L7.2 Hips and Thighs

Question 1

Torsions of LL embryogenesis

Answer 1

• Flexion of LL during embryogenesis (becomes region of knee)
• Then undergoes torsion (pronation & Internal rotation)

Question 2

Differences between the UL & LL

Answer 2

• UL undergoes ex rotation & supination; LL internal rotation & pronation
• Pec girdle not complete ring; Pelvic girdle complete ring
• Valgus UL; Valrus LL
• Opposable thumb; non-opposable big toe
• Weight of body not directly on joints of LL
• Longitudinal arch of foot: body weight picked up by arch

Question 3

Pelvic girdle

Answer 3

• 2 bones on each side - os coxa
  
  • Ilium (biggest)
    
    • Fuse late in life
    • Crest, fossa, ASIS & AIIS
  • Ischium
    
    • Strong body → meets acetubulum
    • Ramus → encloses obturator foramen
  • Pubis
    
    • Sup/Inf Ramus → encloses obturator foramen as well
    • Body → meets the other body (Pubic symphysis)

Question 4

Pelvic girdle (lat view)

Answer 4

• PSIS/PIIS → where ilium meets sacrum
• Greater Sciatic notch + Sacral ligament → becomes foramen
• Ligament from sacrum to ischial spine
• Lesser sciatic notch + sacrotuberous ligament → foramen
• Ligament from sacrum to ischial tuberosity
• Crest of pubis (spine from acetubulum → the pointy bit

Question 5

Fracture of the pelvic girdle?

Answer 5

• From direct trauma
• Breaking pelvis on one side → breaks the other
• Most common fracture → pubic symphasis → rami also broken

Question 6

Sacrum

Answer 6

• 5 fused vertebera → forms transverse ridges
• Linea terminalis → opening of pelvis medially (when sacrum meets with pelvic rim)
• Promontory (ANT) → bony projection at S1 → tilts sacrum in pelvis
• Ala (LAT) → ear shaped regions (auricular surfaces → where sacrum meets iliac bone)
• TP fuse → lat sacral crest
• SP fuse → med sacral crests
• ArtP fuse → Intermediate sacral crests
• ANT sacral foraminae → carries ANT rami
• POS sacral foraminae → carries POS rami

Question 7

Coccyx

Answer 7

• 4 vertebra fuse
• Have bony projections - coccyxseal cornu

Question 8

Femur

Answer 8

• Head is 2/3 of sphere
• Neck - long (moves shaft away from head) → allows legs to move more efficiently
• Greater/lesser trochanters→ more prominent than humerus
• Intertrochanteric line (ANT); Intertrochanteric crest (POS)
• Linear aspera → has Lat & Med lip
• Shaft → Med angulation (valrus)
• Lat & med epicondyle
  
  • Adductor tubercle on the medial side
• Condyles at the end (intercondylar fossa in the middle)

Question 9

What is the angle of inclination?

Answer 9

• Angle of inclination (determined by placing condyles flat on the table)
• Males > females (wider hips) (~125o in adults)
• Newborns > adults (~160o)
  
  • Congenital dislocation: adductor muscles pull shaft medially (bones not fully fused)
  • Coxa Vera (110o): Epiphyses of femur → sits at edge of acetabulum → may caused slipped capital femoral epiphysis​

Question 10

Fractures of femur

Answer 10

• Neck of femur (more common in females - ↑osteoporosis)
• Sign of fracture: thigh ex rotated, fracture limb looks shorter
• May cause: avascular necrosis
  
  • Particularly in retinacular branches

Question 11

Fascia lata

Answer 11

• Deep fascia surrounding thighs : Fascia lata
  
  • Thickens lat to form iliotibial band (ITB) - from iliac crest → lat knee

Question 12

ANT Hip muscles

Answer 12

• Iliopsoas: Hip & thigh flexors; trunk flexor when pelvis flexed (sit-ups) → may compress lumbar vert causing ANT shear at L5/S1 (psoas maj + iliacus)
  
  • Psoas maj: T12-L4 → iliac crest → lesser trochanter
  • Iliacus: fossa of ilium → joins with psaoas maj → lesser trochanter
• Psoas min:
  
  • Only in 50% of population
• Pectoneus: btw ANT & POS compartment → NS from both compartments
  
  • Origin: Ramus → shaft of femur (INF to lesser trochanter)
  • Flexion & Med rotation & adduction
• Sartorius: tailor muscle (ex rotation)
  
  • ASIS → (from lat to med) med prox end of tibia
  • Flexes thigh & leg at knee joint

Question 13

ANT Thigh muscles

Answer 13

• Quadriceps femoris: 4 muscles join together with patellar ligament → base of patella tuberosity
• Rectus Femoris: origin: AIIS
  
  • 2 joint muscle (helps with hip flexion as well)
• Vastus (origin positions relative to linear aspera)
  
  • Medialis: Intertrochanteric line
  • Intermedius: Shaft of Femur
  • Lateralis: Greater Trochanter
• Quad muscles causes tendency of LAT patellar dislocation
• Prevention of dislocation:
  
  • V.M fibres
  • LAT epicondyle lip
  • Retinacular fibres

Question 14

Medial Thigh muscles

Answer 14

• Origin: Body of pubis → shaft of humerus (except for Gracilis)
• Adductor Longus
• Adductor Brevis
• Adductor Magnus (2 compartments: ANT & POS)
  
  • Origin: body of pubis & ischial tuberosity (same as hamstrings) → adductor tubercle (distal Femur)
  • NS from ANT & POS
• Gracilis → insertsL Med, sup tibia
  
  • Assists in adduction (pulls knee joint) & internal rotation of tibia
• Obturator externus: origin: Obturator foramen

Question 15

LAT Thigh muscles (SUP)

Answer 15

• Origin: Gluteal surfaces on ilium → Lat of greater trochanter
• Gluteus maximus (recruited ONLY in power extensions)
• Gluteus medius
• Gluteus minimus
  
  • Both med and min helps maintain position of pelvis in locomotion
    
    • Stops LAT tilt of pelvis
  • Gluteal muscles are large → good site of IM injections (inject along the sup iliac crest → no BS/NS)
• Tensor fascia lata: Iliac crest, ASIS → (along ITB) Lat tibia
  
  • Knee extensor & lat support to knee joint
  • Non-fatigue structure

Question 16

LAT Thigh muscles (deep)

Answer 16

• Lat rotators → fixators of hip joint; all insert to the greater trochanter (through sciatic notch)
  
  • Piriformis: Sacrum
    
    • A landmark region: sciatic nerve, INF gluteal A&N below, superior gluteal A&N above
  • Sup/Inf gemellus: Ischial spine
  • Obturator intermus: Internal foramen
  • Quadratum fermoris: Ischial tuberosity

Question 17

POS Thigh muscles

Answer 17

• Hamstrings: origin ischial tuberosity
  
  • Semitenionsus (Sup)
  • Semimembranosus (deep)
    
    • Both inserts into the medial epicondyle of the tibia
  • Biceps femoris: 2 heads
    
    • Long head (innervated by tibial sciatic N): originate from ishicial tuberosity
    • Short head (innervated by common fibular N): originate from shaft of femur (lat supracondylar ridge)
      
      • Both joins and inserts into head of fibular
• ‘Pes anserinus’ or ‘foot of the goose’
  
  • Semitendinosus + gracilis + sartorius