lower limb bones and joints Flashcards
parts of the femur
head (neck, greater and lesser trochanters), shaft (linea aspera, lateral and medial supracondylar ridges), end (medial and lateral condyles, patellar groove, intercondylar fossa, popliteal surface)
femoral injuries and common age group
- transcervical (common in elderly after falling): avascular necrosis of the head, leg shortening, lateral rotation of toes
- intertrochanteric (common in young after direct trauma): extracapsular fracture line, shortening and rotation of leg
- shaft: upper 1/3 has proximal fragment flexed, middle 1/3 and distal 1/3 has distal fragment rotated
parts of patella
posterior surface (covered with cartilage, lateral and medial facet articulate with femur condyles), anterior surface
cause of patellar dislocation
natural tendency of patella to dislocate laterally due to upward and lateral pull by quadriceps
parts of tibia
lateral and medial condyles, intercondylar eminence, fibula notch, triangular shaft, tibial tuberosity, soleal line, medial malleolus
parts of fibula
head w styloid process, shaft, lateral malleolus (extends further than medial malleolus of tibia)
types of tibia/fibula fractures
- tibial shaft fractures: most common
- transverse stress fractures of the inferior 1/3 of the tibia
- fibular fractures proximal to the lateral malleolus: assoc with dislocations of the ankle
- head and neck fibula fractures (subcutaneous bone) upon heavy lateral impact
name ALL the tarsals (tiger cubs need MILC)
talus, calcaneum, navicular, medical cuneiform, intermediate cuneiform, lateral cuneiform, cuboid
parts of the talus
head (articulates with navicular), neck (attachment for tendons), trochlea (two articular facets for tibial malleolus and fibular malleolus)
parts of the calcaneum
largest foot bone, forms the heel
anterior (articulates with cuboid), posterior (forms heel, attaches to Achilles tendon), superior (articulates with talus), inferior, medial (attachment for ankle ligaments), lateral
types of tarsal fractures
- talus fracture (swollen foot): neck due to violent dorsiflexion of ankle against anterior edge of tibia, body due to jumping from height
- calcaneum / don juan fracture: compression due to falls from height
- metatarsal fracture: stress fractures due to forced inversion of foot
toe bones
1-5th metatarsals, 1-5th proximal phalanges, 1-5th medial phalanges, 2-5th distal phalanges (big toe doesn’t have a distal phalange)
bones in the medial longitudinal foot arch
calcaneum, talus, navicular, 3 cuneiform bones, 1-3rd metatarsals
bones in the lateral longitudinal foot arch
calcaneum, cuboid, 4-5th metatarsal
bones in the transverse foot arch
metatarsal bones, cuboid, 3 cuneiform bones
function of foot arches
distribute weight over the foot, shock absorbing, propulsion of foot, concavity protects the nerves and vessels of the sole
principles supporting the foot arches
- key stone (keystone centre bone in the arch)
- staples (intersegmental ties w ligaments and muscles)
- tie beam (ends of the arch are tied together w muscles and aponeuroses)
- suspensory (arch is suspended from above by ligaments and muscles)
pes planus pathology
• medial longitudinal arch is collapsed or depressed
• forefoot is displaced laterally and everted due to excessive fatigue of muscles
• plantar, medial and lateral ligaments become permanently stretched in the long run causing bones to change shape
therefore flat foot
pes cavus pathology
• medial longitudinal arch is very high
• due to muscle imbalance
• nerves on the sole of the foot may be compressed, leading to pain
hence high arch
hip joint type of joint
ball and socket synovial joint (ball is femoral head, socket is acetabulum)
ligaments supporting the hip joint (PIITH)
pubofemoral ligament (prevents excessive lateral rotation), iliofemoral ligament (prevents hyperextension), ischiofemoral ligament (prevents hyperextension and medial rotation), transverse acetabular, head of femur ligament
joint capsule over hip joint anatomy
fibrous capsule from the acetabular labrum, through the intertrochanteric line, to the margin of articular hyaline cartilage
thickened by iliofemoral, pubofemoral, ischiofemoral ligaments forming a psoas bursa with outer longitudinal and inner circular fibres
movements and nerve supply of hip joint
flexion (L2, L3), extension (L4, L5), adduction (L2, L3), abduction (L4, L5), medial rotation (L2, L3), lateral rotation (L4, L5)
blood supply to femoral head
trochanteric anastomosis of lateral and medial circumflex femoral arteries (mostly medial) + cruciate anastomosis
blood supply to femoral head in children
obturator artery runs through epiphyseal growth plate + lateral and medial circumflex femoral arteries (hence no avascular necrosis after fracture)
hip joint injuries
- traumatic dislocation of head of femur: displaced posteriorly out of acetabulum, injuring sciatic nerve (paralysis of hamstrings and muscles distal to the knee)
- avascular necrosis: dislocation or fracture of femoral neck disrupting the anastomosis of the obturator artery and medial circumflex femoral artery
- joint pain: due to referred pain from femoral, obturator, sciatic nerves crossing the hip joint
knee joint type of joint
modified synovial hinge joint (femoropatellar articulation in a synovial gliding joint + lateral and medial femorotibial condyles)
knee joint innervation
femoral, tibial, common peroneal, obturator nerves
extracapsular ligaments of the knee
ligamentum patellae, lateral fibular collateral ligament, medial tubular collateral ligament, oblique popliteal ligament
intracapsular ligaments of the knee
anterior cruciate ligament (anterior intercondylar area of tibia to lateral condyle of the femur): prevents hyperextension
posterior cruciate ligament (posterior intercondylar area of tibia to medial condyle of femur): prevents hyperflexion
anterior bursae of the knee
suprapatellar, prepatellar, superficial infrapatellar, deep infrapatellar
posterior bursae of the knee
popliteal and semimembranosus
attachment of the menisci of the knee joint
medial and lateral menisci are attached anteriorly by the transverse ligament of the knee, and also attached to the intercondylar area of the tibia and fibrous layer of the knee joint capsule
medial vs lateral meniscus
c shaped vs circular
broader posteriorly vs smaller
attached to ACL and PCL vs more freely movable
more prone to injuries vs less prone to injuries
locking and unlocking mechanism of the knee
locking = medial rotation of the femur on the tibia
unlocking = contraction of popliteus to laterally rotate the femur 5° on the tibial plateau
movements of the knee
flexion (hamstrings), extension (quadriceps femoris), external rotation (biceps femoris), internal rotation (semimembranosus, semitendinosus, popliteus)
blood supply to the knee
anastomosis of femoral, popliteal, anterior and posterior tibial arteries
ligamentous injuries of the knee
- medial collateral ligament tear: during excessive abduction
- lateral collateral ligament tear: during excessive adduction
- anterior cruciate ligament tear (COMMON): leads to anterior drawer sign, femur slides forward
- posterior cruciate ligament tear (rare): leads to posterior drawer sign, femur slides backwards
cruciate ligament tears cause haemathrosis and swollen joint
what is O’Donoghue’s triad?
ruptured MCL, ruptured ACL, and torn medial meniscus (due to force applied on a flexed and rotated knee)
menisci injury of the knee
medial menisci more prone to damage due to connection to MCL (restricts its movement): leads to positive McMurray test (clunk and pain when knee is rotated externally and extended)
proximal tibiofibular joint type of joint
synovial plane joint between lateral condyles of tibia and head of fibula
distal tibiofibular joint type of joint
syndesmosis type of fibrous joint between lower end of tibia and lower end of fibula, strengthen by interosseous membrane
ankle joint type of joint
synovial hinge joint between medial and lateral malleoli, lower end of tibia, talus body
innervation of ankle joint
deep peroneal, tibial nerves
ligaments in ankle joint
medial (deltoid) ligament, lateral ligaments, anterior talofibular ligament, posterior talofibular ligament, calcaneofibular ligament
factors stabilizing the ankle joint
- close interlocking of articular surfaces
- strong medial and lateral collateral ligaments
- inferior transverse tibiofibular ligament
- tendons crossing in front and behind of ankle joint
movements of ankle joint
dorsiflexion (tibialis anterior), plantar flexion (gastrocnemius, soleus)
ankle injuries
- sprains of lateral ankle: caused by excessive inversion of the foot, usually anterior talofibular ligament
- sprains of medial ankle: caused by excessive eversion of the foot, less common due to strength of medial ligament
- fracture dislocations of ankle joint: caused by forced external rotation and overeversion of the foot
talocalcaneal (subtalar) joint type of joint
plane synovial joint between talus and calcaneum, surrounded by medial, lateral, posterior and interosseous talocalcaneal ligaments
talocalcaneonavicular joint
synovial joint between talus, calcaneum and navicular, forms part of the transverse tarsal joint
calcaneocuboidal joint type of joint
synovial plane joint between calcaneus and cuboid, forms part of transverse tarsal joint
significance of transverse tarsal joint
compound joint consisting of the talocalcaneonavicular joint and the calcaneocuboidal joint, transection across this joint is performed during surgical amputation of the foot
movements of the subtalar joint
inversion (tibialis anterior, tibialis posterior), eversion (fibularis longus, fibularis brevis)
gaits and their significance
• antalgic gait: limping gait
• Trendelenburg sign: waddling gait with hip elevated at the pathological side
• parkinsonian gait: shuffling, sometimes festinant gait
• ataxic gait: wide-based, unbalanced gait
• dorsal column injury: high-stepping gait due to foot drop
