Lower Extremity Injuries Flashcards Preview

Pathophysiology - Connective Tissue / Musculoskeletal > Lower Extremity Injuries > Flashcards

Flashcards in Lower Extremity Injuries Deck (69)
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1
Q

What spinal levels give rise to the superior gluteal nerve and what does it innervate? Does it have a sensory component?

A

L4-S1

Innervates gluteus medius, minimus, and tensor fascia lata (TFL)

No sensory component -> cluneal nerves are what gives sensation to the buttocks

2
Q

What is the origin, insertion, innervation and action of TFL?

A

Origin: ASIS
Insertion: Iliotibial tract
Innervation: Superior gluteal nerve (L4-S1)
Action: hip abduction

3
Q

What is the origin, insertion, innervation, and action of gluteus medius and minimus?

A

Origin:
Medius - Iliac crest
Minimus - Ilium
Insertion: Greater trochanter of femur
Innervation: Superior gluteal nerve (L4-S1)
Action: Hip abductor
Internal rotation thru minimus (anterior surface of greater trochanter)

4
Q

How will a patient present as well as compensate for superior gluteal nerve loss?

A

Presents with Trendelenburg gait -> hip contralateral to affected side will drop during walking

Patient compensates by leaning upper body towards affected side so less weight falls.

5
Q

What is the best place to give IM gluteal injections?

A

Superolateral quadrant of buttocks -> avoids most nerve injury

6
Q

What nerve roots does inferior gluteal nerve arise from? What sensory / motor does it give?

A

Again, it’s a gluteal nerve, so no sensory. Since inferior, it is one less than superior:
L5-S2.

Gives motor to gluteus maximus

7
Q

What is the origin, insertion, innervation, and action of gluteus maximus?

A

Origin - Ilium, sacrum and coccyx, as well as sacrotuberous ligamen

Insertion - Gluteal tuberosity / IT band

Innervation - Inferior gluteal nerve (L5-S2)

Action: Extension of hip

8
Q

What nerve is affected in “skinny jeans syndrome” and what nerve roots does it come from? Where will motor or sensation be lost?

A

Lateral femoral cutaneous nerve

L2-L3 nerve roots, from lumbar plexus

Sensation will be lost on anterior and lateral thigh

Nerve has no motor output.

9
Q

What nerve roots does the femoral nerve come from? Where / how does it supply sensation?

A

Comes from L2-L4 of lumbar plexus

Sensation:
Anterior thigh (via anterior cutaneous nerves)
Medial leg (via saphenous nerve)
10
Q

What does the femoral nerve supply motor to?

A

Iliopsoas - hip flexors
Pectineus - flexor and adductor of thigh
Quadriceps - leg extensors
Sartorius - Hip and knee flexor

11
Q

What are the origin, insertion, innervation, and action of the psoas muscles?

A

Origin - Transverse processes of T12-L5
Insertion - Lesser trochanter of the femur (medially)
Innervation - Femoral nerve (really ventral rami of L1-L3)
Action - Hip flexors

12
Q

What are the origin, insertion, innervation, and action of the iliacus?

A

Origin - Ilium, iliac crest, lateral sacrum
Insertion - Lesser trochanter of the femur (medially), joining with fibers of psoas muscle
Innervation - Femoral nerve
Action - Hip flexor

13
Q

What are the four muscles of the quadriceps femoris? Where do they all insert? What innervates them?

A

Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius

All innervated by femoral nerve (L2-L4), inserting on the superior pole of the patella

14
Q

What are the origin and action of the rectus femoris?

A

Origin: Anterior INFERIOR iliac spine (AIIS)
Action: Extension of leg and SOME FLEXION of the thigh (only quad muscle to cross the hip joint)

15
Q

What are the origin and action of the vastus lateralis?

A

Origin: Lateral lip of linea aspera and greater trochanter
Action: Leg extension

16
Q

What are the origin and action of the vastus medialis?

A

Origin: Medial lip of linea aspera and intertrochanteric crest of femur
Action: Leg extension

17
Q

What are the origin and action of the vastus intermedius?

A

Origin: Anterior and lateral proximal femur

Action: leg extension

18
Q

What is the origin, insertion, innervation, and action of the sartorius muscle?

A

Origin: ASIS (only other one other than TFL)
Insertion: pes anserinus (medial tibia)
Innervation: Femoral nerve
Action: Thigh flexion and leg flexion

19
Q

What is the origin, insertion, innervation, and action of the pectineus muscle?

A

Origin: Superior pubic ramus
Insertion: Pectineal line - Proximal femur just inferior to lesser trochanter
Innervation: Femoral nerve
Action: Adduction of thigh, as well as weak flexor

20
Q

What are motor and sensory functions of the obturator nerve? What nerve roots does it arise from?

A

Sensory - medial thigh
Motor - Adductors of thigh, gracilis, obturator externus, and pectineus (along with femoral nerve)

Same as femoral nerve: L2-L4

21
Q

What is the origin, insertion, innervation, and action of the obturator externus?

A

Origin: Obturator foramen / obturator membrane (on the outside. Internus is from inside)
Insertion: Intertrochanteric fossa
Innervation: Obturator nerve (L2-L4)
Action: External rotation of the thigh

22
Q

What are the three adductors for the thigh, what innervates them, and where do they insert? (this is in general)

A
  1. Adductor Longus
  2. Adductor Brevis
  3. Adductor Magnus

Originate from the pubic bone
Insert on linear aspera of femur
Innervation: Obturator nerve

23
Q

What is the origin, insertion, innervation, and action of gracilis?

A

Origin: Pubic symphysis
Insertion: Pes anserinus (superior medial tibia)
Action: Adductor of thigh, some leg flexion
Innervation: Obturator nerve

24
Q

What is the mnemonic for things which insert on the pes anserine bursa and their innervation?

A

remember pes anserine means foot.

Sergeant foot = SGT FOT

Sartorius -> Femoral
Gracilis -> Obturator
semiTendinosus -> Tibial

25
Q

What are the two components of the sciatic nerve and what nerve roots does it come from?

A

Common peroneal (fibular) nerve and tibial nerve

Sciatic nerve comes from L4-S3

26
Q

What sensory and motor does the sciatic nerve supply before splitting?

A

Sensory -> none. It will supply the the entire lateral leg (as opposed to thigh) which is not supplied by the saphenous nerve

Motor - supplies the hamstrings before splitting into common peroneal and tibial nerve

27
Q

What is the origin, insertion, innervation, and action of the semitendinosus?

A

Origin: Ischial tuberosity
Insertion: Pes anserinus (Sgt foot)
Innervation: Tibial division of sciatic nerve
Action: Extends thigh, flexes leg

28
Q

What is the origin, insertion, innervation, and action of the semimembranosus?

A

Origin: Ischial tuberosity
Insertion: Posterior medial tibial condyle
Innervation: Tibial division of sciatic nerve
Action: Extends thigh, flexes leg

29
Q

What is the origin, insertion, innervation, and action of the biceps femoris?

A

Origin: Ischial tuberosity (like all hamstring muscles)
Insertion: Head of the FIBULA
(just remember that membranosus / tendinosus insert on the medial side, so femoris must insert laterally on the fibula)
Innervation: Long head by tibial division of sciatic nerve, short head by common peroneal division
Action: Long head extends thigh, both flex the leg

30
Q

What nerve roots does the tibial nerve come from and what is its course?

A

L4-S3, same as sciatic nerve. Comes from the sciatic nerve, travels thru popliteal fossa, innervates all of the posterior muscles of the leg before finally giving branches to the soles of the feet.

31
Q

What provides sensation to the inferior lateral back of the leg and sole of the feet?

A

Back of the leg, especially laterally / inferiorly -> sural nerve, a branch of the tibial nerve from the popliteal fossa.

Sole of the feet -> branches of the tibial nerve as it continues inferiorly after supplying the gastrocnemius and other plantarflexors

32
Q

What provides sensation to the superior lateral back of leg and dorsum of the feet?

A

Superior lateral leg -> lateral cutaneous nerve of the leg, a branch of the common peroneal nerve.

Dorsum of the feet -> superficial peroneal (branch of the common peroneal nerve)

Between digits 1 and 2 -> deep peroneal nerve (branch of common peroneal)

33
Q

What muscles does the tibial nerve supply?

A
Gastrocnemius
Soleus
Plantaris
Popliteus
Tibialis Posterior
Flexor digitorum longus
Flexor hallicus longus
Flexors of the feet
34
Q

What happens in injury to the tibial nerve?

A

Inability to curl toes (flex) and loss of sensation on sole of feet

Remember “TIP”
Tibial Inverts + Plantarflexes the foot -> lose the ability to show inside of foot and step on the gas, can’t walk on tiptoes.

35
Q

What muscles does the common peroneal nerve supply?

A

Superficial branch: Fibularis longus and brevis

Deep branch: Tibialis anterior, extensor digitorum longus and brevis, extensor hallicus longus and brevis, fibularis tertius

36
Q

What happens if the common peroneal nerve is injured?

A

Loss of tibialis anterior function, as well as loss of sensation on upper lateral leg and dorsum of the foot.

Think PED:
Peroneal Everts + Dorsiflexes
-> loss = FOOT DROP. Foot will be plantarflexed and inverted at rest.

37
Q

What is the cause of a pediatric avulsion?

A

Muscles and tendons are stronger than the bones which have not had their growth plates closed yet -> fractures to growth plate in children / adolescents

38
Q

What is damaged in an avulsion fracture of the iliac crest?

A

Abdominal muscles which attach to it: Transversus abdominis, external abdominal oblique, internal abdominal oblique

39
Q

What is damaged in an avulsion fracture of the ASIS?

A

Sartorius, tensor fascia lata

40
Q

What is damaged in an avulsion fracture of the AIIS?

A

Rectus femoris

41
Q

What is damaged in an avulsion fracture of the ischial tuberosity?

A

Hamstrings

42
Q

What is damaged in an avulsion fracture of the body of the pubis / inferior pubic ramus?

A

Adductors of thigh, and gracilis

43
Q

What is damaged in an avulsion fracture of the greater trochanter?

A

Medial (i.e. gluteus minimus)and lateral (i.e. superior / inferior gemellus, quadratus femoris) rotators of the thigh which insert there

44
Q

What is damaged in an avulsion fracture of the lesser trochanter?

A

Iliopsoas muscle

45
Q

Who classically gets a hamstring injury / how does it happen? What are the signs?

A

Classically happens in HURDLERS, who jump and injury it by stretching it in jumping = full hip flexion and knee extension.

Pain, ecchymosis, weakness of knee flexion

46
Q

What is the most common way to dislocate your hip and why?

A

Posterior dislocation which leaves it adducted and internally rotated

-> typically occurs due to a car accident where the leg hits the dashboard and is driven backwards relative to torso.

47
Q

What two arteries supply blood to the head of the femur and what is the main one which causes AVN if lost?

A
  1. Medial circumflex femoral artery. Branches medially from femoral artery and wraps posteriorly to supply the neck of the femur.
  2. Obturator artery -> weak blood supply. It is a branch of the internal iliac which passes with the obturator nerve thru the obturator foramen.
48
Q

Is it more important to do emergent surgery if someone breaks the center of their femur or the distal femur by the joint?

A

Distal femur by the joint -> if broken to pieces and not fixed properly, patient will have degenerative arthritis for life

49
Q

Where does an ACL run normally? What signs indicate it’s torn?

A

Anterior tibia to lateral femoral condyle

Positive Lachman test (30 degrees) and anterior drawer sign (90 degrees flexion)

50
Q

Where does a PCL run normally? What sign indicates it’s torn?

A

Posterior tibia to medial femoral condyle

Positive posterior drawer sign

51
Q

What is the most common way in which the PCL is injured?

A

Hyperflexion of the knee with a plantarflexed foot (non-contact), or dashboard injury which displaces lower leg backwards (similar to a hip flexion injury).

52
Q

What is the mechanism of MCL injury and what test is done to identify it?

A

Usually occurs in football players who sustain a lateral blow to their planted foot

Identified via abnormal passive abduction -> valgus force with leg fully extended or flexed at 30 degrees causes abnormal medial gapping

53
Q

Where does the LCL travel and what causes injury? What test is done to identify a tear of it?

A

Travels from the lateral femoral condyle to the proximal fibula

Injured by a medial blow to the knee

Identified via abnormal passive adduction (lower leg adducts passively) -> varus force with leg fully extended or flexed at 30 degrees causes abnormal lateral gapping

54
Q

What nerve will be damaged in a fibular neck fracture? What are its nerve roots?

A

Common peroneal nerve (L4-S2) which wraps just around the fibular neck

55
Q

What’s the McMurray test checking for and what does each way mean?

A

Medial / lateral meniscus tear

Pain / popping with lower leg in internal rotation -> lateral meniscus tear

Pain / popping with lower leg in external rotation -> medial meniscus tear

56
Q

What is the unhappy triad and what causes it?

A

Sports injury due to valgus force applied to a planted leg

ACL, MCL, and medial meniscus tear
Medial meniscus tears because it is attached to the MCL, which tears for obvious reasons

57
Q

How many ligaments must be torn for a knee dislocation and what artery / nerve are we most worried about?

A

> 1 ligament must be torn

Worry about:
Artery: decreased / absent popliteal pulse
Nerve: common peroneal nerve

58
Q

If a patient is unable to do a straight leg raise which two tendons could be out? How do you tell which one it is based on X-ray?

A

Either the Quadriceps tendon (attaching to superior pole of the patella) or the patellar tendon (attaching to the tibial tubercle)

Both these tendons are needed for extension carried out by the quads.

On X-ray, the patella will be pulled closer in the direction of the INTACT tendon for obvious reasons.

59
Q

What could the pathology be if the patient can’t do a straight leg raise but the quadriceps tendon and patellar tendon are intact?

A

Could be a patellar fracture (ripped the bone in half)

60
Q

What is Sinding-Larsen-Johansson syndrome?

A

Adolescents who play jumping sports often get chronic pain at the INFERIOR POLE of the patella (requires hard extension of the leg when jumping)

Treat with rest and NSAIDs

61
Q

What condition is essentially the same as Sinding-Larsen-Johansson syndrome but affects the tibial tubercle?

A

Osgood-Schlatter disease -> same cause, in adolescents with jumping. 90% will get better when they get done growing.

62
Q

What condition is common in wrestlers who get repetitive trauma to the knees? Who also gets it and what is it called?

A

Pre-patellar bursitis

Also occurs in people who kneel chronically -> i.e. Housemaid’s knee.

Swelling of the bursa IN FRONT of the kneecap

63
Q

What complication does proximal tibia fracture commonly cause?

A

Compartment syndrome. Difficult to reduce -> bleed into confined fascia space

64
Q

What is the cause of a high ankle sprain and what is disrupted?

A

External rotation injury

Disruption of the syndesmosis that holds the tibia and the fibula together distally (fibula makes lateral malleolus which btw runs further inferior than the medial malleolus)

Syndesmosis composed of two ligaments:

  1. Anterior inferior tibiofibular ligament (AITFL)
  2. Posterior inferior tibiofibular ligament (PITFL)
65
Q

What radiographic finding is indicative of a high ankle sprain?

A

Increased gap between the medial malleolus and the talus bone -> should normally be uniform

66
Q

What are the two most common ligaments injured in low ankle sprain, and how are they injured?

A

ATFL - anterior talofibular ligament -> falling on plantarflexed and inverted foot

CFL - calcaneofibular fibular ligament -> falling on dorsiflexed and inverted foot

67
Q

What test is used to differentiate between an ATFL and CFL low ankle sprain?

A

Anterior drawer test of the foot.

If you can pull the foot anteriorly when it’s in plantarflexion -> ATFL injury

If you can pull the foot anteriorly when it’s in dorsiflexion -> CFL injury

68
Q

How does an Achilles tendon rupture tend to happen and where does it occur?

A

Tends to happen in sudden forced plantarflexion -> trying to explode off the ground during a box jump

Occurs in the watershed area 4-6 cm proximal to your calcaneus (where the blood supply is poor)

69
Q

What test is used to assess for an Achilles tendon tear?

A

Thompsons test -> Squeeze the gastrocnemius / soleus by squeezing calf. If the foot does not move (plantarflex) at all, then you have an Achilles tendon tear.