Lower Extremities (foot, ankle, knee, hip) Flashcards
what is the typical etiology of an achilles tendon rupture?
kick to the post calf, males, missed 25% of time
what are the two endpoints of the wtbearing axis?
femoral head to talar dome
what is the physiological heel position?
valgus, varus when walking
what predisposes people to rolling ankles?
naturally varus ankles
what joint is responsible for dorsi/plantar flexion of the foot?
tibiotalar joint
what joint is responsible for inversion/eversion of the foot?
subtalar joint
should you inject steroids into the achilles tendon?
no
what tendons make up the achilles?
gastrocnemius and soleus
why is the achilles tendon slow healing?
watershed area at calcaneous
what is the most effect Dx of achilles rupture?
thompson test
no plantarflexion of ankle with squeezing calf
ability to plantar-flex is not good method (FDL, Tib Post, FHL, Plantaris, Peroneus Longus can also plantar-flex)
what is the best Tx for achilles rupture?
plantarflex splint for 1-2 wks, refer to surgery if needed
high risk DVT, follow up
rehab
what is the typical mechanism of ankle sprains?
inversion and plantarflexion
what ligament is the most commonly torn in ankle sprains?
ATFL
according to the ottawa ankle rules, when is an XR needed in ankle sprains?
bony tenderness of lateral & medial malleoli, inability to bear wt, age >55
what is the Tx for ankle sprains?
RICE, functional rehab (months)
when would you order an MRI in ankle sprains?
usually people
suspected talar osteochondral injury, peroneal tendon damage
DDx for persistant ankle sprain (2-3 mo):
bony injury, tendon injury, ligament injury
what type of fractures usually happen in the ankle?
rotational
pilon fractures from axial load
what Hx elements indicated an ankle fracture?
sounds like sprain but unable to bear wt, or reported dislocation
when is surgery needed in ankle sprains?
displaced LM fracture, bimalleolar/trimalleolar fracture
avulsive lateral malleoli fractures are on the same spectrum as ankle sprains and can be treated like them
what is the biggest risk factor for bunions (hallux valgus)?
genetics
medial deviation of first metatarsal and lateral deviation and pronation of hallux
what is the firstline Tx for bunions?
accommodative footwear
when is surgery indicated in bunions?
pain, progression, transfer metatarsalgia (secondary pain)
what is hallux rigidus?
arthritis in big toe MTP joint
trauma, idiopathic
may coexist with bunions
osteophytes
what Tx are given for HR?
rest, NSAIDs, activity mod. footwear mod, mortons extension shoe inserts
cortisone
surgical options avail
in what cases are flatfeet (Pes planovalgus) problematic?
pediatric stiff flatfeet (bony fusions), progressive, acquired flatfeet in adults
what are the dynamic stabilizers of the foot?
Tibialis posterior tendon (key), spring ligament, deltoid ligament, plantar fascia
what symptoms would be seen in TPT dysfunction?
pain in medial foot first, then lateral, static stabilizers fail first
test with single limb heel rise
Tx with RICE, NSAID, ankle supports, no cortisone, surgery
what does healthy articular cartilage need?
attachment to healthy subchondral bone (if detached, detect as foreign material and sets off inflammation), healthy synovial fluid in joint
what causes abnormal forces on cartilage in joint?
instability, malalignment, obesity
what are the hallmarks of degenerative joint disease (DJD)?
increased water, decrease chondrocytes and proteoglycan, abnormal collagen
what are the primary causes of arthritis?
degenerative, autoimmune
what are the XR features of arthritis?
joint space narrowing, subchondral sclerosis, cysts, osteophytes
what does varus knees indicate?
significant OA
what is the trendelenberg sign?
limp in arthritis
what are common signs of hip arthritis?
limb length discrepancy, muscle atrophy
in classical OA of hip, which motion is lost first? A. Flexion B. Abduction C. Internal rotation D. External rotation
internal rotation
what does the crescent sign indicate?
fracturing femoral head
what is the last stage of hip arthritis?
femoral head collapse and secondary arthritis
can arthroscopy fix arthritis?
No
in setting of head collapse, total hip replacement and decompression
what is the requirement for knee realignment?
joint space
what causes knee replacement failure?
infection, loosening (infection or aseptic), plastic wearing out, trauma
revision arthroplasty has higher risk of DVT/PE, failure, stiffness, etc.
what is the cause of aseptic loosening?
obesity
what is the gold standard for advanced AVN?
total arthroplasty
what’s the most common mechanism of ACL injury?
non-contact pivot external
what is a chronic risk of torn ACL?
arthritis due to bone shift (instability)
what Tx can be done for an ACL tear if the pt is too young for knee replacement?
stabilizing plates
what are indications for urgent MRI in acute soft tissue knee problems?
hemarthrosis in the skeletally immature, multiply ligamnet injury, patellar dislocation/osteochondral fractures, discordance between Hx and PE, comorbidities that contraindicate XR, inability to distinguish locked and stiff knee
can a locked knee perform flexion?
yes
what can cause a locked knee?
meniscus tear, torn ACL, loose body
if the joint is swollen immediately after injury, what is the fluid made of?
blood
what test can be used to Dx a dislocated knee cap?
apprehension sign w varus/valgus
what is the typical mechanism of patella/quad tendon rupture?
EC loading
how would a meniscus tear present?
no swelling/bruising, tenderness at joint line
what does the MCL prevent?
genu valgus
what is the Lachman’s test used for?
ACL/PCL function test
what common radiographic feature can be found on ACL tears?
segond fracture from avulsion
what is a risk factor for ischemia in knee dislocation?
proximity to popliteal artery
what is hemarthrosis?
bleeding in joint capsule
what’s the difference between acute and chronic MSK injuries?
acute-trauma, energy input to tissue> absorbed
chronic-overuse, inadequate recovery between stress
what are the most common areas of stress fractures?
lower extremity (tibial and metatarsal)
what do you Dx stress fractures?
TBS
why are stress fractures in the anterior tibia harder to tx?
higher rate of delay and non union
what part of the LE is most affected by periostitis?
medial tibia
how should quadricep contusions (crush injury) be managed?
immobilize in flexion to prevent stiffness, compression to prevent hematoma
what is a potential complication of muscle strain/tear?
myositis ossificans secondary to muscular bleed
what types of tendon tears are indicative of urgent surgery?
young RC tear, distal biceps tendon, quads/patellar tendons, achilles/peroneal/post tib
what disorder is indicated by lateral knee pain worse with downhill, “catching feeling”, and lack of knee swelling?
ITBS
where is acute post trauma bursitis likely to occur?
olecranon or pre-patellar area
what causes frozen shoulder?
capsule synovitis and fibrosis
what is synovial fluid
ultrafiltrate of blood plasma
lubrication, nutrition, shock absorption
10cc
DDx of hemarthrosis
bleeding disorder (hemophilia A,B, VWD) fracture (patella, femoral condyle, tibial plateau) extensor mechanism injury meniscus tear ligament tear
Ottawa knee rules include
Age 55 or older Isolated tenderness of patella or tenderness of head of fibula or inability to flex >90 degrees or inability to bear weight both immediately and in the emergency department for 4 steps
describe patellar dislocation (extensor mechanism injury)
Hx: pop, painful, deformity, risk factors of valgus, F>M, ‘double jointed’
Tx: imaging often normal, usually non-operative (PT + bracing)
describe quadriceps/patellar tendon rupture (extensor mechanism injury)
Hx: pain, pop, difficulty weightbearing, eccentric contraction, risk factors of steroids, Abx, age, pre-existing tendonitis, uremia
Dx: straight leg raise, XR,
Tx: surgical correction
mechanism of injury for tendon rupture; which of the following is incorrect?
Lunging for ball in squash game (Achilles)
Catching a TV that’s falling off a shelf (biceps)
Clean and jerk (quadriceps)
Landing from a basketball lay-up (Achilles)
Lifting a heavy tire into the back of a pickup truck (biceps)
Lifting a heavy tire into the back of a pickup truck (biceps)
function of meniscus
stability, lubrication and nutrition, axial load transfer, shock absorption
describe bucket handle tear
tear along the length, leaves handle-like flap
Hx: pop, twisting mechanism, no bruising, PMT along joint line
Dx: Mcmurray/Apleys
MRI
Tx: non-op if no pain, transplant from cadavers
Medial collateral ligament (MCL) prevents ____ and can be tested with ______
Medial collateral ligament (MCL) prevents valgus and can be tested with valgus stress at 0 and 30 degrees
Lateral collateral ligament (LCL) prevents ____ and can be tested with ______
Lateral collateral ligament (LCL) prevents varus and can be tested with varus stress at 0 and 30 degrees
Anterior cruciate ligament prevents ____ and can be tested with ______
anterior translation, rotation
Anterior drawer test, pivot shift
Posterior cruciate ligament prevents ____ and can be tested with ______
posterior translation, posterior drawer/Lachman
what is a segond fracture?
avulsion fracture (soft tissue structures tearing off bits of their bony attachment) of the lateral tibial condyle of the knee
healing potentials of knee ligaments
ACL has no potential to heal
MCL & LCL have better blood supply and are surrounded by synovial fluid
Tx for ligament tears
Crutches; collaterals: 4-6 weeks, cruciates: for comfort purposes Bracing; collaterals: 4-6 weeks, cruciates: no, put PCL is exception Surgical reconstruction (ACL)
define valgus
bone segment distal to a joint is angled outward, that is, angled laterally
define varus
excessive inward angulation (medial angulation) of the distal segment of a bone or joint
composition of articular cartilage (joint)
65-80% water
Type II collagen
proteoglycans
chondrocytes
Tx for knee arthritis
NSAID, cortisone, visco-supplementation, analgesic, walking aids, weight loss, PT, orthotics, conditioning
severe: arthroscopy
Etiology of avascular necrosis
SCD, viral, bacterial, fracture, dislocation, EtOH, Gaucher’s, hyperlipidemia, steroid therapy, MM, irradiation induced, Caisson’s disease (nitrogen bubble)
