Flashcards in Lower Limb Deck (150):
Weight-bearing epiphyses are formed as a result of
weight bearing pressure
Traction epiphyses are formed as a result of
attachments of ligaments and muscles that exert force
The head of the femur is a ______ epiphysis
weight-bearing (fuses early 20s)
The greater trochanter is a ______ epiphysis
The head of the femur is oriented
upwards, medially, and slightly anteriorly (ante-verted)
T/F The anterior part of the head of the femur is within the socket
False, it lies anteriorly outside the socket, protected by the psoas bursa
T/F The psoas bursa communicates with the acetabular joint
False, but it may
The head of the femur articulates with
the roof of the acetabulum (thickest cartilage here)
What are the intra-articular structures of the hip joint?
fat pad, labrum, ligamentum teres
What is ligamentum teres?
Directs branch of obturator artery to femoral head in development until puberty
What is the role of the vertical bundle of trabeculae?
Weight-bearing in stance
What is the role of the arcuate bundle of trabeculae?
Resisting bending forces on the neck of the femur
What is the significance of the 2 trabeculae system in the neck of the femur?
At the inferior aspect of the arcuate bundle where the 2 intersect becomes a site of weakness in ageing and osteoporosis due to loss of trabeculae
At the hip joint, the line of gravity passes _________ the centre of the joint
At the knee joint, the line of gravity passes _________ the centre of the joint
in front of
At the ankle joint, the line of gravity passes _________ the centre of the joint
in front of
What is the 'close packed position'?
Position of greatest stability; articular surfaces meet as best they can with the capsules and ligaments taught - hip extension, abduction, and medial rotation (open packed is sitting cross-legged, least stability)
Which ligaments of the hip joint blend with the capsule?
Pubofemoral and ischiofemoral
Iliofemoral ligament attaches
ASIS to intertrochanteric line
What is the function of the iliofemoral ligament?
Tightens in extension to resist further extension; causes medial rotation in extension
extension of capsule around neck of femur; transmits retinacular blood vessels to epiphysis (growth) and head of femur (following closure)
Disruption of retinacular blood vessels in development causes
Perthe's disease - avascular necrosis of the femoral head
What is a screw-home mechanism?
The joint gets tighter as it goes into extension - eg in hip, medial rotation occurs with extension to lock the joint
_______ rotation occurs in stance, _______ rotation occurs in swing
Main movements of the hip are in the ________ plane
What is the function of gluteus maximus?
hip extension in extreme force/acceleration; stabilizes pelvis when rising from seated position
The principal role of the cuff muscles in the hip joint is to
pull the head of the femur into the socket; they can laterally rotate the hip as well
Range of flexion at the hip
Range of extension at the hip
Medial rotation of the hip is associated with
Lateral rotation of the hip is associated with
Gluteus medius and minimus _______ the thigh
Illiopsoas ________ the thigh
What is the critical role of gluteus medius and minimus?
Keeping the pelvis level in walking by pulling it down to prevent fall to the unsupported side
Injury to the gluteus medius and minimus results in
Trendellenberg gait where the pelvis is unstable and drops to the unsupported side
The hip joint is innervated by
articular branches of the femoral and obturator nerves
Referred pain from the hip via the obturator nerve presents
medial thigh above the knee
Referred pain from the lumbar spine and sacro-iliac joints presents
Hip flexion myotome
Hip extension myotome
Knee extension myotome
Knee flexion myotome
Plantar flexion myotome
Hallicus flexion myotome
Hallicus extension myotome
Blood supply to the hip joint comes from
retinacular fibres from the medial and lateral femoral circumflex arteries (profunda femoris; femoral a.)
Which vessels are susceptible in a #NOF?
retinacular and circumflex vessels
Posterior dislocation of the femur endangers
What is the normal neck-shaft angle of the femur?
135 deg (smaller in women)
neck-to-shaft angle less than 125
neck-to-shaft angle greater than 125
Why does a #NOF present with external rotation and shortening of the limb?
Spasm of gluteal muscles, especially external rotators
Pain of osteoarthritis in the hip joint commonly refers via
articular branches of the obturator nerve tf presenting on medial knee
How is congenital hip dislocation tested?
Abdudction of the flexed hip joint
How is congenital hip dislocation treated?
Hips braced in abducted position so that adductor magnus will pull along the line of the femur and the head of the femur back into the socket
What are the two types of hip dislocation?
Traumatic and congenital
Rotation of the knee only occurs during
The knee is in closed-pacjed position when in __________
Bursae in the knee joint sit
between the patella and the overlying ligament; between the femur and the quadriceps tendon; deep to popliteus and semimembranosus; between ligaments and bone
The knee gets its support primarily from
cruciates, collaterals, menisci, and muscles
The knee joint is most vulnerable in
flexion and rotation
Medial condyles of tibia and femur are
longer and thinner than the lateral
The femur rotates ______ on the tibia in moving from flexion to extension
What is the screw-home mechanism at the knee?
passive, occurs around the tightening ACL in the last 15-20deg of extension - the femur rotates medially on the tibia
________ is responsible for initiating flexion at the knee
Locking of the knee in extension is ________ whereas flexion of the knee is ________
Menisci are made of
T/F Menisci are covered in synovial membrane
False; this would wear out and cause swelling
Menisci are lubricated by
The synovial membrane covers
interior of the joint capsule and cruciates (anterior of PCL and ACL)
The cruciate ligaments are _____capsular but ______synovial
intracapsular but extra-synovial (outside the membrane)
Why is an ACL tear likely to be accompanied by bleeding?
because the cruciates are covered in synovial membrane which is very vascular
What is Osgood-Schlatter disease?
apophysitis of tibial tubercle - inflammation of the patellar ligament at the tibial tuberosity
The knee joint capsule is reinforced anteriorly by
patellar tendon and retinacular fibres (lateral and medial)
The knee joint capsule is reinforced laterally by
popliteus, biceps femoris, IT band
The knee joint capsule is reinforced medially by
pes anserinus tendons
The knee joint capsule is reinforced posteriorly by
oblique popliteal ligament from semimembranosus
What are the components of pes anserinus?
Say Grace Before Tea: Sartorius, Gracilis, Bursa, semiTendinosus
Which bursa communicate with the knee joint?
suprapatellar and those deep to popliteus and semimembranosus
What is a Baker's cyst?
Thickening of the lining of the bursa at the back of the knee, becomes irritated in flexion
The anterior cruciate ligament travels __________ from the ___________ to the __________
Posterolaterally, anterior tibia to lateral condyle
The posterior cruciate ligament travels __________ from the _________ to the __________
anteromedially, posterior tibia to medial condyle
What is the function of the ACL?
Stops anterior displacement of the tibia on the femur/posterior displacement of the femur on the tibia
What is the function of the PCL?
Stops anterior displacement of the femur on the tibia/posterior displacement of the tibia on the femur in flexion eg going down stairs
The ACL is ________ in flexion and ________ in extension
twisted; untwisted & tight (pulls femur medially to lock it)
ACL is commonly injured when
rotation occurs in the opposite direction (laterally) on the weight bearing leg - ie moving laterally in extension instead of medially
ACL repair grafts are commonly taken from
mid-portion of patellar tendon or a hamstring tendon from the pes anserinus (sartorius)
PCL is prone to injury in
falls on flexed knee; bumper bar impact on femur
The MCL attaches to
medial femoral epidondyle to medial tibia close to pes; deep part blends w/capsule and inserts into medial meniscus
What is the function of the MCL?
Resists valgus (abduction) forces and lateral rotation of the tibia; limit anterior displacement of tibia 2nd to ACL
The LCL attaches to
Lateral epidcondyle to head of fibula; separated from meniscus but popliteus tendon
What is the function of the LCL?
Resists varus (adduction) forces, medial movement of tibia
What is the 'unhappy triad'?
Tearing of the ACL, MCL, and medial meniscus usually due to lateral rotation of the femur on the planted tibia
What is the function of the menisci?
Absorb and distribute weight; increase area of contact by 1/3
Menisci move with the femur during ________ but the tibia during ________ and _______
rotation; flexion and extension
Menisci are endangered in
changing direction with the knee flexed
Locked knee occurs when
a flap of torn cartilage gets in the way of the articular surfaces and prevents unlocking
The meniscus receives blood supply to the
(because it is fibrocartilage it can have a blood supply) periphery but not the medial zone which is avascular (white)
What structures are responsible for stability at the patellofemoral joint?
raised lateral lip of femoral condyle (passive); medial patellar retinaculum/capsule (passive); strong vastus medialis (active)
What is the role of vastus medialis in stabilizing the patella?
Pulls patella in position during the last 15-20 degrees of extension
The Q angle is between
quadriceps tendon and patellar tendon
What is chondromalacia patellae?
inflammation of the underside of the patella and softening of the cartilage
Why is fibular fracture common with tibial fracture?
the 2 bones form a ring (ring hypothesis)
The tibial tuberosity is a _________ epiphysis
The ___________ eminence sits between the tibial plateaus and serves as attachment for
intercondylar eminence; cruciate and meniscal hook ligaments
Fractures in the distal 3rd of the tibia heal more slowly due to
less blood supply than proximal
The soleal line runs
obliquely along the posterior tibia (lateral to medial)
The superior tibiofibular joint is a ______________ joint and allows _________ movement
plane synovial; some gliding movement
The superior tibiofibular joint is supported by
LCL, ant and post tibiofibular ligaments, biceps femoris tendon
The inferior tibiofibular joint is a ___________ joint and
The inferior tibiofibular joint functions to
prevent separation of tib and fib in weight bearing
The inferior tibiofibular joint is reinforced by
ant and post tibiofibular ligaments, continuous fibres of IOM
What is the malleolar mortise?
formed by lateral malleolus, hinge of ankle joint that connects tib and fib to the talus
What is a March Fracture?
Stress fracture of the 2nd metatarsal due to it's wedged position between the 1st and 3rd metatarsal bones
What are accessory bones?
Secondary centres of ossification that don't fuse with the parent bone
Between talus and mortice between tib and fib malleoli
The taolcrural joint is reinforced by which ligament?
Inferior transverse ligament
The talocrural joint is a ____________ joint and permits ____________ and __________ only
synovial hinge; flexion and extension
What is the significance of the longer lateral malleolus?
Creates an oblique axis of rotation such that dorsiflexion is associated with eversion and plantar flexion is associated with some inversion - it's not a straight hinge
talocalcaneonavicular and calcaneocuboid
The ankle is more stable in ___________ due to
dorsiflexion; the talus is wider anteriorly and fits better into the mortice in dorsiflexion; hence the ankle is less stable in plantar flexion where the narrower posterior talus sits in the mortice
MCL of ankle joint
plantar calcaneonavicular ligament
Deltoid ligament/MCL has ___ parts
LCL at the ankle has ___ parts
_____% of ankle sprains are ________ injuries
The ankle is most vulnerable to injury in
inversion and plantarflexion
Inversion injuries to the ankle stress
LCLs and fibularis muscles
Pott's fractures are
associated with ankle inversion sprains - fracture of the medial malleolus and fibular shaft
Inversion injuries of the ankle commonly fracture
lateral malleolus of fibula
Inversion and eversion occur about the ________ joints
subtalar/talocalcaneal and taleocalcaneonavicular (TCN)
What is the function of the spring ligament?
Supports the head of the talus inferiorly into the TCN joint
What is the significance of the sinus tarsi?
carries the interosseus talocalcaneal ligament which binds the talus and calcaneus together, and the vascular sling which supplies the otherwise avascular talus
Where is the sinus tarsi?
between the talus and calcaneus, between the talocalcaneal articular surfaces
Fracture of the talus occurs at the _______ and endangers __________
neck; vascular sling - can get avascular necrosis of talus
Heel strike in running is in which plane?
Weight transfer to the forefoot in running puts the foot into
inversion (greater ROM)
The calcaneocuboid joint is a ___________ joint and allows ____________
plane synovial joint; rotary gliding movement for pronation and supination
What occurs in pronation of the foot?
eversion at subtalar and TCN, lateral rotation at calcaneocuboid
What occurs in supination of the foot?
inversion at subtalar and TCN, medial rotation at calcaneocuboid
What joints form the midtarsal joint?
TCN and calcaneocuboid
T/F The calcaneocuboid joint is involved in inversion and eversion with the TCN
False; it provides some rotation but is functionally independent of the TCN
Pronation and supination of the foot occur about the ___________ joint
calcaneocuboid (with subtalar and TCN involvement)
Pronation and supination of the foot refers to relative movement between
hindfoot (stable) and forefoot around it - up and down movement of the arch
What are the arches of the foot?
2 longitudinal: medial (higher) and lateral, 1 transverse hemi-arch