Wk13+14 Knee Flashcards
What are the extracapsular and intracapsular knee ligaments ?
extra: patellar, fibular collateral, tibial collateral, oblique popliteal, arcuate ligament
intra: cruciate ligaments, menisci
How many structures connect to the medial and lateral meniscus ?
Medial: medial condyles of tibia and femur, medial collateral lig
Lateral: Lateral condyles of tibia and femur, popliteal tendon, posterior meniscofemoral lig
What unique features can you name for the following ligaments: MCL, LCL, ACL, PCL
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
What do the oblique popliteal and arcuate ligaments do ?
stabilize the knee joint postero-laterally
Compare and contrast the menisci.
- 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.
What are some notable bursae surround the knee ? Why are they notable ?
suprapatellar- attaches to articularis genu, can spread infection into knee capsule
anserine bursa- S.G.T pes muscles, tends to become inflammed.
Explain the structure of the tibiofibular joints of the leg.
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.
List the muscles that contribute to knee joint motions and the structures that limit the motion.
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
Describe the boundaries and contents of the four compartments of the lower leg.
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
What muscles make up the triceps surae ?
Gastrocnemius heads and soleus
- contribute the most to plantar flexion
What does the mnemonic Tom, Dick, and Harry correlate to ?
The muscles in the deep posterior compartment TP, FDL, FHL
Which muscles contribute to maintaining the longitudinal arch of the foot ?
TA, Fibularis longus
Describe landmarks that would test the following dermatomes and named nerves; L4, L5, S1, S2, Saphenous, Lateral Sural Cut., Sural
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
What action would be tested for the following mytomes: L3-4, L4-5, L5-S1, S1-2
L3-4: knee extension
L4-5: hip ext, dorsiflexion, inversion
L5-S1: eversion, toe extension, knee flexion
S1-2: plantar flexion
What deficits would be present if the following nerves are damaged: common fibular, superficial fibular, deep fibular, tibial
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
Describe the branching of nerves in the lower leg.
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.
Describe the brancing of arteries and veins from the knee to the foot.
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.
Name the arteries that contribute to the genicular anastomosis.
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.
What are the boundaries and contents of the popliteal fossa ?
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
What is chondromalacia patella and why does it occur ?
softening of articular cartilage on posterior surface of patella, “ runners knee”; caused by repetitive stress at end of flexion, direct blow to patella
Explain the following concepts: Q-Angle, Genu Varus, Genu Valgus
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
Why does patellofemoral syndrome happen ?
deterioration of articular cartilage due to increased Q-Angle, genu valgus.
What is the unhappy triad of the knee and how does it occur ?
MCL tear, Medial Meniscus Tear, ACL tear, blow to lateral side
What clinical presentation can we expect to see with a rupture of: ACL and PCL
ACL: anterior slippage of tibia
PCL: posterior slippage of tibia
Why do meniscal tears have trouble healing ? Which meniscus is more often injured and why ?
poor blood supply to inner 2/3
medial meniscus, occurs with MCL, and ACL tears
What is the difference between prepatellar bursitis and a bakers cyst ?
prepatellar bursitis: inflammation of the bursa due to friction and overuse of the knee
Baker Cyst: abnormal fluid collection
Which bones are replaced during a total knee arthroplasty ?
distal femur, proximal tibia, and posterior patella; any point of articulation
What is compartment syndrome and what could be some consequences of this condition ?
compression of vessels due to trauma, causes ischemia and tissue damage
fasciotomy may be a resolution
Which nerve roots are tested by the following reflexes: patellar tendon, calcaneal tendon reflex
patellar: L2-4
calcaneal: tibial S1-2
What are varicose veins ?
dilation of veins, incompetent valves; loose fascia, prolonged bed rest, muscular inactivity; can lead to DVT or thrombophlebitis
