Lower Extremity Forum 2011
Describe the content of the subinguinal hiatus (space
between the inguinal ligament and the pelvic rim)
• Psoas major, iliacus, pectineus muscles
• Femoral artery, vein, nerve
– Femoral nerve not included in the femoral sheath
– Parent branch of artery is external iliac artery
• Lymphatics
• Lateral cutaneous nerve of thigh (lateral
femoral nerve of thigh)
– Located near the ASIS
Describe the borders and content of the femoral
triangle
• Base = inguinal ligament
• Medial border is adductor longus
• Lateral border is the medial part of the sartorius
muscle
• Floor is the pectineus, adductor longus
– And some of the iliopsoas
• Fascia latae forms the roof of the triangle
• Continues with fascial canal all the way to the adductor
canal
• Contains the femoral artery, nerve, vein, and
lymphatics
Describe the walls and content of the adductor canal
• Forms the apex of the femoral triangle
• Covered by fascia, roof is sartorius vasculoductor
membrane
• Comprised of fascia
– Contains femoral artery, femoral vein, saphenous nerve for
some of time (from femoral), genicular artery
• Descends medially down the thigh and shoots out
posteriorly thorough the adductor canal
– Goes through the adductor magnus muscle
– Opens into the popliteal fossa; now popliteal artery/vein
Describe the adductor hiatus
• Opening at the end of the adductor canal
– Deposits the femoral artery and vein into the
posterior portion of the leg via the opening at the
distal portion of the adductor magnus
• Will now become the popliteal artery/vein
Describe the borders and contents of
the popliteal fossa
• Superior Medial Border is the semitendonosus
• Superior Lateral Border is biceps emoris
• Inferior Medial Border is the medial head of the
gastrocnemius
• Inferior Lateral Border is the lateral head of the
gastrocnemius
• Plantaris muscle included on inferior lateral border
• Popliteal artery, vein, and Tibial nerve (AVN- aviation
up)
– Common fibular included? NOT QUITE
Describe the pathogenesis of the Baker’s cyst
and the prepatellar bursitis
• Buildup of synovial fluid behind the knee
– Caused by knee arthritis, meniscus injury,
herniation or tear of the joint capsule
– In popliteal fossa; hurts more during extension
– Impairs flexion and extension at the knee joint
• Inflammation and swelling of the prepatellar
bursa (lies right on top of patella)
– Housemaid’s knee; inability to flex the knee
– Repetitive kneeling will cause this
Describe the pathogenesis of the foot
drop
• Results from a non-functional tibialis anterior
– Common fibular nerve injury
• Passes behind the head of the fibula
– From head or neck fracture of the fibula
– Loss of dorsiflexion
– loss of sensation on the dorsum of the foot and
lateral aspect of the leg
– paralysis of all muscles in the anterior and lateral
compartments
Describe the unhappy triad and the Pott fracture
• MCL (tibio-collateral ligament), ACL, and medial
meniscus have been torn
– Usually results from impact to lateral portion of leg
• Fracture of distal fibula
– Often goes with a fracture of the medial malleolus or
rupture of the deltoid ligament
• Avulsion fracture is when medial malleolus comes off with it
– Torn anterior tibiofibular
– Comes from forced eversion of foot
Describe the cutaneous innervation of the lower
limb
• L2-L3 is from ass to knee, with L2-L4 coming
from the obturator on the inner thigh
• Page 346-347
Describe the borders of the femoral canal and
the symptoms of the femoral hernia
• Femoral canal borders:
– Do not need to know for exam
• Femoral hernias more common in women
because they have a larger superior pubic ramus
– Portion of abdominal cavity protrudes into femoral
canal (usually portion of the small intestine)
– Can be strangulated
– Poor blood supply occurs with death of nearby tissues
resulting (pinching femoral vein, artery perhaps)
Describe the pes anserinus
• Results from combinations of tendons of
gracilis, sartorius, and semitendonosus
– Found out at the medial border of the tuberosity
of the tibia
– Can be used to help repair a torn ACL
– SGT FOS
• Sart, grac, semitendinosus/femoral, obturator, sciatic
Describe the course of the saphenus nerve and
the descending genicular artery
• Great saphenous nerve branches off from the femoral
nerve and goes with it through the adductor canal
– DOES NOT go through the adductor hiatus
– Breaks medially to innervate medial side of leg
• Breaks through fascia between sartorius and gracilis
• Will supply skin on medial leg, knee, and foot
• Des. Genicular Artery arises from femoral artery in
adductor canal just before it passes adductor hiatus
– anastomose around the knee joint with other genicular
arteries (these come form the popliteal artery)
– Also gives rise to a saphenous branch
– Only genicular a. that comes off the femoral
Describe the venous circulation of the
lower limb
• Great saphenous drains the medial leg and thigh
anteriorly
– Wraps posteriorly around knee very briefly, then
comes back to the anteriomedial leg
– Pierces the femoral canal fascia to enter the canal
near the groin
• Small saphenous vein drains the posterior medial
leg and then enters into popliteal fossa
– Now named popliteal vein; goes through adductor
hiatus and becomes femoral vein
• Dorsal venous arch of foot gets the top of foot
Describe the anatomy of the lesser
and greater sciatic foramina
• Split in two by the Piriformis muscle
– The main point of reference for gluteal region
• Goes through the hole made by the ilium, sacrum, and
sacrotuberous and sacrospinous ligaments
• Part goes over the piriformis, another goes under piriformis
– OVER= superior gluteal artery, nerve, vein
– UNDER= sciatic nerve, inferior gluteal artery, vein, nerve,
posterior femoral cutaneous nerve, nerve to obturator internus
and gemellus superior, nerve to quadratus femoris/gemellus
inferior
• Lesser sciatic foramen goes under the ilium
– Obturator internus muscle tendon, and pudendal artery and
nerve also pass through this
Describe the ligaments supporting the
plantar arch
• Medial and lateral plantar arches at deep level
– Fall of medial arch results in flat foot
• Spring ligament involved
• Tibialis anterior and posterior/fibularis longus
support the arch on the lateral and medial
sides
– Ligaments are the static support
– Muscles are the dynamic support
Describe the arterial supply of the femoral head and
the possible fracture sites
• The lateral circumflex femoral artery and the
medial circumflex femoral artery (goes posterior)
– Some blood from superior and inferior gluteal aa.
– Artery of obturator internus also supplies some blood
– Medial circumflex femoral artery supplies more; main
supplier to head and neck of femur
• If broken, femur dies
• Possible fracture sites are the femoral neck,
intertrochanteric fossa, femoral shaft
– If neck not injured, blood supply could be safe