Posterior Thigh and Popliteal Fossa

Question 1

Common proximal attachment of posterior thigh muscles

Answer 1

Ischial tuberosity- except short head of biceps femoris

Question 2

Common innervation of posterior thigh muscles

Answer 2

Tibial division of sciatic nerve- except short head of biceps femoris

Question 3

Common functions of posterior thigh muscles

Answer 3

Leg flexion at knee

Thigh extension at hip- except short head of biceps femoris

Question 4

Semitendonosus OINA

Answer 4

O: ischial tuberosity
I: pes anserinus - anteromedial superior tibia
N: Tibial division of sciatic nerve
A: extend thigh, flex leg, medially rotate flexed leg

Question 5

Attachments to pes anserinus listed superficial to deep

Answer 5

Sartorius
Gracilis
Semitendonosus

Question 6

Pes anserine bursitis

Answer 6

Inflammation of anserine bursa located between pes anserinus and the MCL
Results in constant, aching pain aggravated by activity such as climbing stairs, specifically flexion and internal/medial rotation of knee

Question 7

Semimembranosus OINA

Answer 7

O: ischial tuberosity
I: posterior part of medial tibial condyle
N: tibial division of sciatic nerve
A: extend thigh, flex leg, medially rotate flexed leg

Question 8

Semimembranosus distal tendon- explain

Answer 8

Divides into 2 main parts, one goes to medial tibial condyle, the other becomes oblique popliteal ligament
This ligament reinforces intercondylar portion of knee joint capsule and forms part of popliteal fossa floor

Question 9

Biceps femoris long head OINA

Answer 9

O: ischial tuberosity
I: lateral aspect of fibular head
N: tibial division of sciatic nerve
A: extend thigh, flex leg, laterally rotate flexed leg

Question 10

Biceps femoris short head OINA

Answer 10

O: lateral lip of linea aspera and lateral supracondylar line
I: lateral aspect of fibular head
N: common fibular division of sciatic nerve
A: flex leg, laterally rotate flexed leg

Question 11

Grade I hamstring injury

Answer 11

Mild
Small disruption in structural integrity
Minor swelling and pain
No or minimal loss of strength

Question 12

Grade II hamstring injury

Answer 12

Moderate
Partial tears with some intact muscle fibers
Pain present
Definite loss of strength

Question 13

Grade III hamstring injury

Answer 13

Severe
Complete tear
Swelling, severe pain and typically with accompanied hematoma
Complete loss of motor function

Question 14

Perforating arteries of deep femoral/profundal femoral artery

Answer 14

There are three perforating branches, and the termination of the deep femoral artery becomes the 4th branch
Supplies posterior thigh muscles and adductor magnus
Courses from anterior from posterior by piercing adductor magnus

Question 15

Descending branch of lateral femoral circumflex artery

Answer 15

Descends anterior thigh

Supplies genicular anastomosis

Question 16

Descending genicular artery

Answer 16

Arises from femoral artery in adductor canal

Supplies genicular anastomosis

Question 17

Sciatic nerve tibial division innervates

Answer 17

L4-S3
Long head of biceps femoris L5-S2
Semitendinosus L5-S2
Semimembranosus L5-S2
Hamstring portion of adductor magnus (L4)

Question 18

Common fibular division of sciatic nerve innervates

Answer 18

L4-S2

Short head of biceps femoris L5-S2

Question 19

Semitendinosus OINA

Answer 19

O: ischial tuberosity
I: pes anserinus
N: tibial division of sciatic nerve
A: extend thigh, flex leg and rotate it medially

Question 20

Boundaries of the popliteal fossa

Answer 20

Superomedially: semimembranosus, semitendinosus
Superolaterally: Biceps femoris
Inferolaterally: lateral head of gastrocnemius
Inferomedially: medial head of gastrocnemius

Question 21

Contents of popliteal fossa listed superficial to deep

Answer 21

Tibial nerve, common fibular nerve, sural nerve
Popliteal vein, branches and lymph nodes
Popliteal artery and branches

Question 22

Popliteal artery

Answer 22

Continuation of femoral artery after passing through adductor hiatus
Terminates by dividing into anterior/posterior tibial arteries
Deepest structure in popliteal fossa
Gives rise to genicular branches

Question 23

Genicular anastomosis

Answer 23

Important collateral circulating bypassing popliteal artery if knee is fully flexed for long periods of time or if there are narrowed/occluded popliteal vessels
Supplies articular capsule and ligaments of knee joint
Includes: Popliteal artery, descending branch of lateral femoral circumflex artery, descending genicular artery saphenous and articular branches.

Question 24

Popliteal vein

Answer 24

Lies superficial to and in same fibrous sheath as popliteal artery
Termination point of small saphenous vein
Formed by union of anterior/posterior tibial veins, usually near inferior border of popliteus muscle
Becomes femoral vein after traversing adductor hiatus

Question 25

Popliteal fossa lymphatics

Answer 25

Cutaneous fluid drains to superficial popliteal nodes along small saphenous vein Deep leg and foot drains to deep popliteal nodes along popliteal vein Proximal drainage accompanies femoral vein to deep inguinal nodes Continued drainage follows venous return

Question 26

Tibial nerve

Answer 26

Larger of sciatic nerve (which divides into tibial/fibular nerves near superior angle of popliteal fossa) Descends centrally through popliteal fossa Most superficial relative to popliteal vein/artery Runs distally with posterior tibial artery/vein

Question 27

Tibial nerve innervates

Answer 27

Posterior leg muscles Knee joint Skin on posterior leg via medial sural cutaneous nerve

Question 28

Common fibular nerve

Answer 28

Descends obliquely on lateral side of popliteal fossa, medial to biceps femoris Leaves popliteal fossa by passing superficially to lateral head of gastrocnemius Winds around head and neck of fibula (susceptible to injury)

Question 29

Common fibular nerve innervates

Answer 29

Anterior leg muscles via deep fibular nerve Lateral leg muscles via superficial fibular nerve Skin on posterolateral leg via lateral sural cutaneous nerve

Question 30

Sural nerve

Answer 30

Cutaneous nerve of posterior leg and lateral aspect of ankle and foot Runs inferiorly with small saphenous vein, passes inferior to lateral malleolus to lateral side of foot Composed of medial sural cutaneous nerve from tibial, and sural communicating branch from common fibular or lateral sural cutaneous nerve

Question 31

Superficial fibular nerve innervates

Answer 31

Fibularis longus/brevis and skin on distal third of anterior surface of leg and dorsum of foot

Question 32

Deep fibular nerve innervates

Answer 32

Anterior muscles of leg, dorsum of foot, skin of first interdigital cleft, sends articular branches to joints it crosses

Question 33

Metaphyseal distal femoral fracture

Answer 33

Traverse fracture across the shaft | Most common distal femoral fracture

Question 34

Physeal distal femoral fracture

Answer 34

Transverse fracture involving epiphyseal plate Commonly described by Salter-Harris classification: I- through growth plate II- through growth plate and metaphysis III- through growth plate and epiphysis IV- through all three elements V- crush injury of growth plate

Question 35

Distal femoral fracture may disrupt what and how

Answer 35

Posterior displacement can disrupt neurovasculature due to close proximity to femur in popliteal fossa

Question 36

Distal femoral fracture nerve injury

Answer 36

Motor injury with foot drop | Sensory deficits to dorsal or plantar foot

Question 37

Acute compartment syndrome

Answer 37

Increased pressure in a closed fascial compartment Most commonly due to hemorrhage and/or edema Symptoms- persistent deep ache/burning pain Paresthesia Pain with passive stretch Muscle weakness

Question 38

Popliteal (bakers) cysts

Answer 38

Swelling in the popliteal fossa due to enlargement of the gastrocnemius-semimembranosus bursa Often communicates with knee joint space, and contain synovial fluid Associated with degenerative inflammatory joint disease or joint injury Very asymptomatic and typically detected by imaging studies performed for other reasons

Question 39

Complications of popliteal cysts- enlargement

Answer 39

``` Presents similar to DVT Erythema and edema due to vein compression Ischemia due to arterial compression Nerve entrapment Positive Homans sign ```

Question 40

Complications of popliteal cysts- rupture

Answer 40

``` Simulates thrombosis or muscle rupture Warmth, tenderness and erythema Ecchymoses Compartment syndromes My be indolent with only edema ```

Question 41

Peripheral aneurysm

Answer 41

Localized enlargement of an artery due to weakening of arterial wall Popliteal artery aneurysms are most common true peripheral aneurysm Symptoms: claudication or ischemic pain at rest, sensory/motor nerve deficit, severe pain behind knee

Question 42

Peripheral artery disease

Answer 42

Atherosclerosis leading to peripheral artery occlusion Lack of blood flow leads to pain in affected muscle groups Symptoms: ischemic pain at rest, non-healing ulcer, gangrene