Popliteal Fossa and Leg Flashcards
where do popliteal abscesses spread?
superiorly and inferiorly b/c of the toughness of popliteal fascia
palpation of popliteal pulse
can be difficult - Pt in prone position w knee flexed - feel in inferior part of the fossa where popliteal artery is related to tibia
what does weakening or loss of popliteal pulse indicate?
femoral artery obstruction
popliteal aneurysm
abnormal dilation of all or part of the popliteal artery - causes edema and pain in popliteal fossa
how to distinguish popliteal aneurysm from other masses
palpable pulsations (thrills) and abnormal arterial sounds (bruits) detected w/ stethoscope
referred pain from popliteal aneurysm
compresses tibial nerve - referred pain to skin over medial aspect of calf, ankle, or foot
arteriovenous fistula
communication b/w an artery and a vein
how can blood bypass a ligated femoral artery to reach the popliteal fossa?
through the genicular anastamosis
causes of injury to tibial nerve
- posterior dislocation of the knee joint
- deep lacerations in fossa
severance of tibial nerve
- paralysis of flexor muscles in the leg and intrinsic muscles in the sole of the foot
- can’t plantarflex ankle or flex toes
- lose sensation on sole of foot
containment and spread of compartmental infections in leg
- in ant and post: spreads distally
- in lat: can ascend proximally into the popliteal fossa
shin splints
edema and pain in the area of the distal 2/3 of the tibia from repetitive microtrauma of the tibialis anterior (mild form of anterior compartment syndrome)
unique features of human foot
stand more pronated b/c of:
- medial migration of distal attachment of fibularis longus across sole of foot
- development of a fibularis tertius attached to base of 5th metacarpal
what is the most common nerve injured in the lower limb?
common fibular nerve - due to superficial position
severance of common fibular nerve
flaccid paralysis of all muscles in the anterior and lateral compartments of the leg (dorsiflexors of ankle and evertors of foot)
footdrop
loss of dorsiflexion of ankle
3 ways to compensate for a limb that is too long
- waddling gait
- swing-out gait
- steppage gait
sound associated with footdrop
clop - due to foot slapping on the ground - more shock to forefoot and up tibia to knee
sensation loss w/ common fibular nerve lesion
- anterolateral aspect of leg
- dorsum of foot
ski boot syndrome
deep fibular nerve entrapment -where nerve passes deep to the inferior extensor retinaculum and extensor hallucis brevis (also due to tight shoes)
what can produce recurrent stretching of the superficial fibular nerve?
chronic ankle sprains
calcaneal tendinitis
inflammation of Achilles tendon
most severe acute muscular problem of leg
rupture of Achilles (calcaneal) tendon
- no plantarflexion against resistance
- excessive passive dorsiflexion
- bruising in malleolar region
- lump in calf (shortened triceps surae)
calcaneal tendon reflex
= ankle jerk reflex = triceps surae reflex
- normal: plantarflexion of ankle joint
- tests S1 and S2 nerve roots
stance during absence of plantarflexion
rotated foot as far laterally as possible - to allow a more effective push off through hip and knee extension exerted at midfoot
tennis leg
gastrocnemius strain - painful acute injury from partial tearing of the medial belly of the gastrocnemius at/near it’s musculotendinous jxn
calcaneal bursitis
retro-achilles bursitis - inflammation of the deep bursa of the calcaneal tendon
- pain posterior to heel
- caused by excessive friction on the bursa as tendon continuously slides over it
musculovenous pump
- blood pumped superiorly in deep veins by contraction of calf muscles
- improved by deep fascia that invests muscles like an elastic stocking
accessory soleus
appears as a distal belly medial to the calcaneal tendon - can cause pain and edema during prolonged exercise
palpation of posterior tibial pulse
b/w the posterior surface of the medial malleolus and the medial border of the calcaneal tendon - have Pt invert foot to relax retinaculum
why are both posterior tibial pulses taken simultaneously?
for equality of force - needed for diagnosis of occlusive peripheral arterial disease
intermittent claudication
presents w/ leg pain and cramps during walking that disappears w/ rest - from ischemia of leg muscles caused by narrowing or occlusion of the leg arteries
