Lower Limb Flashcards
What is the blood supply to the lower limb?
External iliac artery
Femoral artery
Profunda femoris
At what point does the external iliac artery become the femoral artery?
when the external iliac crosses the inguinal ligament
What vessels supply the gluteal region?
superior and inferior gulteal artery
they both come off the internal iliac artery
At what point does the femoral artery become the popliteal artery?
when the femoral artery passes throgh the adductor canal and the adductor hiatus above the knee. The popliteal artery then branches into the anterior and posterior tibial artery
What are varicose veins?
This is when veins become enlarged and tortous (twisted). The valves do not work (valvular incompetence) and this allows blood to flow backwards causing the veins to enlarge even more. Varicose veins are most common in superficial veins
Where does the lumbar plexus arise from?
L1-L4
Where does the sacral plexus arise from?
L4-5, S1-S4
What arteries supply the head and neck of the femur?
Medial and lateral circumflex artery which comes off the profunda femoris, the retinacular arteries, and the accetabular branch of the obturator artery
What is the name of the fascia that surrounds the thigh and leg?
Thigh - fascia lata and intermuscular septa
Leg - crural fascia and interosseus membrane
What muscles are found in the anterior compartment of the thigh?
Quadriceps femoris
Pectineus
Sartorius
Ilopsoas
What are the actions of the muscles in the anterior compartment of the thigh?
Flexors of the hip and extensors of the thigh
Rectus femoris stabilises the hip joint
Iliopsoas is a major flexor of the hip
Pectineus and Sartorius - adduction and lateral rotation
What nerve supplies the anterior compartment of the thigh?
Femoral nerve
L2,3,4
It descends under the inguinal ligament and onto the anteror surface of psoas
What muscles are found in the medial compartment of the thigh?
Adductors (gracilis and obturator externus)
What nerve supplies the medial compartment of the thigh?
Obturator nerve
L2,3,4
What muscles are found in the posterior compartment of the thigh?
Hamstrings
Extensors of the hip and flexors of the knee
What nerve supplies the posterior compartment of the thigh?
Tibial divison of sciatic nerve
L5, S1, S2
What are the contents of the femoral triangle?
N- femoral nerve A - femoral artery V - femoral vein E - empty space L - deep inguinal lymph nodes and lymphatic vessels (lateral to medial)
What are the boundaries of the femoral triangle?
superior - inguinal ligament
medial - medial border of adductor longus
lateral - medial border of sartorius
What is the clinical relavence of the femoral triangle?
femoral pulse and cannulation of the femoral artery and vein
Where is the midpoint of the inguinal ligament and what is its clinical relavence?
Midway between the ASIS and pubic tubercle
The femoral pulse is inferior to the midpoint of the inguinal ligament
Where is the mid-inguinal point?
Midway between the ASIS and pubic symphysis
What is the Q angle of the knee?
Q angle is the angle formed by a line drawn from the ASIS to central patella and a second line drawn from central patella to tibial tubercle.
Approx 14 degress for males, and 17 degress for females
If Q angle is increased, this identifies: genus valguma and patella subluxation
What is the menisci of the knee?
crescent shaped fibrocartilaginous discs between femoral and tibial condyles
It turns the tibial plateau into a cup shape.
It is thicker on the outside and thinner on the inside
The medial menisci is larger than the lateral menisci. It attaches to the medial collateral ligmant and the anterior cruciate ligament
What happens to the knee during extension?
Lateral condyle lock in first. There is still more room for the medial condyle. Additional movement of the medial rotation causes the knee to twist. This locks the knee in
What are the 3 articulations of the knee joint?
lateral femoral and tibial condyles with corresponding meniscus
medial femoral and tibial condyles with corresponidng meniscus
patella and femur
What is a bursa?
extensions of the knee synovial cavity and are filled with synovial fluid
cushions against friction and rubbing of tendons, ligaments and bones around the knee joint
What is articularis genu?
Small flat muscles from vastus intermedius attach to femur and suprapatellar bursa
keeps synovial membrane from being trapped between patella and femur
keeps bursa safe and stops it dropping between the femur and patella
What is a baker’s cyst?
May form from a normal bursa or herniation of the joint capsule.
Often associated with meniscal tears
Or degenerative arthritis of the knee.
What are the articular ligaments?
medial and lateral collateral ligaments
anterior and posterior cruciate ligaments
patella ligament
articular capsule
what is the function of the lateral collateral ligament?
Strong fibrous cord.
Not attached to joint capsule or lateral meniscus.
Taut in knee extension -prevents knee adduction
What is the function of the medial collateral ligament?
Broad flat ligament
Thickening of joint capsule, attached to medial meniscus.
Taut in knee extension - prevents knee abduction
What is the function of the anterior cruciate ligament?
lateral femoral condyle to anterior intercondylar area of tibia
Stops tibia moving forward on femur
Stabilise knee in extension and prevents hyperextension and excessive internal rotation
What is the function of the posterior cruciate ligament?
medial femoral condyle to posterior intercondylar area on tibia
not connected to collaterals or menisci
Stops tibia moving backward on femur.
Stronger than the ACL
Helps stabilise knee especially in flexion
Also prevents tibia twisting outward (external rotation)
What is the ‘unhappy triad’?
The triad refers to a complete or partial tear of the anterior cruciate ligament, medial collateral ligament, and the meniscus.
What type of bone is the patella bone?
seasmoid bone embedded in tendon and ligament
Where does the patella ligament arise from and what is its function?
continuation of the quadriceps femoris muscle tendon located in the anterior thigh
prevents forward movement of tibia on femur
What muscles are found in the anterior compartment of the leg and what nerve supplies it?
Dorsiflexors: Tibialis anterior, extensors (extensor digtorium longus and extensor hallucis longus)
supplied by the deep branch of the common peroneal nerve ( L4,5)
Function: dorsiflex ankle, invert foot and extend toes
What muscles are found in the lateral compartment of the leg and what nerve supplies it?
Peroneal muscles (fibularis longus and fibularis brevis)
supplied by the superficial branch of the common peroneal nerve (L5, S1, S2)
Function: Evertion and plantarflexion
What muscles are found in the posterior compartment of the leg and what nerve supplies it?
calf muscles (gastronemius, soleus, plantaris)
supplied by the tibial nerve (S1,2)
Function: plantarfexion
deep calf muscles (tibialis posterior, flexor digitorium longus, flexor hallucis longus)
supplied by the tibial nerve (L4-S3)
Function: flex ankle/ toes
What arteries supply the different compartments of the leg?
Anterior - anterior tibial artery
Lateral - perforating branches of deep fibular
Posterior - posterior tibial artery
What does a common peroneal nerve injury lead to?
Foot drop
Which superficial muscles attach via calcaneal tendon?
gastronemius, solleus and plantaris
What is the function of the deltoid ligament of the ankle?
supports medial side of the ankle joint
Very strong, stabilise ankle joint during eversion and prevent subluxation
What are the lateral ligaments of the ankle?
anterior talofibular
posterior talofibular
calcaneofibular
What is an inversion injury?
sprained ankle
damage to the anteror talofibular and calcaneofibular ligament
2/3 of lateral ligaments are torn
Treatment: RICE
What is the largest and strongest tendon in the lower limb?
calcaneal tendon
Describe the medial longitudinal arch of the foot
Arch tall = medial side of foot missing from footprint.
Resilient due to large number of bone components
Describe the lateral longitudinal arch of the foot
Flatter as fewer bones and talus transmits body weight
through it.
What structures pass under the flexor retinacula?
tibial nerve and posterior tibial artery
What structures pass under the extensor retinacula?
deep peroneal nerve and anterior tibial artery
Explain the maintenance of the longitudinal arches
muscle tendons that insert into apex of arches tend to increase their height e.g tibialis anterior
muslce tendons that run through the sole of the foot prevent separation e.g fibularis longus
shape of the bones allow them to interlock
longitudinally arranged ligaments prevent separation e.g long and short plantar ligaments (lateral side of foot) and the plantar calcaneonavicular (spring) ligament (medial side of foot)
What do the following dermatomes correspond to?
a) L1
b) L2
c) L3
d) L4
e) L5
f) S1
a) inguinal region
b) thigh
c) medial knee
d) medial leg
e) lateral leg and big toe
f) little toe
