Posterior Compartment Of Thigh, Popliteal Fossa, Knee Joint, Osteology Of Leg And Foot

Question 1

Muscles of Posterior Compartment of the Thigh

Principles

Answer 1

The “Hamstrings”
From ischial tuberosity to tibial condyles; head of fibula
Extend the thigh and flex the leg

Question 2

Semitendinosus

Posterior Thigh

Answer 2

Prox: ischial tuberosity
Distal: medial part of the proximal tibia
Innervation: Tibial division of the sciatic nerve
Actions: extend thigh; flex and medially rotate the leg

Question 3

Semimembranosus

Posterior Thigh

Answer 3

Prox: ischial tuberosity
Distal: medial condyle of the tibia
Innervation: Tibial division of the sciatic nerve
Action: extend thigh; flex and medially rotate the leg

Question 4

Biceps femoris

Posterior Thigh

Answer 4

Prox: long head-ischial tuberosity
Short head-linea aspera
Distal: Head of fibula
Innervation: Long head-tibial division of sciatic nerve
Short head-common Fibular division of the sciatic nerve
Action: extend the thigh; flex and laterally rotates the leg

Question 5

Sciatic Nerve (L4, 5, S1, 2, 3)

Answer 5

Nerve supply to the posterior compartment of the thigh

Question 6

Posterior Femoral Cutaneous Nerve

S1, 2, 3

Answer 6

Innervates the skin of the posterior thigh (medial to sciatic nerve)
passes deep to the fascia lata
Innervates skin over the popliteal fossa too

Question 7

Blood Supply to the Muscles of the Posterior Thigh

Answer 7

Superior Gluteal Artery (Gluteus Maximus/Medius/Minimus)
Inferior Gluteal Artery (Gluteus Maximus)
Internal Pudendal Artery ?
Perforating Arteries (of the profunda femoral artery) enter the posterior compartment and provide muscular branches to the hamstrings (travel within adductor magnus and brevis)

Question 8

Bursa and Clinical Significance

Answer 8

Bursa: synovial fluid filled sac that helps to reduce the friction btwn bone and a muscle or a bone and a tendon

Clinical Significance: Infection or irritation of a bursa can lead to and inflammation of the bursa “bursitis”

Question 9

Pew Anserinus
(anatomic name of 3 conjoined tendons on medial aspect of the  knee)

Answer 9

From anterior to Posterior: sartorius, gracilis and semitendinosus
Clinic: bursa lies btwn pets anserinus tendons and the more deeply located semimembranosus tendon; bursa can become inflamed and symptomatic (pes anserinus bursitis)
Pneumonic: SGT FOT

Question 10

Adductor Magnus

Answer 10

Prox: adductor part-ischiopubis ramus [pubofemoral portion]
Hamstring part-ischial tuberosity [ischiocondylar portion]
Distal: adductor part-shaft of femur
Hamstring part-adductor tubercle of femur
Innervation: A-obturator nerve
H-tibial division of sciatic nerve
Actions: A: adducts/flexes thigh
H: adducts/extends thigh

Question 11

Articulations between femur and tibia

Answer 11

condyles of femur (with tibial plateus)
Condyles of tibia and cartilaginous menisci
Femur and patella

Question 12

Capsule of the Knee Joint

Answer 12

Extends from femur to tibia
Strengthened by fibers from the:
-fascia lata
-Iliotibial tract
-tendons of the vasti, hamstrings and Sartorius muscles

Question 13

Patellar ligament

Answer 13

From the apex of the patella to the tuberosity of the tibia; helps hold patella in place and serves as part of the “tendon” of the quadriceps Femoris muscle (patellar ligament is still distinct)

Question 14

Oblique popliteal ligament

Answer 14

From the lateral femur to the posterior tibia; reinforces posterior surface of the joint capsule

Continuation of the insertion of the semimembranosus muscle

Question 15

Arcuate popliteal ligament

Answer 15

From the lateral condyle of the femur to the head of the fibula; arches over the tendon of the popliteus muscle; stabilizes the posterior aspect of the knee joint

Question 16

Anterior Cruciate Ligament

Answer 16

From the front of the intercondylar eminence to the medial surface of the lateral femoral condyle posteriorly; Checks extension and anterior slipping of the tibia on the femur (or posterior displacement the femur on the tibia)

Question 17

Posterior Cruciate Ligament

Answer 17

From the posterior intercondylar fossa and to the lateral surface of the medial femoral condyle anteriorly; checks flexion and posterior slipping of tibia on the femur (or anterior displacement of the femur on the tibia)

Question 18

ACL tears

Answer 18

Occur when a severe force is directed anteriorly with the knee semiflexed. This is one of the most common knee injuries a resulting from skiing accidents. The ACL may tear way from the femur or tibia; tears more commonly occur in the mid portion of the ligament. The torn ACL will permit the tibia to slide anteriorly on the femur (anterior Drawer sign)

Question 19

PCL tears

Answer 19

PCL is strong, a rupture may occur when an individual lands on their tibial tuberosity with knee flexed (e.g. Knocked to the floor in basketball)
A tear frequently occurs in head-on collisions when seat belts aren’t worn and the proximal end of the tibia strikes the dashboard
Torn PCL will permit tibia to slide posteriorly on the femur-the posterior drawer sign

Question 20

Medial Meniscus

Answer 20

Crescent-shaped; attach to tibia anterior to the anterior cruciate ligament and to the posterior intercondylar area; deepens the medial tibial condyle; the medial (tibial) collateral ligament is firmly attached to the medial meniscus

Question 21

Lateral Meniscus

Answer 21

Nearly circular; attached to the tibia anterior to the ACL; posteriorly attached behind behind the intercondylar eminence anterior to the medial meniscus
(No lateral attachment to the LCL)

Question 22

Medial collateral ligament

Answer 22

A broad flat band located slightly posterior on the medial side of the knee joint. It’s attached proximal to the medial epicondyle of the femur right below the adductor tubercle. The distal attachment is to the medial condyle of the tibia. It resists forces that would push the knee joint medially. The MCL is fused to the medial meniscus

Question 23

Lateral Collateral Ligament

Answer 23

Rounded, more narrow and less broad than the MCL, the LCL stretches downward from the lateral epicondyle of the femur above, to the head of the fibula below. In contrast to the MCL, it isn’t fused with the lateral meniscus. Because of this, the LCL is less susceptible to injury

Question 24

Clinic: forces that damage the MCL

Answer 24

A force pushing on the knee joint from the lateral or outer surface causing stress on the medial side

Question 25

LCL tear

Answer 25

Can result from a force pushing the knee from the medial/inner side of the joint causing stress on the outside

Question 26

Clinic: Firm attachment of the MCL to the medial meniscus is of considerable clinical significance

Answer 26

Tearing of the MCL frequently results in concomitant tearing of the medial meniscus. This commonly occurs from a blow to the lateral side of the knee with twisting when the knee is flexed. The ACL may also tear resulting in an "UNHAPPY TRIAD"

Question 27

Bursae of the Knee Joint

Answer 27

Closed fibrous sac lined with synovial membrane producing synovial fluid; found in regions where musclesa and tendons rub against other muscles, tendons or bones; function by lubricating points of friction and dissipating force by distributing it thru a fluid medium

Question 28

Bursitis of the Knee

Answer 28

Constant irritation of a bursa may lead to over secretion and enlargement of the bursa, a condition known as bursitis `

Question 29

Knee Deformities | Genu Varum and Genu Valgrum

Answer 29

Varum: medial deviation of the tibia Valgrum: lateral deviation of the tibia These deformities cause unequal weight distribution (e.g. In the varum deformity, the medial side of the knee takes all the pressure, leading to wear and tear of medial meniscus)

Question 30

Genu Recurvatum

Answer 30

Knee is hyperextended such that the lower extremity curves. The convexity of the curve is Posterior and can be symmetrical or unilateral

Question 31

Popliteal Fossa

Answer 31

Diamond shaped depression posterior to the knee joint Bounded by: -Superolaterally: the biceps femoris muscle -superomedially: semimembranosus and semitendinosus muscles -inferolaterally and inferomedially: the lateral and medial heads of the gastrocnemius muscle -Posteriorly: skin and the popliteal fascia form the roof

Question 32

Femoral Artery and Vein (saphenous nerve) path thru adductor canal

Answer 32

They pass down in adductor canals (anterior thigh) and emerge from the adductor hiatus as the popliteal Artery and vein ` BUT the saphenous nerve passes under the septum (doesn't leave through adductor hiatus)

Question 33

Contents of the popliteal fossa

Answer 33

- termination of the small saphenous vein - popliteal artery and vein (continuation of the femoral vessels after they pass thru the adductor hiatus) - tibial (supplies posterior and anterior compartments) and common fibular nerves (moves down and wraps around head of fibula) - posterior cutaneous nerve of the thigh - popliteal lymph nodes and lymphatic vessels

Question 34

Popliteus

Answer 34

Prox: lateral epicondyle of femur Distal: posterior surface of proximal tibia innervation: tibial nerve Action: weakly flexes the knee; unlocks extended knww

Question 35

Plantaris

Answer 35

Prox: lateral side of distal femur Distal: calcaneous tendon Inner aviation: tibial nerve Action: Weak plantar flexion

Question 36

Interosseous Membrane | Osteology of tibia and fibula

Answer 36

a strong, fibrous sheet that connects the interosseous margin of the tibia and the interosseous margin of the fibula, filling the gap btwn the 2 bones except at the proximal and distal ends where there exist openings in the membrane that allow for passage of vessels Stabilizes the tibiofibular junction and provide attachment for many of the leg muscles

Question 37

Bones of foot

Answer 37

``` Calcaneus Talus Cuboid Navicular Cuneiform bones (lateral, intermediate, medial) ```

Question 38

Joints of the ankle

Answer 38

``` Ankle joint (talocrural) Subtalar joint ```

Question 39

Talocrural (ankle) Joint

Answer 39

Dorsiflexion and plantarflexion Hinge joint

Question 40

Subtalar joint (talocalcaneal joint)

Answer 40

Inversion and eversion of the foot

Question 41

Lateral Collateral ligament (complex) of the ankle

Answer 41

Set of 3 ligaments that resist inversion of the ankle joint More Commonly injured than the medial collateral ligament of the ankle Run from the lateral malleolus to the talus and calcaneus Posterior talofibular ligament Anterior talofibular ligament Calcaneofibular ligament

Question 42

Deltoid (Medial) Ligament

Answer 42

attach the medial malleolus to multiple tarsal bones Stabilizes the medial side of the ankle joint Prevents excessive eversion of the ankle joints Anterior parts of the ligament limit plantar flexion and posterior parts of the ligament limit dorsiflexion

Question 43

Ankle Sprain

Answer 43

Most common type: foot in plantar flexion, inverted and abducted Strain is focused on the calcaneofibular and anterior talofibular ligaments of the LATERAL LIGAMENT OF THE ANKLE JOINT

Question 44

Pott's Fracture-dislocation of the ankle

Answer 44

Occurs when the foot is forcibly exerted. This action pulls the extremely strong medial ligament Often the medial malleolus is pulled off the tibia-if this happens, the talus moves laterally, shearing off the lateral malleolus or breaking the fibula superior to the inferior tibiofibular joint