MSK compartments of the thigh Flashcards
S4.the knee. includes conditions of knee SM
what are the borders of the femoral triangle?
pectineus- base
sartorius- lateral border
adductor longus - medial border
inguinal ligament - superior border
Actions of anterior thigh muscles?
innervation?
Rectus femoris Vastus medialis/intermedius/lateralis sartorius pectinous - obturator iliopsoas - psoas major= anterior rami
> femoral nerve
- EXTEND the knee joint (except sartorius and pectineus)
pectineus-adducts and flexes thigh at hip joint
sartorius- flexes, abducts, externally rotates thigh at hip joint.
flexes and internally rotates tibia at knee joint
Actions of posterior thigh muscles?
innervation?
biceps femoris- flexes knee joint
semitend/membranosus - flexes leg at knee (also extends hip)
tibial branch of sciatic nerve
(short head of biceps femoris is common peroneal/ fibular)
Actions of medial thigh muscles?
innervation?
Adductor Magnus/brevis/ longus
Pectineus
Obturator Externus
Gracillus
> obturator nerve (but hamstring part of adductor Magnus is tibial branch of sciatic nerve)
ADDUCTORS
what is the origin of all adductor muscles?
pubis
actions of Sartorius?
flexes, abducts and laterally rotates the hip joint and flexes the knee joint’.
contrary to the other anterior compartment muscles (rectus femoris and vests triplets) which extend the knee joint.
which bones articulate to form the knee joint?
patella
femur
tibia
what does the tibiofemoral articulation consist of?
medial and lateral condyles of femur articulating with the tibia
what does the patellofemoral articulation consist of?
anterior part of distal femur articulating with patella
roles of the patella?
- protection from trauma
- increases mechanical efficiency of quadriceps femoris muscle by minimising friction and allowing tendon to go directly over anterior surface of knee
what is hiltons law?
all muscles that cross a joint supply the joint itself (nerve)
which nerves supply knee joint?
Femoral nerve, tibial nerve, common peroneal (fibular) nerve
What are the two main functions of the menisci in the knee?
- To deepen the articulating surface of the tibia, thereby increasing stability of the joint
- To act as shock absorbers by increasing area to further dissipate forces
Which is the main stabiliser of a weight-bearing flexed knee?
The PCL
prevents the femur from sliding off the anterior edge of the tibia e.g. when walking down stairs or down a slope.
what is the attachments of ACL?
ACL attaches proximally to the posterolateral aspect of the femoral intercondylar fossa
passes distally and anteromedially to attach to the anterior aspect of the intercondylar eminence of the tibia,
also attaches to medial meniscus
what is the attachments of PCL?
PCL attaches proximally to the medial border and roof of the intercondylar fossa.
passes distally and posterolaterally to attach to the posterior intercondylar area of the tibia.
which muscles do flexion at the knee joint?
nerve supply?
posterior muscles of thigh:- biceps femoris semitendinosus semimembranosus > tibial nerve
gracilis (medial thigh)
> obturator nerve
sartorius (anterior thigh)
> femoral nerve
gastrocnemius
plantaris
popliteus
> tibial nerve
which muscles do extension at the knee joint?
nerve supply?
quadriceps femoris (its 4 components)
> femoral nerve
which muscles do lateral rotation at the knee joint?
nerve supply?
Biceps femoris
> tibial nerve
which muscles do medial rotation at the knee joint?
nerve supply?
Popliteus
Semimembranosus
Semitendinosus
> tibial nerve
Gracilis > obturator nerve
Sartorius > femoral nerve
whats the typical mechanism of injury in patella dislocation?
movement?
trauma
- twisting injury/ direct blow to knee
internal rotation of femur on a planted foot while flexing the knee (e.g. sudden changing direction in sports)
symptoms of septic arthritis?
pain
fever
reduced range of motion
most common joint for septic arthritis?
common pathogen?
knee
staphlococcus aureus
pain characteristics of osteoarthritis in knee?
- wose when sitting for long periods/ getting out of bed in morning.
- intermittent Knee pain (comes and goes), > chronic low level of pain punctuated by more severe flare-ups
- Pain precipitated by bending, kneeling, squatting or climbing stairs
Why do some patients with osteoarthritis of the knee describe their knee giving way or buckling?
painful stiff knee > move the joint less >muscle weakness (quadriceps muscles) > instability of the joint.
Quadriceps weakness : reduced power of knee extension, and therefore the patient experiences sudden flexion (‘giving way’) of their knee.
In a collateral ligament tear, if there is a medial angulation of the distal segment, which type of deformation exists?
varus deformity,
because the tibial plateau sits medially to where it should be.
what is varus and what is valgus?
Whenever the distal part is more lateral, it is called VALGUS.
(Gum sticking knees together)- like need a wee
… Whenever the distal part is more medial, it is called VARUS.
knees pointing out
(Rum pushing knees apart)
Which test would be used for a posterior cruciate ligament tear?
The drawer test
Which structures are damaged in the Unhappy triad?
damage to the medial meniscus, anterior cruciate ligament and medial collateral ligament.
-caused by a direct blow to the lateral side of the knee.
The inability to perform a straight leg raise is a clinical indication of which condition?
fracture to the patella.
> quadriceps tendon attaches to the patella, and so with the patella in pieces it cannot be used as an attachment.
A blow to the back of the knee is more likely to cause…
damage to the ACL,
> ligament furthest from the site of force, so is the ligament put under more pressure.
A popping sensation is commonly felt when you damage your…
Cruciate ligaments
What is the technical name for ‘Clergyman’s knee’?
infra-patellar bursitis,
caused commonly by irritation to the front of the knee (typically by kneeling).
What is the technical name for ‘Housemaids knee’?
pre patella bursitis
What is Supra patella bursitis?
knee joint effusion
What is Semi membranous bursitis?
popliteal (Bakers) cyst
The lateral cutaneous nerve pierces which ligament?
inguinal ligament
Which muscle contributes to the abduction of the proximal fragment of a femoral shaft fracture?
Gluteus medius
responsible for the abduction of the proximal fragment of the femur.
The burning/stinging sensation felt in meralgia paresthetica is located over which aspect of the thigh?
lateral thigh,
because this is the area of sensory innervation of the lateral cutaneous nerve.
(see S6)
