W5 Lower limb Flashcards
• Leg general
o Three compartments separated by interosseous membrane and intermuscular septa o Muscles of the leg plantarflex and dorsiflex the foot o Invert (supinate) and evert (pronate) o Extend and flex toes
• Anterior compartment
o 4 muscles: tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularus teritus o Deep fibular nerve o Anterior tibial artery o Dorsiflexion and inversion of foot o Extension of toes
• Tibialis anterior
o Anterior compartment
o Dorsiflexes and inverts foot
o Deep fibular nerve
• Extensor hallucis longus
o Anterior compartment
o Dorsiflexes foot and extends great toe
o Deep fibular nerve
• Extensor digitorum longus
o Anterior compartment
o Dorsiflexes foot and extends lateral four toes
o Deep fibular nerve
• Fibularus tertius
o Anterior compartment
o Dorsiflexes foot
o Deep fibular nerve
• Lateral compartment
o 2 muscles
o Superficial fibular nerve
o Fibular artery
o Eversion and plantar flexion
• Fibularis longus
o Lateral compartment
o Plantarflexes and everts foot
o Superficial fibular nerve
• Fibularis brevis
o Lateral compartment
o Everts foot
o Superficial fibular nerve
• Posterior compartment
o 3 superficial muscles o 4 deep muscles o Tibial nerve o Posterior tibial artery o Plantar flexion and inversion of foot o Flexion of toes
• Gastrocnemius
o Posterior compartment
o Superficial
o Plantarflexes foot and flexes knee
o Tibial nerve
• Soleus
o Posterior compartment
o Superficial
o Plantarflexes foot
o Tibial nerve
• Plantaris
o Posterior compartment
o Superficial
o Plantarflexes foot and knee
o Tibial nerve
• Tibialis posterior
o Posterior compartment
o Deep
o Plantarflexes and inverts foot
o Tibial nerve
• Flexor digitorum longus
o Posterior compartment
o Deep
o Flexes lateral four toes and inverts foot
o Tibial nerve
• Flexor hallucis longus
o Posterior compartment
o Deep
o Flexes great toe and inverts foot
o Tibial nerve
• Popliteus
o Posterior compartment o Deep o Stabilizes and unlocks knee joint o (rotates femur laterally from fixed tibia) o Tibial nerve
• Lumbar plexus
o Anterior rami of L1-L4
• Sacral plexus
o Anterior rami of L4-S5
• Lumbosacral plexus
o Combo of lumbar and sacral
o Provide sensory and motor innervation to lower limb
• Femoral nerve
o L2, L3, L4
o Motor branches to anterior compartment muscles and pectineus
o Two sensory branches: anterior cutaneous nerve to the thigh and saphenous nerve
o Saphenous nerve goes through adductor canal to supply sensation to medial leg and malleolus
• Obturator nerve
o L2, L3,L4
o Motor branches to medial compartment of thigh and adductor magnus
o Cutaneous branch to skin above medial side of knee
• Sciatic nerve
o L4, L5, S1, S2, S3
o Divides into tibial and common fibular nerves proximal to popliteal fossa (behind knee)
• Common fibular nerve
o L4, L5, S1, S2
o Branch of sciatic nerve
o Splits into superficial fibular nerve and innervates lateral compartment of leg and overlying skin of foot)
o And deep fibular nerve that innervates anterior compartment of leg and overlying skin of leg and between great and 2nd toe
• Tibial nerve
o L4, L5, S1, S2, S3
o Innervates posterior compartment of leg and is sensory to overlying skin and plantar surface of the foot
• Obturator canal
o Through obturator foramen passing inferior to the superior pubic ramus
o Obturator nerve passes through here
• Greater sciatic foramen
o Below piriformis muscle: Sciatic nerve Inferior gluteal nerve Posterior femoral cutaneous nerve Nerves to obturator internus and quadratis femoris
o Above piriformis muscle
Passing between gluteus medius and minimus
Superior gluteal nerve
• Lesser sciatic foramen
o Pudendal nerve passes from gluteal region into perineum
• Inferior to inguinal ligament
o Femoral nerve
o Femoral branch of genitofemoral nerve
o Lateral cutaneous nerve of thigh
• Obturator sensory endpoint
o Medial thigh above the knee
• Femoral sensory endpoint
o Medial malleolus
• Tibial sensory endpoint
o Lateral malleolus (sural nerve)
• Superficial fibular sensory endpoint
o Dorsum of the foot
• Deep fibular sensory endpoint
o Between the first two toes
• Deep fibular nerve lesions
o Anterior compartment syndrome
o Anterior tarsal tunnel syndrome at the extensor reticulum
• Anterior compartment syndrome
o Deep fibular nerve
o Drop foot
o Inability to dorsiflex the foot causing patient to use high steppage gait to walk
o Sensory loss in triangular region between the first and second toes
• Anterior tarsal tunnel syndrome at the extensor reticulum
o Deep fibular nerve
o Weakness in toe extension
o Sensory loss in triangular region between the first and second toes
• Superficial fibular nerve lesions
o High lesion at the head of fibula
o Low lesion with lateral ankle sprain
• High lesion at the head of fibula
o Superficial fibular nerve
o Loss of foot eversion and or subtalar pronation and ankle stability
o Loss of sensation on lateral leg, lateral malleolus and dorsum of the foot
• Low lesion with lateral ankle sprain
o Superficial fibular nerve
o No weakness
o Loss of sensation on lateral leg, lateral malleolus and dorsum of the foot
• Tibial nerve lesions
o Popliteal region from knee trauma such as dislocation or a blow
o Tarsal tunnel entrapment at the medial malleolus
• Popliteal region from knee trauma such as dislocation or a blow
o Tibial nerve
o Unable to plantarflex or invert/supinate foot effecting gait
o Loss of toe flexion, abduction and adduction
o Patient will not push off
o Loss of sensation on the posterolateral aspect of lower one third of leg, lateral malleolus and lateral border of the foot, heal and sole of foot and toes
• Tarsal tunnel entrapment at the medial malleolus
o Tibial nerve
o Loss of intrinsic foot function
o Loss of sensation on the anterior sole of the foot and plantar surface of the toes
• Femoral nerve lesion
o Anterior dislocation of the femur from trauma or injury from pelvic of hip surgery, abdominal or hernia repair
o Inability to flex the thigh or extend the knee
o Will be locked in extension of knee
o Loss of sensation to medial side of leg, medial malleolus (saphenous nerve) or medial knee (medial cutaneous nerve)
• Obturator nerve lesion
o Compression in the obturator tunnel from pelvic fracture or injury, pregnancy or tumor
o Inability to adduct the hip
o Weakness of knee flexion (gracilis) and hip external rotation (obturator externus)
o Difficulty with gait exhibiting an externally rotated foot
o Loss of sensation to medial patch of skin just above knee
o May also complain of groin or pubic symphysis pain
• Femoral artery
o Continuation of external iliac artery in the abdomen
o Becomes femoral when it passes under inguinal ligament and enters femoral triangle in the anterior thigh
o Supplies most of the thigh and all of the leg and foot
• Femoral triangle
o Bordered by inguinal ligament superiorly
o Lateral border is sartorious muscle
o Medial border is adductor longus
o Femoral nerve, artery, vein, and lymphatics pass through here under inguinal ligament into the triangle
o Femoral sheath covers vein, artery, and lymphatics
o Femoral pulse can be felt in femoral triangle just inferior to inguinal ligament and midway between anterior aspect of iliac spine and pubic symphysis
• Other vessels supplying gluteal region
o Superior and inferior gluteal arteries
o Obturator artery in medial compartment of thigh
o All are branches of the internal iliac artery in pelvis
o Follow the path of their nerves
• Collateral circulation of hip joint
o Anastomoses between branches of deep femoral (medial and lateral femoral circumflex and 1st perforating branch), branches of obturator artery and branches of superior and inferior gluteal arteries
o Insufficiency of medial femoral circumflex artery is most common cause of avascular necrosis of the femoral neck and head
• Collateral circulation of knee joint
o Anastomoses of descending branch of lateral femoral circumflex and descending genicular branch of femoral artery, genicular branches from popliteal artery, circumflex fibular artery and recurrent branches of popliteal artery
o Descending genicular branch of femoral artery branches just before femoral artery enters adductor canal at the adductor hiatus
o Form a robust anastomotic network around the joint
• Compartment syndrome
o Deep or investing fascia (fascia lata) do not expand so swelling in the compartment leads to increased pressure which will compress the muscles, blood vessels, and nerves
o Acute: caused by trauma such as car accident, crush injury, surgery
o Chronic: repetitive activities such as running, pressure increases during activity
o Most common in leg and forearm
o Relieved by cutting skin and fascia (fasciotomy)
• Ankle joint
o Synovial hinge joint between talus, tibia and fibula
o Allows for dorsiflexion and plantarflexion of the foot on the leg
o Distal ends of fibula and tibia are anchored by medial (deltoid) and lateral ligaments to create a deep socket for upper body of the talus
• Lateral ligament
o Composed of three ligaments
o Most commonly sprained (foot inversion)
o Posterior talofibular ligament
o Anterior talofibular ligament (most commonly injured)
o Calcaneofibular ligament
• Medial (deltoid) ligament
o Four parts based on inferior points of attachment
o Tibionavicular part
o Tibiocalcaneal part
o Posterior tibiotalar part
o Anterior tibiotalar part
o Sprain of ligament occurs by foot eversion
genitofemoral
- lumbar plexus
- L1, L2
lateral femoral cutaneous
- lumbar plexus
- L2, L3
femoral
- lumbar plexus
- L2, L3, L4
obturator
- lumbar plexus
- L2, L3, L4
superior gluteal nerve
sacral plexus
L4, L5, S1
inferior gluteal nerve
sacral plexus
L5, S1, S2
sciatic
sacral plexus
L4, L5, S1, S2, S3
posterior femoral cutaneous
sacral plexus
S1, S2, S3
