Fibula is not weight-bearing, but it’s distal lateral malleolus, with tibia’s medial malleolus, forms the square socket of the ankle joint.
- talus sits on top of calcaneus
The talo-calcaneonavicular joint
- The talo-calcaneonavicular joint is part of the transverse tarsal joint or the mid-tarsal joint.
- Movement at this joint contributes to inversion and eversion of the foot together with movement of the subtalar joint.
Gait Cycle - not taught in lecture (look over it at some point before exams)
x
Arteries of the region
Arteries
- External iliac artery
- Femoral artery – midinguinal point
- Femoral artery lies between the femoral vein (medial) and the femoral nerve (lateral)
- Profunda femoris artery
- Circumflex vessels
- Femoral artery continues as the superficial femoral artery and subsequently as the popliteal artery
Popliteal artery- genicular (knee) branches
Popliteal “Trifurcation”
- Anterior tibial artery : anterior compartment
- Posterior tibial artery : posterior compartment
- Peroneal artery : lateral compartment
At the ankle
- Posterior Tibial Artery : sole of the foot via the medial and lateral plantar arteries
- Dorsalis pedis artery (continuation of the anterior tibial artery) and supplies the dorsum of the foot and the digits
When does the femoral artery become the popliteal artery?
x
Venous Drainage of the region
Superficial veins
- Dorsal venous arch
- Long saphenous vein
- Short saphenous vein
- Perforating veins to the deep system (mainly in the calf)
- Valves!
Deep veins
- Deep calf veins – venae comitantes of arteries
- Popliteal vein
- Femoral vein
- External iliac vein
- Sapheno-femoral junction
- Venae comitantes of the profunda femoris artery
The dorsal arch gives off 2 veins: the great/long and small/short saphenous vein.
Motor segmental supply of the region?
Hip Flexors
- L23
Hip Extensors
- L45
Knee Extensors
- L34
Knee Flexors
- L5S1
Ankle Dorsiflexors
- L45
Ankle Plantarflexors
- S12
Sensory segmental supply
Dermatomal distribution
- “L3 to the knee and L4 to the floor”
- L5 to the great toe
- S1 to the lateral side of the foot
- S1 to the sole of the foot
Motor peripheral supply
- Femoral nerve : Knee Extensors
- Sciatic Nerve : Hamstrings
- Tibial nerve : Posterior Compartment and Foot intrinsics
Common Peroneal Nerve : Anterior and Lateral Compartments
The Sciatic nerve
- Passes from pelvis to buttock via greater sciatic notch/foramen
- In the buttock lies in the inferior and medial quadrant
- Passes along posterior aspect of the thigh
- Divides into the tibial nerve and the common peroneal nerve inconstantly
- Supplies all the hamstring muscles and all the muscles below the level of the knee
- If injecting in the buttock, use the superior and lateral quadrant
Tibial nerve
- Posterior Compartment of the Leg
- Passes behind medial malleolus to divide into:
- Medial plantar nerve
- Lateral plantar nerve
- All intrinsics except extensor digitorum brevis
Common Peroneal Nerve
- Winds around the neck of the fibula
- Deep Peroneal Nerve: anterior compartment
- Superficial Peroneal nerve: lateral compartment
Sural Nerve
The Sural nerve is formed from a branch of the tibial nerve and a smaller branch from the common peroneal nerve.
Can be used in nerve repair.
Sensory peripheral supply
- Sensory branches of the femoral nerve
- Saphenous nerve (femoral)
- Sural nerve (common peroneal and tibial)
- Superficial Peroneal nerve
- Deep Peroneal nerve
- Tibial nerve
- Medial and lateral plantar nerves
