Anatomy - Lower Limb Flashcards
Which nerves arise from Lumbar plexus?
6 Major Nerves
“I TWICE Get Laid On Fridays”
1) Iliohypogastric Nerve
Roots : L1
Motor: Internal oblique and transversus abdominis
Sensory: Innervates the posteriolateral gluteal skin
2) Ilioinguinal Nerve
Roots: L1
Motor: Internal oblique and transversus abdominis
Sensory: Skin on anteromedial thigh +
males – root of penis and anterior scrotum, females – skin over pubis and labia majora
3) Genitofemoral Nerve
Roots: L1,2
Motor : Cresmasteric muscle – Genital branch
Sensory:
Genital branch
• Skin of mons pubis and anterior scrotum in males, Labia majora in females.
Femoral branch
• Skin of upper anterior thigh
4) Lateral Cutaneous Nerve of the Thigh
Roots: L2, L3
Motor: None
Sensory: Anterior and lateral thigh down to knee
5) Obturator Nerve
Roots: L2, L3, L4
Motor: Innervates muscles of medial thigh
obturator externus, adductor longus, adductor brevis, adductor magnus and gracillis
6) Femoral Nerve
Roots: L2,L3,L4
Motor: Muscles of anterior thigh – Iliacus, Pectineus, Sartorius and Quadriceps Femoris
Sensory: Skin on the anterior Thigh and Medial leg
o Anteromedial thigh – Anterior cutaneous branches of the femoral nerve
o Saphenous nerve – Medial leg and foot
What Nerves arise from The Sacral Plexus?
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1) Superior Gluteal Nerve (L4,L5,S1)
o Motor – Glut. Minimus, Glut. Medius and Tensor fascia lata
o Sensory – None
2) Inferior Gluteal Nerve (L5,S1,S2)
o Motor - Gluteal Maximus
o Sensory- None
3) Sciatic Nerve (L4,L5,S1,S2,S3)
o Tibial portion
• Motor – Muscles of posterior compartment of thigh (except biceps femoris)
• Sensory- Skin in posterolateral leg, lateral foot and sole of the foot
o Common Peroneal
• Motor – Short head of biceps femoris, all muscles in anterior and lateral leg + extensor digitorum brevis
• Sensory- Skin lateral leg and dorsum of foot
4) Posterior Femoral Cutaneous ( S1,2,3)
o Motor- None
o Sensory – Innervates skin on posterior surface of the thigh and leg + skin of perineum
5) Pudendal Nerve (S2,3,4)
o Motor – Skeletal muscles of perineum, EUS, EAS, Levator Ani
o Sensory – Penis, clitoris and most of skin of the perineum
What are extracapsular ligaments of the hip joint and their attachments?
Iliofemoral – Y shaped and twisted
• ASIS to intertrochanteric line
Pubofemoral
• Iliopubic junction inserts to medial aspect of capsule
Ischiofemoral
• Ischium and inserts into the base of the greater trochanter
What structures attach to GT/ LT
- Gluteus medius
- Glut. Minimus
- Piriformis
- Superior Gemili + Inferior Gemili
- Obturator externus
- Obturator internus
LT- Iliopsoas
Name the muscles that attach to Linea Aspera
Pectineus, Adductor magnus (Adductor portion) , Adductor longus, Adductor brevis
Name the structures that attach to ASIS and AIIS
- ASIS: Tensor fasciae latae, Sartorius, Inguinal ligament
* AIIS: Iliofemoral ligament, Staight head of rectus femoris
Structures attaching to the IT band
- Thickening of fascia latae
- IT track blends to become band
- Glut Maximus
Function of IT band
Stabilises knee on extension during the gait cycle
Blood supply to the hip joint
• Suppled by 2 important anastomoses – Cruciate and Trochanteric
• Cruciate anastomoses
- IGA, medial and lateral circumflex femoral, 1st perforating artery from Profunda Femoris and posterior branch of obturator artery
• Trochanteric anastomoses – Main blood supply to head of femur
- Superior gluteal artery and medial and lateral superior circumflex arteries
Blood Supply to the neck and head of femur
Retinacular arteries - Ascending cervical branches of lateral circumflex femoral artery contribute to sub synovial arterial ring and the medial circumflex artery supplies the weight bearing posterior superior aspect
Extracapsular ring of anastomosis - Ascending cervical vessels also contribute to the extracapsular ring of anastomosis at the bease of the femoral neck.
Artery of ligamentum teres - branch of obturator
Interossous blood supply
Perforating arteries of profunda femoris
What is the clinical relevance of the blood supply to neck and head of femur
Intracapsular fractures of the neck and femur disrupt retinacular vessels - Disrupt vascular supply, avascular necrosis
Structures passing through the greater sciatic foramen above the piriformis
- Superior Gluteal Nerve
* Superior Gluteal Vessels
Structures passing through the greater sciatic foramen below the piriformis
- Inferior gluteal nerve
- Inferior gluteal vessels
- Pudendal nerve
- Sciatic nerve
- Posterior femoral cutaneous nerve
- Nerve to obturator internus
- Nerve to quadratus femoris
Structures passing through lesser sciatic foramen
- Pudendal nerve – (Leaves GSF to re-enters foramen via the lesser sciatic foramen)
- Internal pudendal artery and vein
- Obturator internus tendon
- Nerve to obturator internus
Main flexors of the hip ?
- Psoas and Iliacus muscles are main hip flexors
* Pectineus, Rectus femoris, adductor longus and sartorius contribute
Nerve Supply to the main flexor of the hip
• Psoas Major – L1,L2,L3 Ventral rami
• Ilacus, rectus femoris and sartorius – Femoral Nerve (L2,3,4)
Pectineus -Femoral (Accessory Obturator in 20% )
Name the external rotators of the hip
- Piriformis
- Superior and inferior gemilli
- Obturator internus and externus
- Quadratus femoris
- Gluteus Maximus
Garden Classification
- Garden 1 – Incomplete, No displacement
- Garden 2 – Complete, undisplaced
- Garden 3 – Complete, partially displaced
- Garden 4 – Complete, completely displaced
Lateral approach to hip
- Division of Tensor Fascia Latae, gluteus medius, and minimus to expose femoral neck
- Gain further access by detaching Greater Tuberosity attachments
Anterior approach to hip
- Incision Anterior half of iliac crest towards direction of lateral patella
- Head of Rectus femoris is divided and reflected
- Gain further access by detaching GMed and GMin from ilium
Posterior approach to hip
- Curvilinear incision over PSIS to Greater trochanter
* Superior gluteal nerve and Sciatic nerve at risk
Name the boundaries of the femoral triangle
- Lateral border: Medial border of Sartorius
- Medial border: Medial border of Adductor longus
- Superior border: Inguinal Ligament
- Floor: Pectinues, Iliacus, psoas major
- Roof: Fascia lata, Subcutaeous tissue and Skin
Name Contents of femoral triangle
- From lateral to medial
- Femoral nerve
- Femoral Arteryguin
- Femoral Vein
- Femoral Canal and lymph nodes
Contents of Femoral Sheath
• Femoral Artery, Femoral Vein, Femoral Canal
Borders of Femoral Canal
- Medial border – Lacunar ligament
- Lateral- Femoral vein
- Anterior- Inguinal ligament
- Posterior- Pectineal ligament + muscle
What is the femoral Ring?
- Opening of femoral canal at the superiorly abdominal end
* Femoral hernias – inferolateral to pubic tubercle (FV laterally, Lacunar medially)
Describe course of femoral artery
- External iliac artery becomes the common femoral artery at the level of the inguinal ligament (mid-inguinal point)
- Approx. 4cm into the femoral triangle, the common femoral artery divides into deep profunda femoris and superficial femoral
- Profunda femoris give off medial and lateral circumflex femoral arteries
- Superficial femoral runs to the apex of femoral triangle and enters the adductor canal and exits the adductor hiatus to form the popliteal artery.
Name the muscles that make up the hamstrings and innervations
Biceps femoris
• Long head from ischial tuberosity, short head from linea aspera
• Inserts head of fibula
• Long head - Tibial part of sciatic nerve
• Short head – Common peroneal
• Main action is flexion at the knee. It also extends the thigh at the hip, and laterally rotates at the hip and knee.
• Semitendinosus – tendon like structure
• Ischial tuberosity
• Medial surface of the tibia
• Tibial part of sciatic nerve
Semimembranosus (Under semimembranosus)
• Ischial tuberosity
• Attaches to medial tibial condyle
• Flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint.
Name the adductor muscles of the thigh
- Gracillis
- Inferior rami+ body of pubis descends vertically down the leg, attaches to medial surface of the tibia - Pes Anserinus
- Adductor longus
- Broad fan structure originates from pubis attaches to linea aspera
- Obturator (L2,3,4)
- Adductor brevis
- Lies in between anterior and posterior divisions of obturator nerve
- Body of pubis + pubic rami and attaches to linea aspera on posterior surface of femur
- Obturator
- Adductor Magnus
- Adductor part originates from inferior rami of the pubis and rami of ischium attaches to linea aspera – Obturator
- Hamstring part originates from ischial tuberosity and attaches to adductor tubercle and medial supracondylar line of femur – Tibial compartment of Sciatic
Name the muscles that make up the quadriceps
Rectus Femoris
• Orgin – AIIS, part of ilium superior to acetabulum Vastus Lateralis
• Greater trochanter and lateral lip of linea aspera Vastus medialis
• Intertrochanteric line and medial lip of the linea aspera
Vastus intermedius
• Anterior and lateral surfaces of femoral shaft
Name the boundaries of the Hunter’s Canal
- Lateral: Vastus Medialis
- Posterior: Adductor longus and adductor magnus
- Anterior: Sartorius
Structures passing through Hunter’s canal
- Superficial femoral artery
- Femoral Vein
- Saphenous nerve
- Nerve to vastus medialis
- Terminal division of the obturator nerve
- Lymphatics
Describe the characteristic features of the medial and lateral menisci
- Medial meniscus
- Elongated C shaped structure (as the tibial surface is larger on the medial side)
- Attached to medial collateral ligament and joint capsule- less mobile – therefore more susceptible to injury as cannot accommodate for abnormal stresses
- Lateral meniscus
- Smaller and more circular
- No attachment to the lateral collateral ligament or joint capsule therefore is more mobile
- Popliteus tendon runs between the joint capsule and the lateral meniscus
What structures are encountered during arthroscopic surgery to the knee – anterior approach?
• Transverse meniscal ligament • Anterior horn of medial meniscus • ACL • Anterior horn of lateral meniscus • Posterior horn of medial meniscus • PCL `
Describe attachments of ACL and PCL
- ACL – attaches to the anterior intercondylar area of the tibia (medial aspect) and runs up and posterior laterally to attach to medial surface of lateral femoral condyle
- PCL – attaches to the posterior intercondylar area (lateral aspect) and runs up and superiomedially to attach to lateral surface of medial femoral condyle
Describe the bursae around the knee joint
- Suprapatellar Bursa: Lies between the inferoanterior surface of the femur and the deep surface of quadriceps
- Prepatellar Bursa: Between Patella and the skin
- Infrapatella bursae: superficial and deep
- Semimembranosus bursa
How are patellar fractures managed?
- Conservative if non displaced/minimally displaced
- Surgical if extensor lag or significant displacement
- ORIF with Tension band wiring
Boundaries of popliteal fossa?
- Superomedial: Semimembranosus
- Superolateral: Biceps femoris
- Inferomedial: Medial head of Gastroc
- Inferolateral: Lateral head of Gastroc
- Floor: Popliteal surface of femur, capsule of knee joint and popliteus
Contents of popliteal fossa?
- Popliteal artery (Deepest) – commences at adductor hiatus
- Popliteal Vein (Small saph vein drains)
- Tibial Nerve
- Common Peroneal Nerve
Blood supply of the knee joint
- Five Genicular branches of popliteal artery – genicular anastomoses
- Descending genicular branch of femoral
- Descending genicular branch of lateral femoral circumflex
- Anterior recurrent branch of anterior tibial artery (Inferolaterally)
Describe course of popliteal artery
• Popliteal artery descends down and gives off genicular branches and exits between gastrocnemius and popliteus
• At lower border of popliteus, popliteal arterial terminates and gives off
o Anterior tibial and Tibioperoneal
• Anterior tibial
o Passes anteriorly between extensor hallucis longus and tibialis anterior close to IO membrane
o Moves inferiorly down the leg can be palpated between two malleoli at the anterior aspect of the ankle lateral to the tendon of EHL
o Becomes dorsalis pedis at distal edge of the retinaculum – DP pulse between 1st and second metatarsals of the foot
• Tibioperoneal
o Posterior tibial – posterior compartment - enters foot with tibial nerve in tarsal tunnel
o Peroneal artery – Lateral compartment- travels posterior to fibula Perforating branches
Name muscles of anterior compartment of lower leg
- Tibialis Anterior
- Extensor Digitorum longus
- Extensor Hallucis longus
- Fibularis tertius
Name origins and insertion of the anterior compartment muscles
- All supplied by deep fibular nerve- DORSIFLEXION AND INVERSION OF FOOT
- Tibialis anterior
- Origin: Lateral surface of tibia attaches to medial cuneiform and base of 1st Metatarsal
- Strongest dorsiflexor of foot
- Extensor Digitorum Longus
- Origin: Lateral condyle of the tibia and the medial surface of the fibula, fibres converge and travel down to the foot where they split into four, each inserting onto a toe
- Extension of lateral four toes, dorsiflexion of the foot
- Extensor hallucis longus
- Originates from the medial surface of the fibular shaft
- Tendon crosses anterior to ankle joint and attaches to the base of distal phalanx of great toe
- Extension of great toe and dorsiflexion of the foot
- Fibularis Tertius
- Originates with EDL on medial surface of the fibula, tendon descends with EDL but diverges and attaches to 5th Metatarsal
- Eversion + Dorsiflexion of the foot
Lateral compartment of leg – PLANTARFLEX AND INVERSION
Fibularis longus
o Origin: superior and lateral surface of fibula and lateral tibial condyle
o Tendon passes posterior to lateral malleolus – medial cuneiform and base of 1st metatarsal
o Superficial fibula (L4-S1)
Fibularis Brevis
o Inferolateral aspect of fibula, travels with longus and passes posterior to lateral malleolus and inserts on to 5th MT
o Superficial fibula (L4-S1)
Posterior Compartment of leg
Gatrocnemius
- Lateral head – lateral femoral condyle
- Medial head – Medial femoral condyle
- Converge together and insert onto calcaneus
Plantaris - Lateral supracondylar line of the femur
- Muscle descends medially between gastroc and soleus
Soleus - Originates from soleal line of the tibia and proximal tibia
Posterior Compartment of leg - deep muscles
Deep Muscles
Popliteus
- Forms base of popliteal fossa
- Originates from lateral condyle of the femur and the posterior horn of lateral meniscus
- Inserts above the origin of soleus muscle
Tibialis Posterior
- Originates from the interosseous membrane between the tibia and fibula, posterior surfaces of the two bones
- Tendon enters the foot posterior to the medial malleolus and attaches to medial tarsal bones
Flexor Digitorum Longus
- Originates from medial surface of the tibia, attaches to plantar surfaces of lateral four digits
Flexor Hallucis Longus
- Originates from posterior surface of the fibula, attaches to the plantar surface of great toe phalanx
What is tarsal tunnel
Borders
o Floor – cancave surface formed by medial aspect of tibia, talus and calcaneus
o Roof – Flexor retinaculum
Contents
o Tom Dick and Very Naughty Harry
