LE arthrology LOs

Question 1

sacroiliac joint

Answer 1

• planar joint: surfaces glide 4 mm
  
  • nutation: anterior rotation of sacrum, inferoposterior glide
  • counter nutation: posterior rotation of sacrum, anterosuperior glide

Question 2

hip/femoroacetabular joint

Answer 2

• synovial, ball and socket
  
  • convex femoral head
  • concave acetabulum
• motions
  
  • flexion: spin with inferior and posterior glide
  • extension: spine with anterior and superior glide
  • ER: anterior glide
  • IR: posterior glide
  • adduction: superior glide
  • abduction: inferior glide

Question 3

patellofemoral

Answer 3

• planar joint: for flexion and extension
  
  • patellar slides within trochlear groove of femur
• motions
  
  • flexion: inferior glide
  • extension: superior glide
  • some medial and lateral gliding

Question 4

proximal (superior) tibiofibular joint

Answer 4

• planar
• motions
  
  • extension: posterior glide
  • flexion: anterior glide

Question 5

tibiofemoral joint

Answer 5

• hinge, bi-condylar
• larger medial femoral condyle
  
  • tibia ER with full extension – pivots of tibia on femur laterally from 30 to 0
• concave tibia (menisci)

Question 6

dynamic/muscular stability of SIJ

Answer 6

SIJ

• transversus abdominis, latissimus dorsi, gluteus maximus

Question 7

labrum

Answer 7

• closed off by transverse acetabular ligament
• may provide stability

Question 8

femoral osseous angles

Answer 8

angle of inclincation

angle of torsion

Question 9

angle of inclination

Answer 9

• implications on joint reaction forces and muscle demand
• normal angle 125 degrees
• coxa varus: 115 degrees
  
  • reduced muscles forces needed
  • increases force across femoral neck
  • leads to genu valgum at knee
• coxa valga: 140 degrees
  
  • increased muscle F
  • less F on femoral neck
  • leads to genu varum at knee

Question 10

angle of torsio

Answer 10

• torsion in femoral shaft relative to head and neck
• 8-15 degrees is normal
  
  • angle between axis of femoral condyles and axis of femoral head
• excessive anteversion – 35 degrees
  
  • toe in
• retroversion – 5 degrees
  
  • toe out

Question 11

labral tears

Answer 11

• very common
• 70% of asymptomatic individuals have labral pathologies

Question 12

meniscal tears

Answer 12

• several types, can do repairs
  
  • for traumatic lesion in vascular zone

Question 13

patellar instability

Answer 13

• anatomic facotrs
  
  • MPFL or retinacular deficiency
  • shallow trochlear groove
  • flat patella/trochlear dysplasia
  • patella alta (high patella)

Question 14

tibiofibular dislocation

Answer 14

• ligament repair
  
  • implications in recovery

Question 15

distal (inferior) tibiofibular joint

Answer 15

• planar, syndesmosis
• mainly supported by AITFL (anterior inferior tibiofibular ligament) and interosseous membrane

Question 16

talocrural (ankle mortise) joint

Answer 16

• hinge joint
  
  • convex talus
  • concave distal tibia
• open chain motion
  
  • dorsiflexion: talus glides posterior in mortise, syndesmosis gaps, fibula glides psoterior
  • plantarflexion: talus glides anterior in mortise, syndesmosis closes, fibula glides anterior
• closed chain motion - maybe
  
  • dorsiflexion: tib/fib glides anterior
  • plantarflexion: tib/fib glides posterior

Question 17

subtalar (talonavicular and talocalcaneal)

Answer 17

• anterior
  
  • convex talus on concave calcaneus (mid and ant)
• posterior
  
  • concave talus on convex calcaneus (post)
• 3 planes of motion: inv/ev, pf/df, abd/add

Question 18

transverse tarsal (rearfoot to midfoot)

Answer 18

• talonavicular
  
  • convex talus on concave navicular bone
• calcaneocuboid
  
  • saddle/sellar
• movements coupled with subtalar joint
  
  • df/pf
  • add/abd

Question 19

intertarsal joints

Answer 19

• planar
• provide stability
• transfer forces

Question 20

tarsometatarsal joint

Answer 20

• planar
• provide stability

Question 21

metatarsophalangeal

Answer 21

• condyloid
  
  • convex metatarsal head to concave base of proximal phalanges
• supported by collateral and plantar ligaments

Question 22

interphalangeal joints

Answer 22

• hinge joints
• flexion and extension
• supported by collateral ligaments

Question 23

high ankle sprain

Answer 23

• injury to ATFL and/or syndesmosis (1-11% of ankle sprains)
• hyperdorsiflexion – snowboarding
• eversion, rotation, df – collision sports

Question 24

spring ligament rupture

Answer 24

• acute trauma, diabetes
• loss of medial longitudinal arch
• inferior migration of talus