Session 8 - notes and quotes Flashcards Preview

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Flashcards in Session 8 - notes and quotes Deck (54)
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1
Q

What is the iliotibial tract?

A

a fibrous thickening of the fascia lata that extends from the iliac crest down the lateral part of the thigh to the lateral condyle of the tibia and that provides stability to the knee and assists with flexion and extension of the knee

2
Q

What is enclosed within the iliotibial tract?

A

Gluteus maximus

3
Q

What are the nerve roots of the sciatic nerve?

A

L4-S3

4
Q

What are the main divisions of the sciatic nerve? Where do they arise?

A

Common fibular and tibial nerves, arise in the popliteal fossa

5
Q

What are the motor funcitons of the sciatic nerve?

A

It supplies all of the posterior compartment of the thigh and part of adductor magnus directly and all leg and foot muscles (via divisions)

6
Q

What are the sensory roles of the sciatic nerve?

A

Skin of most of the leg and foot, except for medial aspect of leg.

7
Q

What is the course of the sciatic nerve?

A

1) Enters gluteal region via great sciatic foramen inferior to piriformis.
2) Moves mid way between the posterior superior iliac spine and the ischial tuberosity
3) Passes between greater trochanter and ischial tuberosity
4) Descend posterior the deep to biceps femoris; bifurcates into tibial and common fibular nerve at apex of popliteal fossa

8
Q

What is the surface anatomy of the sciatic nerve?

A
  • Enters lower limb in lower region

- Passes between greater trocanter and ischial tuberosity, the sciatic nerve will be in the middle

9
Q

How can the sciatic nerve be injured?

A

Piriformis syndrome (causing sciatica)
Intragluteal injections
Complete and incomplete section of the sciatic nerve

10
Q

What is piriformis syndrome,and what is it caused by?

A

Compression of sciatic nerve via pirifrormis, individuals involved in sports requiring excessive use of gluteal muscles (rock climbing and cyclists).

11
Q

What are the symptoms of piriformis syndrome?

A

Gluteal pain and pain relieved by walking with foot pointing outward (reduces stretch)

12
Q

What happens in complete section of sciatic nerve?

A

Extension of hip impaired, as is flexion of leg. Loss of all leg, ankle and foot motor function.

13
Q

What happens in incomplete section of sciatic nerve?

A

Result of stab wound, often also involves inferior gluteal nerve and/or posterior femoral cutaneous nerve

14
Q

What is the safe region and side of danger for intragluteal injections

A

Lateral is safer, medial is dangerous (sciatic nerve lies deep to this area)

15
Q

Why is the gluteal region used for intramuscular injections?

A

Muscles thick and large, lots of volume for absorption.

16
Q

Where would a intragluteal injection be given?

A

Upper lateral quadrant between ASIS and tubercle of illiac crest, as it is superior to sciatic nerve

17
Q

What are the complication of an IG injection gone wrong?

A

Nerve injury, haematoma and abcess formation

18
Q

What is a prolapse of intervertebral discs?

A

Nucleus pulposus can burst through tear in annulus fibrosis and into the intervertabral foramen, impinging on neurological structures and causing pain

19
Q

How is a prolapsed disc caused?

A

Tension within disk maintained maintained by absorption of fluid. If mechanism fails then tension falls and annulus fibrosis subjected to increased stress.

20
Q

Name three abnormal curvatures of the spine

A

Kyphosis
Lorosis
Scoliosis

21
Q

What is kyphosis?

A

Exaggeration of the posterior thoracic curvature (hunchback). Abnormality can result from erosion of the anterior part of one or more vertebrae and its progression leads to vertebral collapse and overall loss of height.

22
Q

What is lordosis?

A

Exaggeration of the anterior lumbar curvature, may be associated with weakened trunk (anterolateral abdominal wall) musculature.

23
Q

What is scoliosis?

A

Lateral deviation of verterbral column, asymmetric weakness of the intrinsic back muscles, failure of half a vertebra to develop and a difference in the length of the lower limbs cause scoliosis.

24
Q

When is lordosis normal?

A

During pregnancy, to compensate for additional weight of foetus

25
Q

What is a sciatica?

A

Pain in lower back and hip radiating down the back of thigh into the leg, caused by herniated lumbar IV disc that compresses L5 or S1.

26
Q

Why is sciatica so common?

A

Foramina in lumbar region decrease in size, nerves increase in size

27
Q

What causes pain in sciatica?

A

Movements which stretch sciatic nerve

28
Q

What is cervical spondylosis?

A

As you age, IV discs become dehydrated shrinking and collapse. Verterbral joints experience more pressure so they undergo articular cartilage degeneration. Osteoarthritis. Bony spurs also form, narrowing space for nerves to pass through.

29
Q

What is the route of the femoral nerve?

A

In the substance of the psoas muscle and enters the thigh deep to the inguinal ligament. The psoas muscle lies anterior to the sacro-iliac joint. The nerve passes underneath the inguinal ligament which stretches between the pubic tubercle on the superior pubic ramus and the anterior superior iliac spine.

30
Q

What are the nerve roots of the femoral nerve?

A

L2- L4

31
Q

How would you test flexion of the hip

A

Ask the patient to lie on their back and acutely flex the hip on the abdomen to flatten the lumbar spine.

32
Q

How would you test knee extension?

A

Ask the patient to sit on a chair and extend the knee against resistance.

33
Q

Describe the sensory innervation of the thigh

A

The lateral side of the thigh is supplied by the lateral (femoral) cutaneous nerve of the thigh from the lumbar plexus; the front and intermediate aspects of the thigh are innervated by the anterior and medial cutaneous nerves which are branches of the femoral nerve.

34
Q

Name two nerves which pass close to sacroilliac joint

A

Obturator nerve and femoral nerve

35
Q

How would you examine the integrity of the obturator nerve?

A

Adduction – the adductors of the hip (adductor longus, brevis, magnus, gracilis, pectineus and obturator externus) are all supplied by the obturator nerve.

36
Q

If the femoral nerve was divided why would there be sensory loss in part of the foot and state where?

A

A sensory branch of the femoral nerve called the saphenous nerve (running alongside the great saphenous vein) innervates the medial aspect of the foot.

37
Q

What is the blood supply to the hip?

A

Medial and lateral circumflex femoral arteries

38
Q

Why are hip fracture particularly common in older women?

A

Due to osteoporosis

39
Q

What is often torn when femoral neck fractured or dislocated?

A

Retinacular arteries for medial circumflex artery may be ruptured, causing avascular necrosis of femoral head

40
Q

After fracture, what is often only blood supply to femoral head?

A

Artery to the ligament of the femoral head, which is inadequate on its own.

41
Q

What is an intracapsular fracture, and what is an extracapsular fracture

A

Intracapsular - femoral neck fracture

Extracapsular - intertrochanteric fracture

42
Q

What are the main clinical features of intracapsular fracture?

A

Part lateral rotation and leg shortening
Elevation of greater trochanter
Avascular necrosis of femoral head

43
Q

What prevents excessive lateral rotation in an intracapsular hip fracture?

A

Attachment of the distal fragment to the capsule.

44
Q

Give clinical features of extracapsular (intertrochanteric) fractures

A

Blood supply not interfered with, so no avascular necrosis
Greater area of contact between articular surface
Leg shortening and full lateral rotation

45
Q

Which type of hip fracture is more common in elderly patients

A

Extracapsular (intertrochanteric)

46
Q

What is the most common type of hip dislocation and how is it caused?

A

Posterior hip dislocation due to car accident

47
Q

Which way does the femoral head move in a hip dislocation?

A

Inferiorly and posteriorly, tearing joint capsule.

48
Q

What is the clinical relevance of a posterior and inferior hip dislocation?

A

Limb shortening and medial rotation

Sciatic nerve damage may also occur

49
Q

What is an anterior hip dislocation caused by?

A

Injury that forces hip into abduction, extension and lateral rotation.

50
Q

What is a fracture dislocation of the hip joint?

A

Femoral head dislocates, carrying acetabular bone fragment and acetabular labrum with it

51
Q

IMPORTANT

Why does shortening of the limb occur in femoral neck fractures?

A

The strong muscles of the thigh (flexors, adductors and extensors) pull the distal fragment of the femur upwards; thus the leg is shortened.

52
Q

IMPORTANT

Why does lateral rotation occur in femoral neck fractures?

A
  • Fractured neck allows head of femur to move independently of hip joint
  • Axis of rotation now passes through greater trochanter and long shaft rather than head
  • Iliopsoas, normally acting as medial rotator, now acts as lateral rotator
53
Q

Why do you get medial rotation in dislocated hip?

A

The anterior parts of the gluteus medius and minimus pull on the greater trochanter and cause the thigh to rotate medially.

54
Q

Why do you get limb shortening in posterior dislocation of hip joint?

A

During hip dislocation the head of the femur is pulled upwards by the strong flexor muscles (iliacus & psoas major), extensors (gluteus maximus and hamstrings) and adductors causing limb shortening.
The femoral head is pushed backwards over the posterior margin of the acetabulum and comes to lie on the lateral surface of the ilium.