lower extremity Gao notes - Quiz 1

most frequent site of tibia fx

* narrowest at jx of middle and inferior thirds (like clavicle; away from center) * most common site for a compound fx * fx through nutrient canal --> damage to nutrient artery, predisposes nonunion of bone fragments/extra healing time

most common femoral fx

* neck fx most problemmatic: instability of fx site, thin periosteum covering area = extremely limited powers of osteogenesis * retinacular arteries (arising from medial circumflex femoral arteries) run parallel to neck on way to supply femoral head; vulnerable to injury in this fx, leading to head necrosis and bleeding into hip jt * often results from indirect violence, slipping on icy surgace/tripping over rug

fibula fx

* often 2-6 cm proximal to distal end of lateral malleolus * often associated with ankle jt fx/dislocation * many combined with tibial fx

most common long bone to fx

* tibia (body is unprotected anteromedially) * poor blood supply, even simple fx may take up to SIX MONTHS to heal!

# phalanges

14

primary hip bones begin to fuse when?

15-17 y/o

hip bone fusion complete when?

20-25 y/o

thigh's fascial intermuscular septa

3 septa; lateral is strong (extending from ITB to lateral lip of linea aspera and lateral supracondylar line of femur), other two are weak

# metatarsal bones

5

surface anatomy landmarks: iliac tubercle

5 to 6 cm posterior to ASIS, widest pt of iliac crest

intertrochanteric line

anterior

femur length

approx 1/4 a person's height, associated with a striding gait

hip fx for adolescents/young adults, in sports requiring jerk motion?

avulsion fx where muscles attach (ischial tuberosity, ASIS and AIIS, ischiopubic rami); occur at apophyses (bony projections that lack secondary ossification centers)

fx sesamoid bones of great toe

crushing injury (eg. Heavy object falling on toe)

diagonal tibial fx

eg. when tackled in football game, torsion in skiing accident

lateral malleolus of fibula

extends approx 1 cm more distally; more prominent and post. than medial malleolus; articulates with lateral surface of talus

anatomical position: internal aspect of body of pubis

faces almost directly superiorly (forms floor on which urinary bladder rests)

anatomical position: acetabulum

faces inferolaterally, with inferior acetabular notch

heaviest bone in body

femur

longest bone in body

femur

common source of bone for grafting

fibula (middle third is best, b/c w/blood supply); if long piece is removed --> walking, running, jumping all can be normal!

calcaneus lateral tubercle

first to strike floor (where shoe wears down!)

sciatic nerve

from sacral plexus, thru greater sciatic foramen (inf. glute region) into post. thigh; at apex of popliteal fossa, divides into: 1) common fibular (peroneal) and 2) tibial nerves

two major superficial veins in lower limb

great and small saphenous

vein graft candidate?

great saphenous v. often used for coronary arterial bypass; readily accessible, long, rich in elastic and muscular fibers; good coverage by other leg veins

saphenous opening of fascia lata

great saphenous vein

metatarsal fx

heavy object falling on foot/run over by wheel; common in dancers; fatigue fx from prolonged walking

avulsion fx 5th MT tuberosity

if foot's suddently inverted, may be avulsed by fibularis brevis tendon; common in bball and tennis players

chief flexor of thigh

ilipsoas; also a postural muscle --> active during standing by preventing hip hyperextension

tibia's vascular groove

immediately distal to soleal line; obliquely directed groove, leads to large nutrient foramen

what margin of acetabulum is deficient?

inferior: acetabulum notch (looks like cup with bottom piece of its lip missing), room for vessels

anatomical position: obturator foramen

inferomedial to acetabulum

other femoral fx common to older women who fall down

intertrochanteric (btn trochanters) and pertrochanteric (through the trochanters)

thinnest part of tibia

jx of middle and distal thirds

genu valgum

knock-knee, more knee jt issues than varum --> articular cartilage wear and tear

base of 5th MT

large tuberosity, projects over lateral margin of cuboid

angle of inclination

largest at birth (almost straight) and gradually diminishes (becomes more acute) until adult angle is reached (115-140 degrees, ave. 126 degrees); angle is less in females (breadth of pelvis, and greater obliquity of body of femur)

plantar surface of head of 1st MT

medial and lateral sesamoid bones (w/o, too much pressure on flexor tendon)

body of talus

narrow posteriorly, with groove for a tendon

what part of the femur has the most strain?

neck, due to head and neck being at an angle (which allows for hip joint mobility); fx here in elderly due to slight stumble even! THIS is what's injured in elderly person's "broken hip"

fibula articulates w/femur?

no

TFL

no direct action on leg; a thigh flexor, but doesn't act independently (is in concert with iliopsoas)

hip fx common?

no, even in contact sports (except high-energy severe trama, eg car accident; also skiing and ice dancing)

SI joint smooth?

no, really ugly! Has to match perfectly

fibula weight bearing?

no; mainly serves for muscle attachment, and lateral malleolus helps hold talus in socket

talar neck fx

ocurs during severe dorsiflexion of ankle (eg, slamming on break while driving); body of talus sometimes dislocates posteriorly

transverse stress (march) fx of tibia

of inferior third; common in people who take long walks when they're not conditioned

middle and distal phalanges of 5th digit

often fused due to disuse (esp. in elderly); NO jt mobilization!

tibial tuberosity

on ant. border/crest; DA for patellar ligament

pectineal line

on femur, prominent ridge from central part of linea aspera to base of lesser trochanter

anatomical position: tip of coccyx

on level with the superior half of body of pubis

intertrochanteric crest

posterior

head of tibia

proximal end

AP compression of hip bone, fx?

pubic rami fx

VMO

realigns patella medially; the ONLY dynamic medial stabilizer (active through whole ROM), arises from adductor magnus tendon; can be activated as a single motor unit

boot-top tibial fx

results from high-speed fwd fall in ski boots; usually comminuted fx

longest muscle in body

sartorius (but none of its actions are strong, other thigh muscles produce same mvmts)

foot pain areas

sustentaculum tali (superior border of medial calcaneus), navicular tuberosity (medial surface projects inferiorly), base of 5th MT

only tarsal bone with no muscular or tendinous attachments?

talus

which tarsus bone articulates with leg?

talus (the only one that does!)

surface anatomy landmarks: pubic tubercle

thumb's width from pubic symphysis; guide to superficial inguinal ring; important landmark in diagnosis/repair of inguinal femoral hernias

most common site for a compound fx (skin broken, BVs torn)

tibia's narrowest at jx of middle and inferior thirds

body of tibia

triangular: medial, lateral (interosseous), and posterior surfaces

anatomical position: symphyseal surface of pubis

vertical

thigh contusions

"charley horse," cramping of an individual muscle, due to ischemia, or contusion/tearing of muscle fibers --> hematoma (quads is most common site of thigh hematoma, from direct trauma)

hip contusions

"hip pointers," contusion of ASIS usually; bleeding from ruptured capillaries infiltrates muscles, tendons, other soft tissues

adductor longus injuries

"rider's strain," muscle strain of adductor longus; "rider's bones," ossification of tendons of these muscles

chondromalacia patellae

"runner's knee," common issue; due to quad imbalance, stemming from overstressing knee, a blow to patella, or extreme flexion

slipped epiphysis of femoral head

* 10-17 y/o, due to acute trauma or repetitive microtraumas (esp. abduction/lat. rotation of thigh), --> progressive coxavara * initial symptoms: hip discomfort, may refer to knee

cuneiform bones

* 1st (medial) is largest * 2nd (middle) is smallest * 3rd (lateral) * each articulates with 1) navicular, 2) base of its metatarsal (1st 3 MTs), and lateral 3rd cuneiform articulates with cuboid

coxa vara

* angle of inclination is decreased --> mild shortening of lower limb, limits hip abduction * leads to genu valgum (knock-knees)

coxa valga

* angle of inclination is increased --> mild lengthening of lower limb, limits hip adduction * caused by a slipped epiphysis of the femoral head * often combined with genu varum (bow-leggedness)

deep fascia of thigh

* fascia lata (L. lata = broad) * superior attachment: inguinal ligament, pubic arch, body of pubis, pubic tubercle, SC tissue (Scarpa's fascia) of lower abdominal wall * lateral attachment: iliac crest * post: iliac crest, sacrum, coccyx, sacrotuberous ligament, ischial tuberosity * dist: exposed parts of bones around knee, continuous with crural fascia

gluteal fold vs. sulcus/line

* fold = containing fat, coincides with inf. border of glute max * line = skin crease inf. to gluteal fold, indicates separation of butt from thigh

calcaneal fx

* hard fall from ladder on heal --> comminuted * usually disabling b/c disrupts subtalar (talocalcaneal) jt

femoral body fx

* may break or spiral due to violent injury * in cases of comminuted spiral fx, may take up to 20 weeks to firm union of fragments

cuboid

* most lateral bone in distal row of tarsus * groove for fibularis (peroneus ) longus muscle is anterior to cuboid tuberosity on lateral and inferior surfaces

# tarsal bones

7

adductor canal boundaries

AKA subsartorial or hunter's canal; 15cm-long fascial tunnel in middle third of thigh. Vastus medialis (lateral and anterior), sartorius (medial), adductors longus and magnus (post). Runs from apex femoral triangle to adductor hiatus; overlying sartorius muscle turns it into a canal.

BV injury in femoral neck fx/hip jt dislocation?

Medial circumflex femoral art.

Iliopsoas paralyzed?

TFL hypertrophies to try and compensate

lateral compression pelvis/falls on feet (eg, from roof), fx?

acetabula fx

ITB

additional longitudinal fibers within fascia lata

muscles of medial thigh: adductors

adductor longus, brevis, magnus, gracilis, obturator externus, pectineus --> all supplied by obturator n. (L2-L4) except pectineus (femoral, L2-L4) and HS part of adductor magnus (tibial part of sciatic n., L4)

largest muscle in adductor group

adductor magnus; adductor and HS parts, double nerve inn.!

nerve supply to adductor group

all supplied by obturator n (L2-L4) except pectineus (femoral, L2-L4) and HS part of adductor magnus (tibial part of sciatic n., L4)

genu varum

bowleg; all pressure on inside of knee joint, patella moves laterally to weight-bearing line --> arthrosis of knee cartilages (but children commonly appear bowlegged for 1-2 years after starting to walk)

circumflex femoral arteries

branches of deep art. of thigh, or directly from femoral art. Encircles thigh to supply its muscles and proximal end of femur. Medial circumflex is especially important --> supplies most blood to femur head and neck, often torn in femoral neck fx/hip jt dislocation

linea aspera

broad rough line on posterior of femur

navicular

btn. talar head and 3 cuneiform bones; tuberosity projects medioinferiorly

largest and strongest foot bone?

calcaneus (articulates with talus superiorly, cuboid anteriorly)

femoral artery palpation and compression

can palpate pulse (midway btn ASIS and pubic symphysis, just inferior to inguinal ligament); can compress at this site in emergency to stop bloodflow through femoral artery and it's branches (eg. deep art. of thigh)

bumper tibial fx

caused when bar bumper strikes leg; often tears skin, bone fragment protruding --> compound fx

fx of lateral and medial melleoli

common in soccer/basketball players

deep fascia of leg

crural fascia (L. crus = leg)

chief artery of thigh

deep artery of the thigh

varicose veins, thrombosis, and thrombophlebitis

dilation of the great saphenous vein and its tributaries; pulmonary thromboembolism occurs in a few cases when a thrombus breaks free in a lower limb vein (check: painful calf? Longterm bedrest? Red flags!)

surface anatomy landmarks: PSIS

dimple (skin and underlying fascia attach to PSIS)

patellar fractures

direct blow, sudden quad contraction (proximal fragment pulled up with quad, distal remains with patellar ligament); fx in 2+ fragments

head of fibula

distal end

adductor canal contents

femoral artery and vein, saphenous n., nerve to VMO/vastus medialis

femoral hernia

femoral ring in ant. abdominal wall is usual originating site; often s. intestine loop. Hernial sac compresses contents of femoral canal (loose connective tissue, fat, lymphatics). Strangulation of hernia may occur (sharp rigid boundaries of femoral ring) --> death of tissues.

femoral triangle contents

from lat. to med.: NAVE (femoral NERVE; femoral sheath with femoral ARTERY and VEIN, and EMPTY space = femoral canal with femoral ring), plus branches of nerve, artery, and veign's proximal tributaries (eg. great saphenous and deep femoral); femoral artery and vein leave and enter adductor canal at apex

femoral vein location

inferior to inguinal ligament (by feeling femoral art.), NO tributaries at this level except for great saphenous vein 3 cm inferior --> varicose v. operations, important to ID great saphenous v. and not tie off femoral v. by mistake!

femoral triangle boundaries

inguinal ligament (sup., base of triangle), adductor longus (medially; NOT magnus), sartorius (laterally); apex = where medial border sartorius crosses lateral border adductor longus; roof = fascia lata, cribriform fascia, subcutaneous tissue, skin

superficial femoral vein

is NOT superficial, potentially lethal misnomer! Thrombosis of this vessel is potentially life-threatening. "Superficial" should not be used.

which femur epicondyle is larger?

medial

patellar dislocation

nearly always lateral dislocation, and more often in women (wider pelvis; and esp. ages 16-18)

gracilis

of adductor group: weakest, most superficial, only one that crosses knee jt

tibia's soleal line

on post/proximal part of tibial body; rough diagonal ridge line, runs inferomedially, approx. 1/3 of way down body

adductor tubercle

on superior border of medial epicondyle of femur

Rectus femoris

only muscle of quad that crosses 2 jts, to help iliopsoas flex hip

calcaneus medial tubercle

only one that rests on ground during standing

adductor hiatus

opening in aponeurotic distal attachment of adductor magnus; femoral art

surface anatomy landmarks: supracrestal plane (highest level of iliac crests)

passes thru L4/L5 intervertebral disc

muscles of anterior thigh/hip flexors

pectineus, ilipsoas, sartorius, TFL --> mainly femoral n. (L2-4), lumbar n. for psoas maj and min (L1-3), sup. gluteal n. (L4, L5)

perforating veins of thigh and leg

penetrate deep fascia at an oblique angle; superficial >> perforating >> deep. Are compressed by muscle contractions.

muscles of anterior thigh/knee extensors

quadriceps femoris (rectus femoris; vastus medialis, lateralis, intermedius), femoral n. (L2-4)

patellectomy

removal of patella for a comminuted fx --> quads need to exert more force to completely extend leg (recent techiques for patellar tendon repair to help minimize weakness of knee extension)

terminal cutaneous branch of femoral n

saphenous nerve

groin pull

strain/stretching/possibly some tearing of PAs of anteromedial thigh muscles (flexor and adductor group); sports involving quick starts

knee jerk

tests L2-L4; if reflex is normal, hand on patient's quad should feel contraction

talus articulates with....?

tibia, fibula, calcaneus, navicular

femoral nerve

L2, L3, L4; in the substance of psoas major muscle; enters deep to inguinal ligament, lateral to femoral vessels; sends branches to thigh muscles, and ant. femoral cutaneous n. to skin (ant. and especially medial thigh)

surface anatomy landmark: post. hip dimples

PSIS, line connecting is at S2 spinous process, passes thru center of SI jt