Wk13+14 Knee

Question 1

What are the extracapsular and intracapsular knee ligaments ?

Answer 1

extra: patellar, fibular collateral, tibial collateral, oblique popliteal, arcuate ligament

intra: cruciate ligaments, menisci

Question 2

How many structures connect to the medial and lateral meniscus ?

Answer 2

Medial: medial condyles of tibia and femur, medial collateral lig

Lateral: Lateral condyles of tibia and femur, popliteal tendon, posterior meniscofemoral lig

Question 3

What unique features can you name for the following ligaments: MCL, LCL, ACL, PCL

Answer 3

MCL: strong flat, within joint capsule; resists valgus force; weaker than LCL; attaches to medial meniscus
LCL: strong, cord-like, extracapsular; resists varus force; popliteus runs under it and seperates it from lateral meniscus; biceps femoris tendon split in 2 by it
ACL: prevents anterior dislocation of tibia; weaker than PCL
PCL: prevents posterior translation of tibia, stronger than ACL

Question 4

What do the oblique popliteal and arcuate ligaments do ?

Answer 4

stabilize the knee joint postero-laterally

Question 5

Compare and contrast the menisci.

Answer 5

• Outer 1/3 of menisci have vascular and nerve supply

Medial : less mobile than lateral one; attaches to ant. and post., intercondylar areas of MCL

Lateral: more mobile than medial meniscus; attaches to popliteus tendon and posterior meniscofemoral ligament.

Question 6

What are some notable bursae surround the knee ? Why are they notable ?

Answer 6

suprapatellar- attaches to articularis genu, can spread infection into knee capsule

anserine bursa- S.G.T pes muscles, tends to become inflammed.

Question 7

Explain the structure of the tibiofibular joints of the leg.

Answer 7

Fibular attachment has it’s own capsule which means it can be mobilized; interosseus membrane; inferiorly there is a tibiofibular syndesmosis made up of an ant. and post. lig, inferior transverse ligament, and tibiofemoral ligament.

Question 8

List the muscles that contribute to knee joint motions and the structures that limit the motion.

Answer 8

Ext: quadriceps; lateral meniscus in groove between patella and femoral condyle; ACL in groove in intercondylar fossa

Flex: Hamstrings; calf contacting thigh, hamstring length

IR:
flexed: semi-tendinosus and semimembranosus
extended: popliteus
collateral ligaments

ER: biceps femoris when knee is flexed; collateral ligaments and ACL wrapping around PCL

Question 9

Describe the boundaries and contents of the four compartments of the lower leg.

Answer 9

Ant: lateral surface of the tibial shaft and medial surface of fibula: tibialis anterior, EDL, EHL, Fibularis Tertius ( Propioceptive), Anterior Tibial Artery

Lateral: lateral surface of the fibula and posterior intermuscular septa and deep leg fascia: peroneal nerve, perforating branches of fibular artery, fibularis longus and brevis

Superficial Posterior: post. intermuscular septa, posterior fibula and tibia, dviided from deep by the transverse septa.; gastroc, soleus, plantaris ( propioceptive )

Deep Posterior: post. intermuscular septa, posterior fibula and tibia; nerves and vessels of the foot; popliteus, FHL, FDL, TP

Question 10

What muscles make up the triceps surae ?

Answer 10

Gastrocnemius heads and soleus
- contribute the most to plantar flexion

Question 11

What does the mnemonic Tom, Dick, and Harry correlate to ?

Answer 11

The muscles in the deep posterior compartment TP, FDL, FHL

Question 12

Which muscles contribute to maintaining the longitudinal arch of the foot ?

Answer 12

TA, Fibularis longus

Question 13

Describe landmarks that would test the following dermatomes and named nerves; L4, L5, S1, S2, Saphenous, Lateral Sural Cut., Sural

Answer 13

L4: medial half of big toe
L5: Dorsum of foot
S1: pinky toe
S2: medial heel
Saphenous: medial gastroc
Lateral Sural: lateral gastroc
Sural: lateral malleoulus

Question 14

What action would be tested for the following mytomes: L3-4, L4-5, L5-S1, S1-2

Answer 14

L3-4: knee extension
L4-5: hip ext, dorsiflexion, inversion
L5-S1: eversion, toe extension, knee flexion
S1-2: plantar flexion

Question 15

What deficits would be present if the following nerves are damaged: common fibular, superficial fibular, deep fibular, tibial

Answer 15

common: lack of SH of biceps femoris during knee flexion, foot drop

Superficial: weak eversion, and loss of sensation to lateral part of the leg and dorsal foot

Deep: weak dorsiflexion, dorsal foot muscles and web of skin between great and 2nd toes.

Tibial: loss of sensation to posterior leg and posterior heel and ankle; no knee flex, plantar flexion and toe flexion

Question 16

Describe the branching of nerves in the lower leg.

Answer 16

Tibial branch gives off common fibular nerves, fibular branch of sciatic gives off lateral sural nerve, the two meet up to make THE sural nerve.

Question 17

Describe the brancing of arteries and veins from the knee to the foot.

Answer 17

Arteries: the popliteal artery gives rise to the anterior and posterior tibial arteries as well as genicular arteries, the anterior tibial descends and becomes dorsalis pedis; the posterior becomes the fibular artery which gives rise to the medial and lateral plantar arteries

Veins: great saphenous veins drains into femoral vein
- small saphenous drains into popliteal first.

Question 18

Name the arteries that contribute to the genicular anastomosis.

Answer 18

superior and inferior lateral and middle genicular arteries

-descending genicular artery, descending branch of lateral circumflex artery, anterior tibial recurrent artery

See question 16 in study guide.

Question 19

What are the boundaries and contents of the popliteal fossa ?

Answer 19

boundaries: biceps femoris, semitendinosus, semimembranosus; heads of gastroc, roof formed by skin and fascia

contents: small saphenous, popliteal artery and vein, tibial and common fibular nerve, posterior femoral cut., lymph nodes and vessels

Question 20

What is chondromalacia patella and why does it occur ?

Answer 20

softening of articular cartilage on posterior surface of patella, “ runners knee”; caused by repetitive stress at end of flexion, direct blow to patella

Question 21

Explain the following concepts: Q-Angle, Genu Varus, Genu Valgus

Answer 21

Q-Angle: angle from ASIS to patella
Genu Varus: decreased Q-Angle, distal tibia oriented towards midline
Genu Valgus: increased Q-Angle, distal tibia oriented away from midline

Question 22

Why does patellofemoral syndrome happen ?

Answer 22

deterioration of articular cartilage due to increased Q-Angle, genu valgus.

Question 23

What is the unhappy triad of the knee and how does it occur ?

Answer 23

MCL tear, Medial Meniscus Tear, ACL tear, blow to lateral side

Question 24

What clinical presentation can we expect to see with a rupture of: ACL and PCL

Answer 24

ACL: anterior slippage of tibia
PCL: posterior slippage of tibia

Question 25

Why do meniscal tears have trouble healing ? Which meniscus is more often injured and why ?

Answer 25

poor blood supply to inner 2/3

medial meniscus, occurs with MCL, and ACL tears

Question 26

What is the difference between prepatellar bursitis and a bakers cyst ?

Answer 26

prepatellar bursitis: inflammation of the bursa due to friction and overuse of the knee

Baker Cyst: abnormal fluid collection

Question 27

Which bones are replaced during a total knee arthroplasty ?

Answer 27

distal femur, proximal tibia, and posterior patella; any point of articulation

Question 28

What is compartment syndrome and what could be some consequences of this condition ?

Answer 28

compression of vessels due to trauma, causes ischemia and tissue damage

fasciotomy may be a resolution

Question 29

Which nerve roots are tested by the following reflexes: patellar tendon, calcaneal tendon reflex

Answer 29

patellar: L2-4
calcaneal: tibial S1-2

Question 30

What are varicose veins ?

Answer 30

dilation of veins, incompetent valves; loose fascia, prolonged bed rest, muscular inactivity; can lead to DVT or thrombophlebitis