Week 7 Flashcards
The hip joint
Ball and socket synovial joint
Flexion, extension, abduction, Adduction , rotation, Circumduction
Tissue layers of the thigh
The skin
Superficial fascia
Deep fascia (fascia lata vs iliotibial tract)
Muscles
Femur
Inter muscular septa: medial, lateral, posterior
Neurovascular bundle
Lymph nodes
Fascial/ muscular compartments of the thigh
Anterior
Medial
Posterior
Each compartment has own general actions, own muscles, own nerve supply, common blood supply from profunda femoris
Anterior compartment
Knee extensors
(Quadriceps)
Femoral nerve neural roots L2,3,4
Femoral artery
Posterior compartment
Knee flexors and hip extensors
Hamstrings
Sciatic nerve neural roots L4,5 S1,2,3
Perforating branches or profunda femoris
Medial compartment
Thigh adductors
Adductors
Obturator nerve L2,3,4
Obturator artery
Knee joint
Synovial hinge joint allows some limited rotational movements
Supplied by femoral, Obturator, common peroneal and tibial nerves
Deep fascia
Investing leg is continuous with the deep fascia of thigh
Fascia lata becomes crural fascia
Crural fascia with tibia, fibula and interosseus membrane divide leg into 3 compartments
compartments of leg
Anterior: extensor: DP
Lateral: fibular: SP
Posterior: flexor:T
Each has own actions, muscles, blood and nerve supply
Anterolateral compartments of leg
Tibialis anterior
Assisted by extensor digitorum longus, extensor hallucis longus
Actions: dorsiflexion, inversion of foot
Nerve supply: deep peroneal nerve
Peroneus (fibularis) longus
Peroneus (fibularis) brevis
Both supplied by superficial peroneal or fibular nerve
Tendons bound by the fibular retinacular as they pass behind lateral malleolus
Their functions are to evert the foot and plantar flex the foot
Posterior compartment of the leg
Superficial and deep
superficial: gastrocnemius, soleus, plantaris together known as triceps surae
Share a common tendon of insertion
The tendo calcaneous= Achilles tendon, strongest tendon inserts into calcaneous of foot
Main action to plantar flex
Deep muscles: popliteus (act on knee), flexor halucis longus, tibialis posterior, flexor digitorum longus . Act on ankle and foot joint
The ankle
Lies inferiorly in upright position
It is the region of transition from the leg to the foot
Contains the ankle joint
Clinical importance
Site where limb length is measured
Arterial pulses of the limb are examined
Venous and lymph drainages of lower limb undergo challenges
Injuries occur regularly either as sprains or fractures
Layout bones, muscles and blood vessels shifts from vertical to horizontal axis
Bones of foot and arches
Talus
Calcaneous
Navicular
Cuboid
Cuneiform
Metatarsals
Phalanges
Neurological root values of ankle joint
Dorsiflexion: fibula division of sciatic (L4-5), same root values for big toe
Muscles: tibialis anterior assisted by extensor digitorum longus and extensor hallucis longus
Plantar flexion: tibial division of sciatic S1-2
Muscles: gastrocnemius and soleus assisted by tibialis posterior, flexor hallucis longus, flexor digitorum longus
Trauma and lower limb
Dislocation of hip joint -posterior dislocations
Femoral neck fractures
Damage cruciate ligament
Damage collateral ligament
Ankle joint injuries- Potts fracture
Compartment syndrome of Lower limb
Compartment syndrome
When perfusion pressure falls below tissue pressure in closed anatomical compartment , pressure in compartment too high
If left untreated leads to necrosis and ultimately death
Due to either decreased compartment size, increased fluid content: burns, intra-arterial injection, infiltrated infusion, haemorrhage, envenomation
Follows path of ischaemic injury
An introduction of excess fluid or extraneous constriction increases pressure and decreases tissue perfusion until no O2 is available for cellular metabolism
What is a plexus
A plexus is a collection of nerve fibres from one source that form ‘new’ nerves with specific targets/destinations
Either somatic or visceral
Lumbosacral plexus forms from the anterior rami of spinal nerves L1-S4
What does lumbosacral plexus form from
Anterior rami of spinal nerves L1-S4
Whats a ramus
The root comes first then the branch- ramus
Ramus= branch
The lumbosacral plexus
Consists of two smaller plexuses: lumbar plexus and sacral plexus
Sits on the posterior abdominal wall of abdomen and pelvis
The lumbar plexus
Derived from roots T12-L4
Forms inside psoas major muscle
I (twice) get laid on Fridays
Iliohypogastric (laterally)
Ilioinguinal (laterally)
Genitofemoral (emerges anteriorly from psoas)
Lateral cutaneous nerve of thigh (laterally)
Obturator (emerges medially to psoas)
Femoral (laterally)
Nerve roots of nerves of lumbar plexus
Iliohypogastric- L1
Ilioinguinal- L1
Genitofemoral- L1 +L2
Lateral cutaneous nerve of thigh- L2 +L3
Obturator- L2 +L3+L4
Femoral- L2 L3 L4
2 from1 2 form 2 2 from 3
Lumbar plexus points
Anterior rami of spinal nerves L1-L4
Also receives input from T12 (subcostal nerve)
Emerge in relation to psoas major muscle anterior, medial, lateral
Motor and sensory modalities
Nerves in the lumbar plexus are either sensory only or have mixed motor and sensory
None are motor only
What nerve of the lumbar plexus is sensory only
Lateral cutaneous nerve of thigh
Rest of the nerves are all mixed
Sacral plexus
L4-S4 lumbosacral trunk from L4/5 part of sacral plexus , ventral rami
Lies superficial to piriformis muscle
The piriformis muscle inserts into the greater trochanter of the femur
Superior gluteal nerve, inferior gluteal nerve, sciatic nerve, posterior femoral cutaneous nerve, pudendal nerve
Nerves either exit via greater sciatic foramen above (sup gluteal) or below piriformis
Or exit via greater sciatic foramen but loop around sacrospinous ligament and come back into pelvis via lesser sciatic foramen (pudendal and nerve to Obturator internus)
Which muscles does the superior gluteal nerve lie between
Lies on gluteus minimus and deep to gluteus medius
What structures does superior gluteal nerve innervate
Gluteus minimis
Gluteus medius
Tensor fascia lata
What innervates the gluteus maximus
Inferior gluteal nerve
What nerves arise from the sciatic nerve divide
Tibial and common peroneal (fibular) nerve
Tibial nerve is anterior rami
Fibular nerve is dorsal rami
What muscles does the tibial nerve innervate
Posterior compartment of thigh except short head of biceps femoris which is femoral nerve
Adductor Magnus
Posterior compartment of leg
All muscles in sole of the foot
Sensory component: posterolateral leg and sole
What does the common peroneal/fibular nerve innervate
Short head of biceps femoris
Anterior compartment of the leg
Lateral compartment of the leg
Extensor digitorum brevis
Sensory- anterolateral leg and Dorsum of foot
What do you see with damaged common peroneal nerve
Can’t lift foot because it supplies extensor digitorum brevis
Get foot drop
What does the posterior cutaneous nerve of the thigh innervate
Sensory innervation
Posterior thigh, posterior leg and part of the perineum
What does the pudendal nerve supply
Motor- skeletal muscle: perineum, external urethral and anal sphincter, levator ani muscle
Sensory- penis, clitoris and most of the perineal skin
Nerve roots of sacral plexus nerves
Superior gluteal- L4-S1
Inferior gluteal- L5-S2
Posterior cutaneous nerve- S1-S3
Pudendal- S2-S4
Sciatic- L4-S3
Obturator externus and internus
Obturator externus- lumbar plexus
Obturator internus- sacral plexus L5-S2
Where to do injection in buttocks
Avoid sciatic nerve
Superior outer quadrant is safe to inject
Sciatic inferior inside quadrant
What is sciatica
Term used to describe symptoms that present within distribution of sciatic nerve
Pain over aspects of thigh or leg
Numbness/tingling of aspects thigh or leg paresthesia
Weakness of movement of the knee and ankle
Causes: disc prolapse- intervertebral disc, muscle entrapment from piriformis muscle, bony spinal pathology, osteoarthritis
Treatment: physical therapy, NSAIDS, local steroid injections, surgical repair (microdiscectomy, laminectomy)
Stenosis
Narrowed spinal canal
Spondylolisthesis
Vertebra slips forward
Radiculopathy
Injury or damage to nerve roots in area where they leave the spine
Referred to as a punched nerve
Spondylitis
Arthritis- long term inflammation of joints of spine
Severe chronic pain
