3- clinical anatomy of lower limb

Question 1

what are 3 passive forces that stabilise hip joint?

Answer 1

1. bone architecture = acetabulum is deep & nice fit for head of femur
2. labrum = fibrocartilage rim along margin of acetabulum
3. ligaments = iliofemoral, pubofemoral & ischiofemoral. they twist together getting tighter when extension and twist and get looser in flexion

Question 2

what is the relationship about muscles & ligaments supporting stability of hip joint?

Answer 2

• anteriorly = ligaments most support and less muscle
• posteriorly = more muscles and less support from ligaments

Question 3

what is most supportive ligament of hip?

Answer 3

iliofemoral = it’s y shaped one at front (is why ligaments are more supportive anteriorly)

Question 4

why is it important to be aware of extension of bone into acetabulum?

Answer 4

may cause instability of the joint

Question 5

which type of hip dislocation is more common, why?

Answer 5

posterior hip dislocation more common because more muscle but weaker ligaments
most common example is car crash, knee on steering wheel or dashboard pushed hip out back (more vulnerable to pop out when sitting down)

Question 6

what nerve can be damaged if posterior hip dislocation? why?

Answer 6

sciatic nerve (as nerve roots L4-S3 and leaves pelvis through greater sciatic foramen inferior to piriformis in glute then runs posterior to acetabulum at level of ischium)

Question 7

what is blood supply to hip joint?

Answer 7

profunda femoris (deep femoral) gives off medial and lateral circumflex arteries and then these give off retinacular which go in and supply head

*medial circumflex supplies most as gives off most retinacular arteries

Question 8

what is trendelenburg’s gait?

Answer 8

when superior gluteal nerve affected meaning gluteus medius & minmus muscles don’t work and get unique walk where one leg like higher up than other

Question 9

why is rotation & shortening of fracture in femoral shaft fracture?

Answer 9

because often muscle still attached so muscle contracts and pulls bits of bone around

Question 10

what are weaker ligaments of ankle?

Answer 10

medial ligaments (deltoid) and lateral ligaments are the 2 groups

• medial ligaments are stronger and lateral ligaments weaker (more likely to be injured)

Question 11

what are the medial ligaments of ankle?

Answer 11

= they are collectively referred to as deltoid ligament which is made up of 4:

1. anterior tibiotalar ligament
2. tibionavicular ligament
3. tibiocalcaneal ligament
4. posterior tibiotalar ligament

Question 12

what is maisonneuve fracture?

Answer 12

= separation (rupture) of tibial fibular ligament AND proximal fibular fracture

• often has common fibular nerve damage = foot drop

Question 13

how do you figure out in foot drop whether it’s common fibular or once branches nerve that is damaged?

Answer 13

common fibular branches to deep & superficial fibular

• superficial fibular supplies fibularis brevis & longus which everts foot so if can’t evert foot then superficial fibular damaged
• deep fibular dorsiflexes foot and toes = by tibialis anterior, extensor digitorum longus & hallucis longus, fibularis tertius →if can’t extend toes then deep fibular damaged

*can also test cutaneous innervation by checking innervation of dorsal surface in superficial & deep areas

*if can’t evert foot or extend toes then damaged before branches