Knee and posterior leg Flashcards
what are the articulations of the knee joint
- femoral condyles to the tibial plateuas
- patellar surface of femur with patella
Joint capsule of the knee
- surrounds the knee
- fibrous layer (dense CT) with a synovial membrane (loose CT to secrete synovial fluid)
- function: seals joint space, stability aids in function of the joint
Ligaments of the knee
- patellar ligament
- medical collateral ligament
- lateral collarteral ligament
- anterior cruciate ligament
- posterior cruciate ligament
Patellar ligament
- runs form patella to the tibial tubercle
- continuation of the quadricepts tendon inferiorly to the patella
LCL
- runs from the lateral epicondyle of the femur to the fibular head
MCL
- runs from the medial femoral condyle to the medial surface of the tibia
ACL
- runs from anterior intercondylar area of the tibia to the posterior lateraly condyle of the femur
- extended knee = taut
- prevents anterior translation of tibia on femur (open chain)
- prevents posterior translation of the femur on the tibia
APEX
PCL
- runs from the posterior intercondylar tibia to the anterior medial condyle of femur
- flexed = taut
- prevents posterior translation of the tibia on the femur
- prevents anterior translation of the femur on the tibia
Menisci
- fibrocartilaginous ring that cushions the femoral condyles to dissipate forces
- function: shock absorption, congruence, increase contact area, reduce frition, lubricate nutrition, joint proprioception
- during extension = move anterior
- during flexion = moves posterior
- during rotation = moves opposite tibial plateau
- blood supply :red zone = outter zone and white zone = less blood supply
Lateral meniscus
- circular
- more motion than medial
- attaches to the popliteus, coronary ligaments
- not the LCL
Medial meniscus
- thinner than lateral
- attaches to the MCL
- C-shaped
- less motion
Bursae of the knee
extensions of the capsule:
- suprapatellar: above patella
- subpopliteal: under popliteus
- gastrocnemius: b/w the medial head of the gastroc and semimembranosus tendon
Independent bursa:
- prepatellar in front of patella
- infrapatella: nder the patellar tendon
- deep infrapatellar: posterior to the distal portion of the patellar tendon
Gastrocnemius
Origin:
1. medial and lateral condyles
Insertion:
1. calcaneus
Action:
1. knee flexion
2. planterflexion
Innervation:
1. tibial nerve S1-S2
Soleus
Origin:
1. poximal posterior tibia
2. proximal posterior fibula
Insertion:
1. calcaneus
Action:
1. Plantarflexion
Innervation:
1. tibial S1-S2
Plantaris
Origin:
1. posterior distal shaft of femur
Insertion:
1. calcaneus
Action:
1. knee flexion
2. ankle plantarflexion
Innervation:
1. tibial S1-S2
popliteus
Origin:
1. posterior tibia
Insertion:
1. Lateral femoral condyle
Action:
1. medially rotates tibia to unlock knee
Innervation:
1.Tibial L4-S1
Flexor hallucis longus
Origin:
1. posterior fibula
2. interosseous membrane
Insertion:
1. distal phalanx of toe #1
Action:
1. flexes great toe
2. plantarflexion of the foot
3. inverts the foot
Innervation:
1. tibial nerve L5-S2
Flexor digitorum longus (foot
Origin:
1. posterior middle tibia
Insertion:
1. distal phalanges of toes 2-5
Action:
1. action flexion of toes 2-5
2. plantarflexion of foot
3. inversion of foot
Innervation
1. tibial L5-S2
Tibialis posterior
Origin:
1. posterior tibia
2. posterior fibula
3. interosseous membrane
Insertion:
1. calcaneus
2. navicular
3. cuboid
4. metatarsals 2-4
5. cuneiforms
Action:
1. plantarflexion of foot
2. inversion of foot
Innervation:
1. tibial nerve L5-S1
Arteries of the posterior leg
- femoral artery runs through the adductor hiatus and becomes popliteal
- runs through head of gastroc
- dives deep to soleus
- divides into posterior tibial and anterior tibial artery
- posterior tibial: through deep region of posterior compartment and behind medial malleolus
- anterior tibial artery runs anteriorly through the interosseous membrane
nerves of the posterior leg
- sciatic nerve runs down the posterior thigh
- branches into the tibial and common peroneal nerve at popliteal fossa
- tibial nerve runs through the heads of the gastroc and under tendinous arch
- tibial nerve supplies innervation to the posterior leg musculature
- continutes to run down the posterior compartment and behind the medial malleolus to the foot
- sural nerve is a branch off the tibial nerve that supplies cutaneous innervation to the posterolateral portion of the leg and foot
Posterior compartment syndrome
types:
- acute: requires medical attention due to bleeding into a compartment
- chronic: exertional due to muscle swelling that results in them being too large for the sheath that surrounds them
chronic stop and rest once symptoms come n and then eventually they should be able to go longer without symptoms
- can also provide with STM and myofascial release
tibial nerve entrapment
- uncommon type of entrapment due to the nerve’s deep path of travel and strong protective tissue
- causes include: posterior compartment syndrome and soleal sling
- tibial branches into medial and lateral plnatar nerve, medial calcaneal nerve and sural nerve
