Anatomy of Lower Limbs

Gross Anatomy

 Bones and how to side them

Pelvis:

To side pelvis, look at the ischial tuberosities, obturator foramen and acetabular notch

Side the pelvis bone Hip joint Parts of pelvis labelled
Side the pelvis bone Parts of pelvis bone
Pelvis bone inferior, middle and superior gluteal line Parts of pelvis bone, hip bone

Femur:

  • Posterior: Linea aspera, intertrochanteric crest
  • Medial condyle larger and downwards, adductor tubercle on medial side
Side the femur Parts of femur

NB: Blood supply to head of femur – Nutrient artery, artery in ligamentum teres, medial and lateral circumflex arteries

Patella:

  • Ant: rough surface
  • Post: smooth, lateral facet larger
Side the patella anterior and posterior Parts of the patella

Tibia:

  • Anteriorly is tibial tuberosity
  • Medial malleolus
  • Anterior border sharpest
Side tibia and fibula Parts of the tibia Parts of the fibula

Fibula:

  • Lateral malleolus
  • Head has styloid process and articular facet on lateral head

Bones of foot:

Bones of foot, tarsals, talus, calcaneus Side the foot bones

Clinicals: club foot, flat foot, hammer toe, bunion

Talus:

  • On lateral side is a bulge as seen from above
  • Medial surface has comma shaped articular facet
  • Planter surface has deep groove
  • Anterior surface has head

Cuboid:

  • Proximally concave
  • Superiorly broad and rough
  • Inferiorly oblique groove and ridge behind the groove
  • Laterally notch
  • Medially oval facet and broad

Calcaneus:

  • Posterior part rough and large
  • Lateral surface straight, medial surface concave

 

Muscle attachment on bones

Image result for muscle attachments on pelvis Insertion and origin of muscles on Pelvis bone
Image result for muscle attachments on femur Insertion and origin of muscles on femur bone
Image result for muscle attachments on femur
Image result for muscle attachments on tibia and fibula Insertion and origin of muscles on tibia and fibula Anterior
Image result for muscle attachments on tibia Insertion and origin of muscles on tibia and fibula Posterior

Arteries

Arteries of lower limb Flowchart showing each artery from abdominal aorta Common iliac artery, internal iliac artery, external iliac artery, profunda femoris, popliteal artery, anterior tibial artery, posterior tibial artery, superficial femoral artery

(I) Anastomosis

Trochanteric anastomosis – SLIM

  • Superior gluteal a.
  • Lateral circumflex
  • Inferior gluteal
  • Medial circumflex

Cruciate anastomosis – LIMP

  • Lateral circumflex
  • Inferior gluteal
  • Medial circumflex
  • 1st perforator

Longitudinal anastomosis – perforators

Longitudinal anastomosis, femoral artery, perforating arteries

(II) Femoral artery – anterior thigh

  • From external iliac artery
  • Between ASIS and pubic symphysis
  • Posterior to inguinal ligament
  • Anterior to psoas major muscle

5 branches – Superficial circumflex iliac, superficial epigastric, superficial external pudendal, deep external pudendal and profunda femoris – lateral and medial circumflex and 1-4 perforators

  • Becomes superficial femoral artery
  • Descends through femoral triangle and adductor canal (in here give descending genicular artery)
  • Through adductor magnus hiatus – becomes popliteal artery

(III) Popliteal artery

  • Through adductor hiatus
  • Descends popliteal fossa
  • Between femoral condyles
  • Superficial to popliteus muscle
  • At lower border of popliteus muscle branches into anterior and posterior tibial arteries
  • Other genicular branches: (supply knee joint)
Knee anastomoses, genicular artery

Clinicals – muscles compress artery

(IV) Anterior tibial artery – anterior leg and lateral leg

  • Origin from lower border of popliteus muscle
  • Passes anteriorly by piercing upper end of interosseous membrane
  • Descends between tibialis anterior and extensor digitorum longus
  • Below inferior extensor retinaculum
  • Forms dorsal pedis artery – which forms deep planter artery

(V) Posterior tibial artery – posterior leg

  • Gives off a peroneal artery
  • Runs in posterior compartment of leg between deep and superficial muscles
  • Enters tarsal tunnel behind medial malleolus
  • Divides into medial and lateral planter arteries

(VI) Obturator artery – medial thigh

 

Veins

Veins of lower limbs Flow chart of veins of lower limb Inferior vena cava, external iliac vein, internal iliac vein, femoral vein, great saphenous vein, small saphenous vein, popliteal vein anterior tibial venous comitantes, posterior tibial venous comitantes, dorsal pedis veins

(I) Great saphenous vein

  • Drains dorsal vein of big toe and dorsal venous arch of foot
  • Infront of medial malleolus
  • runs up medial side of leg
  • Courses anteriorly
  • Pierce cribriform fascia at saphenous opening – joins femoral vein in femoral triangle

(II) Small saphenous vein

  • Drains dorsal vein of small toe and dorsal venous arch of foot
  • lateral aspect of foot behind lateral malleolus
  • Runs up posterior aspect of leg
  • Pierces deep fascia between 2 gastrocnemius
  • Drain into popliteal vein

Clinicals: 

  1. Varicose veins – incompetent valves of superficial veins
  2. Grafts – Coronary bypass
  3. Venous cutdown – infuse fluid in dehydrated children at medial malleolus

 

 

Nerves

Nerves of lower limb Flow chart of nerves of lower limb sciatic nerve, tibial nerve, sural nerve, common peroneal nerve planter nerve, deep peroneal nerve, superficial peroneal nerve
Femoral nerve pathway flowchart Obturator nerve pathway, flowchart Saphenous nerve Femoral nerve distribution Saphenous nerve distribution Obturator nerve distribution

Cutaneous Innervation:

Cutaneous nerve distribution anterior and posterior lower limbs planter cutaneous innervation Colour coded lower limbs innervation labelled

Dermatomes:

Dermatomes of lower limb L1 to S3

(I) Sciatic nerve: L4-S3 – posterior thigh

Course:

  • Passes between imaginary line between PSIS to ischial tuberosity to gluteal tuberosity
  • Through infrapiriform compartment, greater sciatic foramen
  • Deep to gluteus maximus muscle
  • Descends posterior thigh
  • Superficial to adductor magnus
  • Deep to biceps femoris
  • At apex of popliteal fossa divides into tibial nerve and common peroneal nerve

Supplies – posterior thigh

Blood supply – inferior gluteal artery, perforators of profunda femoris

Clinical:

  • Piriformis foramen syndrome
  • Injury by wound/femur dislocation – muscles below knee paralyzed
  • Foot drop – peroneal nerve
  • Sciatic hernia – intestines through GSF

(II) Tibial nerve (accompanies posterior tibial artery) – posterior leg

  • Contributes to sural nerve
  • Runs in posterior compartment of leg between deep and superficial muscles
  • Enters tarsal tunnel behind medial malleolus
  • Divides into medial and lateral planter nerves

(III) Common peroneal nerve (damaged – foot drop, called policeman’s nerve)

  • Descends obliquely on lateral side of popliteal fossa (along medial margin of biceps femoris)
  • Winds around head of fibula
  • Deep to peroneus longus – divides into deep peroneal nerve and superficial peroneal nerve

(IV) Deep peroneal nerve – anterior leg

  • Runs on anterior surface of interosseous membrane with anterior tibial artery
  • At ankle joint, goes through extensor retinaculum, divides into medial and lateral terminal branches

(V) Superficial peroneal nerve – lateral leg

  • Lateral compartment of leg
  • Superficial to peroneus brevis
  • Pierces deep fascia to become cutaneous
  • Divides to form medial and intermediate dorsal cutaneous nerve

(VI) Sural nerve

  • Between medial and lateral gastrocnemius muscles, pierces fascia
  • Descends with small saphenous vein
  • Behind lateral malleolus
  • Runs in lateral foot

(VII) Femoral nerve: L2-L4 – anterior thigh

  • From lumbar plexus
  • through psoas major muscle
  • Behind inguinal ligament
  • Through femoral triangle outside sheath
  • Splits into anterior and posterior divisions
  • Terminal branch – saphenous nerve

(VIII) Saphenous nerve

  • Descends through adductor canal with femoral artery and vein
  • Pierces fascia, descends with great saphenous vein
  • Goes through flexor retinaculum
  • Runs in medial foot

(IX) Obturator nerve – medial thigh

 

Joints

(I) Hip joint

Classification: multiaxial ball and socket

Articular surfaces: head of femur and acetabulum notch

Stability factors:

  1. Static: Joint capsule, labrum, depth of acetabulum, ligaments (iliofemoral, pubofemoral and ischiofemoral)
  2. Dynamic: gluteus medius, gluteus minimus, iliopsoas and piriformis

Movements: flex, extend, adduct, abduct, medial rotation, lateral rotation

Blood supply: trochanteric anastomosis and nutrient artery

Nerve supply: femoral, obturator, sciatic and superior gluteal

Clinicals: hip joint dislocations, psoas bursa and femoral fractures

(II) Knee joint – largest joint, lined with hyaline cartilage

Classification: synovial modified hinge joint (condylar and sellar (between femur and patella))

Articular surfaces: patella and condyles of femur and tibia

Stability factors:

  1. Static:
  • Joint capsule
  • Pateller retinaculum (extensions of aponeurosis of vasti medialis and lateralis on each side of patella)
  • Intercondylar eminence
  • Pateller ligament (to tibial tuberosity)
  • Anterior and posterior cruciate ligaments
  • Tibial and fibular collateral (resist valgus instability)
  • Bursa – semimembranosus, suprapateller, popliteal

2. Dynamic: iliotibial tract, semimembranosus and semitendinosus muscle

Movements: flex, extend, medial and lateral rotation

Blood supply: genicular anastomosis and descending genicular artery

Nerve supply: femoral, obturator, tibial and common peroneal

Clinicals:

  • Ligament tears
  • Housemaids bursities – prepateller
  • Clergymans bursities – infrapateller
  • Unhappy triad – medial collateral, medial menisci and anterior crutiate damaged
  • Pateller dislocation – laterally
  • Q angle:
Image result for q angles of the knee
Image result for q angles of the knee

Atypical Q angles

Image result for coxa vara, valgus atypical Q angles

NB: Menisci – fibrocartilage structure. Acts as shock absorber, load transmission, proprioception, produce synovial fluid, protect articular cartilage

Meniscus Tears - OrthoInfo - AAOS patella

NB: Tibia and fibula have a syndesmosis joint and therefore are immovable and are joint by connective tissue. Even radius and ulna

(III) Ankle joint

Classification: synovial hinge joint

Articular surfaces: tibia, fibula and trochlea of talus

Stability factors:

  1.  Static: deltoid ligament, tibiofibular transverse ligament, anterior and posterior talofibular ligament, calcaneofibular ligament
  2. Dynamic: tendons of anterior and posterior leg muscles

Movements: dorsiflexion and planterflexion

Blood supply: malleolar branches of anterior and posterior tibial arteries and peroneal artery

Nerve supply: tibial and deep peroneal

Clinicals:

  • Ankle sprains – lateral ligament weaker so inversion
  • Potts fracture – eversion, breaks lateral malleolus

 

Others

  1. Walking phase:
Image result for walking phase

2. Venous return in lower limbs: Valves, muscular pumps, venae comitans

Image result for venae comitantes

3. Compartment syndrome:

Image result for compartment syndrome the 5 p

4. Extents of gluteal region:

Extents of gluteal region iliac crest, intergluteal cleft, gluteal sulcus

5. Sacrospinous ligament and sacrotuberous ligament form:

(I) Greater sciatic foramen – which piriformis muscle divides into:

  • Suprapiriformic – superior gluteal A,V,N
  • Infrapiriformic – inferior gluteal A,V,N, pudendal nerve and sciatic nerve

(II) Lesser sciatic foramen – Pudendal nerve, nerve and tendon of obturator internus

Greater sciatic foramen Lesser sciatic foramen Sacrospinous ligament Sacrotuberous ligament

6. Popliteous muscle – Tibia fixed, rotates femur laterally. Femur fixed, rotated tibia medially

7. Fascia lata:

Attachments:

  • Superiorly – ASIS, sacrum, coccyx, iliac crest
  • Inferiorly – Bones around knee

Modifications: Iliotibial tract, saphenous opening, cribriform fascia, intermuscular septa

Functions:

  • Muscle attachments
  • Compartmentalize
  • Enclose thigh muscles – less energy used

Clinicals: Fascia lata grafts, compartment syndrome, muscular hernia if fascia cut

8. Saphenous opening – covered by cribriform fascia

Structures passing through: small saphenous vein, superficial epigastric artery, superficial external pudendal

Formed by: Cribriform fascia (roof) and falciform margin

9. Inguinal lymph nodes

Inguinal lymph nodes drainage

10. Iliotibial tract: from iliac crest to lateral patella and lateral condyles

Function: muscle attachment, stabilize lateral knee, maintain hyperextended knee position

Clinical: iliotibial band syndrome – lateral knee pain

11. Angle of declination

Angle of declination femur coxa vara, coxa valgus
Image result for coxa vara

12. Leg compartments 

Fascial compartments of leg - Wikipedia anterior, posterior, lateral
Illustration of the compartments of the lower leg, as well as the ...

13. Triceps surae – gastrocnemius and soleus muscle. Blood supply- sinusoidal

Tendon achilles : blood supply – water shed

14. Pes anserinus – conjoined tendons of sartorius, gracilis and semimembranosus insert on upper medial tibia

15. Tendons from medial to lateral going through the extensor retinaculum:

  • Tom – tibialis anterior
  • Has – Extensor hallucis longus
  • A – Anterior tibial artery
  • Very – vein
  • Nice – deep peroneal nerve
  • Dog – extensor digitorum longus
  • Pet – peroneus tertius

16. Tarsal tunnel contents from medial to lateral

  • Tom – tibialis posterior
  • Dug – flexor digitorum longus
  • A – posterior tibial artery
  • Very – vein
  • Narrow – tibial nerve
  • Hole – flexor hallucis longus

Clinical: tarsal tunnel syndrome – compressed tibial nerve

17. Popliteal fossa:

Boundaries:

The Popliteal Fossa - Borders - Contents - TeachMeAnatomy gastrocnemius, semimembranous, bicep femoris, plantaris
  • Roof – skin and fascia
  • Floor – knee joint capsule, popliteus muscle

Contents:

The Popliteal Fossa - Borders - Contents - TeachMeAnatomy popliteal artery, tibial nerve, common fibular nerve, popliteal vein

Clinical: Baker’s cyst (semimembranous bursa)

18. Femoral triangle:

Boundaries:

Boundaries of femoral triangle, medial base apex lateral
  • Roof – skin and fascia
  • Floor – iliopsoas, adductor longus and pectineus

Contents:

  • Femoral ring and sheath
  • Femoral artery, genitofemoral nerve and  femoral vein (in the sheath)
  • Femoral nerve
  • Inguinal lymph nodes
Contents of femoral triangle NAVEL

Clinicals: femoral hernia, enlarged lymph nodes

19. Femoral ring:

Image result for femoral ring contents and boundaries

Formation:

  • Anteriorly – Fascia transversalis
  • Posteriorly – Fascia iliacus

Clinical: femoral hernia

20. Adductor canal

Boundaries:

Image result for adductor canal boundaries

Contents:

  • Femoral artery and vein
  • Descending genicular artery
  • Nerve to vastus medialis
  • Saphenous nerve

Clinical: Adductor canal compression syndrome (hypertrophy of muscles)

These are summarized notes from various sources, mainly TeachMeAnatomy and Wikipedia