Lower Extremity Lecture Questions Flashcards
What are the lower limb borderlines?
-Iliac crest separates LL from posterior abdominal walls
-PSIS separates the LL from the muscles of the back
-Sacrotuberous ligament separates the LL from the perineum
-Inguinal ligament separates the LL from the anterior abdominal wall
What are the major areas of transition in the lower limb?
-Femoral triangle
-Popliteal fossa
-Tarsal tunnel
What are the 4 major entry and exit points between the lower limb, abdomen, pelvis, and perineum?
-The gap between the inguinal ligament and pelvic bone
-The greater sciatic foramen
-The obturator canal
-The lesser sciatic foramen
What is the communication between the LL and the pelvis?
-Obturator canal
-Greater sciatic foramen
-Lesser sciatic foramen
What is the communication between the LL and abdomen?
Gap between inguinal ligament and pelvis
False pelvis
-Superior region
-Technically part of the abdomen
True pelvis
-Lesser pelvis
-Inferior region
-Sacrum & coccyx
Pelvic wall
-Bones: pelvic bones
-Muscles: obturator internus and piriformis
-Ligaments: sacrospinous and sacrotuberous ligaments which connect each pelvic bone to the sacrum and coccyx and conver the two notches on the pelvic bones to the greater and lesser sciatic foramens
Female vs male pelvis
Females
-Pelvic inlet is more circular
-Ischial spine does not project as far medially in order for babies to come through
-Angle formed by the pubic arch is larger (80-85 degrees)
Males
-Pelvic inlet is heart shaped
-Ischial spine projects more into the pelvic cavity
-Angle formed by the pubic arch is smaller (50-60 degrees)
What are the 3 major apertures in the pelvic wall?
-Obturator canal
-Greater sciatic foramen
-Lesser sciatic foramen
What are the nerves in the gluteal region?
-Superior gluteal nerve
-Sciatic nerve
-Nerve to quadratus femoris
-Posterior femoral cutaneous
-Pudendal nerve
-Inferior gluteal nerve
What is a positive trendelenburg sign? What causes it?
-Hip drop on one side
-When the gluteus medius and minimus are inactive or weak due to an injury of the superior gluteal nerve
What is piriformis syndrome? What are the symptoms? What are the most common causes of it?
-When the piriformis muscle is tight and compresses the sciatic nerve
-Symptoms are pain, tingling, or numbness. Pain can extend all the way down the length of the sciatic
-Most commonly caused by prolonged sitting and running
What is the normal angle between the neck and shaft of the femur? What is it in kids?
-Normal is 125 degrees
-In kids it is normal to be 140 degrees (coxa valga)
What is coxa valga?
When the angle between the neck and shaft of the femur is greater than 140 degrees
What is coxa vara?
When the angle between the neck and shaft of the femur is less than 120 degrees
What is the ligamentum teres? What artery does it carry?
It is a flat band of connective tissue that attaches to the fovea of the femur and the acetabulum. It carries a branch of the obturator artery
What is the main blood supply of the hip?
Medial and lateral circumflex arteries of the femur
What is hemiarthroplasty?
When the head of the femur is replaced but the acetabular component is not
What is a total hip replacement?
When both the head of the femur and the acetabular component of the hip are replaced
What are the three capsular ligaments of the hip?
-Iliofemoral
-Ischiofemoral
-Pubofemoral
What is hip open-packed position?
-Flexion to 30 degrees
-Abduction to 30 degrees
-Slight external rotation
What movement does the iliofemoral ligament limit?
It limits hyperextension and external rotation
What movement does the pubofemoral ligament limit?
It limits hyperextension and abduction
What movement does the ischiofemoral ligament limit?
It limits hyperextension and internal rotation
What are the 3 compartments of the thigh?
-Anterior
-Medial
-Posterior
What do the anterior thigh compartment muscles do?
-Flex the thigh
-Extend the leg
What do the posterior thigh compartment muscles do?
-Extend the thigh
-Flex the leg
What do the medial thigh compartment muscles do?
-Adduct the thigh
What is the innervation to the anterior compartment of the thigh?
Femoral nerve (L2-L4)
What is the innervation to the medial compartment of the thigh?
Obturator nerve (L2-L4)
What is the innervation to the posterior compartment of the thigh?
Sciatic nerve (L4-S2)
What major structures go through the femoral triangle?
-Femoral nerve
-Femoral artery
-Femoral vein
-Lymphatic vessels
What are the boundaries of the femoral triangle?
-Base: inguinal ligament
-Medial: medial margin of the adductor longus
-Lateral: medial margin of the sartorius
-Floor: pectineus and adductor longus in the medial compartment & laterally by iliopsoas
-Apex: popliteal fossa
What muscles make up the anterior compartment of the thigh?
-Iliopsoas
-Rectus femoris
-Vastus lateralis
-Vastus medialis
-Vastus intermedius
What is a major role of the iliopsoas?
-Maintaining uprightposture
-Stronger contraction when walking or running up hill
What is the purpose of the patello-femoral joint?
It helps the quadriceps contract and helps them produce more force without placing wear and tear on the tendon
Which condyle of the femur extends more anteriorly? Which one posteriorly?
-The lateral femoral condyle extends more anteriorly
-The medial femoral condyle extends more posteriorly
What different types of intercondylar notches are there? Which one puts you at higher risk for ACL or PCL tear/injury?
-Type A
-Type U
-Type W
-Type A puts you at much higher risk for ACL or PCL injuries
Do the menisci get a lot of blood supply?
No, there is not much blood supply, so they don’t heal very well and typically need surgery
Which tibial plateau is larger than the other?
The medial tibial plateau is larger and more oval since the medial condyle of the femur is larger and more oval shaped than the lateral condyle
What is a major difference between the medial and lateral meniscus?
-The medial meniscus is attached to the MCL and the joint capsule
-The lateral meniscus is not attached to the LCL or the joint capsule so it is more mobile and less likely to be torn
What is the purpose of the menisci?
The menisci provide shock absorption and also help to spread synovial fluid
What happens to the pressure forces of the femur on the tibia when someone has a meniscectomy?
-When there is a meniscus, pressure forces are distributed across the whole tibia
-When someone has a meniscectomy, the area of pressure decreases, and more pressure is placed in the center of the tibia and not so much on the outsides
What is the purpose of the articularis genu?
The articularis genu pulls the joint capsule out of the way during knee extension
What is the purpose of the infrapatellar fat pad?
The infrapatellar fat pad helps to optimize the amount of synovial fluid needed in the joint capsule, which optimizes pressure
Why is the LCL not attached to the joint capsule?
Because the popliteal tendon causes a small gap in the fibrous membrane, so the LCL stays outside of the membrane
What are bursae? What is their function?
Bursae are sacs of synovial fluid that cushion tendons and allow them to move freely
What are the main ligaments of the knee?
-Coronary ligament
-Patellar ligament
-Anterior cruciate ligament (ACL)
-Posterior cruciate ligament (PCL)
-Tibial collateral ligament/medial collateral ligament (MCL)
-Lateral collateral ligament (LCL)
What is the purpose of the coronary ligament?
It is the ligament that attaches the menisci and the tibia in order to keep the menisci in place
What is the purpose of the patellar ligament?
It is a continuation of the quadriceps tendon and functions as a ligament
What are the functions of the ACL and PCL?
-The ACL prevents anterior displacement of the tibia
-The PCL prevents posterior displacement of the tibia
-There is always tension in both of these ligaments
What is unique about the PCL?
It is the strongest ligament in the knee and is typically only injured in car accidents
What are the functions of the MCL and LCL?
-MCL prevents valgus stress
-LCL prevents varus stress
What is the locking mechanism of the knee?
-Closed chain: Femur internally rotates on tibia
-Open chain: Tibia externally rotates on femur
What is the Q-angle? Is it different in males than females? If so, why?
-Quadriceps angle, it is formed by a line from the ASIS to the center of the patella and a line drawn straight upwards from the tibial tubercle
What is genu valgum? What stages of life is it normal?
-Knock knees
-It is normal from the ages of 3 to 12, then the children should outgrow it
What is genu varus? What stages of life is it normal?
-Bow legged
-It is normal in babies from 1 year to 3 years
What is the vascular supply to the knee?
-Descending genicular artery
-Popliteal & lateral circumflex femoral arteries
-Circumflex fibular artery
-Branches from anterior tibial artery
How many bones are there in the foot? How many joints?
There are 26 bones and 33 joints
What are the proximal tarsal bones?
Talus and calcaneus
What are the distal tarsal bones?
-Cuboid
-Medial, lateral, and intermediate cuneiforms
What is the intermediate tarsal bone that separates the distal and proximal tarsal bones?
The navicular bone
What forms the ankle joint?
The articulation between the talus and the tibia & fibula
What is the function of the sustentaculum tali?
-It supports the talus where the flexor hallucis longus attaches
-Forms groove
What is the function of the fibular trochlea?
It splits the tendons of 2 foot muscles
What is the purpose of the sesamoid bones on the plantar surface of the metatarsals?
They provide leverage for tendons so they stay in place and produce more force
What is different about the articulation between metatarsal I and II and the other metatarsal articulations?
-Metatarsal I and II do not articulate while the others do at the base of the metatarsals
What attaches at the tuberosity at the base of metatarsal V?
Fibularis brevis
What movement does the talocalcaneal (subtalar) joint allow?
Inversion and eversion
What movement does the talocrural (true ankle) joint allow?
Dorsiflexion and plantar flexion
What are the major ligaments at the ankle? What side are they on?
-Deltoid ligament : 4 main parts (medial side)
-Lateral ligaments (Anterior talofibular ligament, posterior talofibular ligament, calcaneofibular ligament)
-Anterior talofibular ligament accounts for 70% of ankle sprains
How common are ankle fractures?
They are the 2nd most common fractures in adults
What major structures come through the popliteal fossa?
-Popliteal artery and vein
-Tibial and common fibular nerves
What structures form the borders of the popliteal fossa?
-Semitendinosus
-Semimembranosus
-Biceps femoris long head
-Plantaris
-Lateral and medial heads of the gastrocnemius
What are the major veins in the lower limb? What do they form at the foot?
-Femoral vein
-Great saphenous
-Small saphenous
-The great and small saphenous veins form the dorsal venous arch at the foot
What is the purpose of the fibula?
Attachment of muscles and provides stability to the ankle
How are the tibia and fibula connected?
The interosseous membrane
What is the purpose of the interosseous membrane?
-It helps to distribute force
-Attachment site for muscles
What are the three compartments of the leg?
-Anterior
-Lateral
-Posterior
What divides the different compartments of the leg?
Intermuscular septa
What is compartment syndrome?
When the fascia is so thick that the muscles cannot expand
What is the deep fascia of the leg called?
Crural fascia
What nerve innervates the anterior compartment of the leg?
Deep fibular nerve
What nerve innervates the lateral compartment of the leg?
Superficial fibular nerve
What nerve innervates the posterior compartment of the leg?
Tibial nerve
What muscles are in the anterior compartment of the leg?
-Tibialis anterior
-Extensor hallucis longus
-Extensor digitorum longus
-Fibularis tertius
What muscles are in the lateral compartment of the leg?
-Fibularis longus
-Fibularis brevis
What muscles are in the posterior compartment of the leg?
-Gastrocnemius, soleus, plantaris (superficial)
-Popliteus, flexor digitorum longus, flexor hallucis longus, tibialis posterior (deep)
What nerve does the tibial nerve give rise to?
The sural nerve and medial calcaneal nerve
What does the popliteal artery split into?
The anterior and posterior tibial artery
What movements occur from the anterior compartment of the leg?
Dorsiflexion/inversion and eversion
What movements occur from the posterior compartment of the leg?
Plantar flexion
What movements occur from the lateral compartment of the leg?
Eversion & plantar flexion
What are retinaculums? What is their purpose?
-Strap like layer of connective tissue
-They help keep tendons in place
What structures go through the tarsal tunnel?
-Tibial nerve
-Posterior tibial artery
-Tendons of flexor hallucis longus, flexor digitorum longus, and tibialis posterior
What is tarsal tunnel syndrome? What is it caused by? What are the symptoms?
-It is when there is pressure on the tibial nerve
-The most common causes of tarsal tunnel syndrome are ankle sprains (swelling), inflammation, and flat feet
-Pain, numbness, tingling
What are the three arches of the foot?
-Medial longitudinal arch
-Lateral longitudinal arch
-Transverse arch
What ligaments and muscles support the arches of the foot?
-Short and long plantar ligaments
-Plantar aponeurosis
-Tibialis posterior tendond
-Tibialis anterior tendon
-Fibularis longus tendon
What is the plantar aponeurosis? What is its function?
-It is a thickening of deep fascia in the sole of the foot
-It helps the skin on the bottom of the foot stay taught during walking so it doesn’t slide
What is plantar fasciitis? What causes it? What are the symptoms? What happens if it is chronic?
-Plantar fasciitis is when the plantar aponeurosis is stretched during standing and walking
-It is caused by prolonged standing and walking
-Pain, tenderness in the sole of the foot
-Chronic plantar fasciitis can lead to calcaneal spurs
What muscles are in the dorsum of the foot?
-Extensor digitorum brevis
-Extensor hallucis brevis
What muscles are in the first layer in the sole of the foot?
-Abductor hallucis
-Flexor digitorum brevis
-Abductor digiti minimi
What muscles are in the second layer of the sole of the foot?
-Quadratus plantae
-Lumbricals
What muscles are in the third layer of the sole of the foot?
-Flexor hallucis brevis
-Adductor hallucis
-Flexor minimi brevis
What muscles are in the fourth layer of the sole of the foot?
-Dorsal interossei
-Plantar interossei
How many plantar interossei are there in the foot?
3
How many dorsal interossei are there in the foot?
4
What are the main arteries that supply the foot?
-Lateral plantar artery
-Medial plantar artery
-Posterior tibial artery
-Dorsal pedis artery
What nerves innervate the foot?
-Deep fibular nerve
-Medial plantar nerve
-Lateral plantar nerve
-Tibial nerve
