Hip (Session 3)

Question 1

Which muscles in the hip does the superior gluteal nerve supply?

Answer 1

Hip ABDUCTORS: Gluteus medius and minimus

Question 2

How can the superior gluteal nerve get injured?

Answer 2

Complication of hip surgery

Buttock injections

Greater trochanter fracture

Hip dislocation

Question 3

What is the ‘Trendelenburg sign’?

Answer 3

Clinical sign- superior gluteal nerve damage. If patient standing on one leg and hip drops on the raised leg- as gluteus medias and minimum of other limb not contracting so pelvis not supported on that side

Question 4

Where do the hamstring muscles originate?

Answer 4

ischial tuberosity

Question 5

What population is most commonly affected by osteoarthritis?

Answer 5

Elderly (20-30% of people over 70 suffer from OA of hip)

Question 6

Define osteoarthritis.

Answer 6

1) Degenerative disorder arising from breakdown of articular hyaline cartilage
2) Clinical syndrome comprising joint pain and functional limitation+ reduced quality of life
3) chronic disease of MSK system= non inflammatory

Question 7

What are the most common joints affected by osteoarthritis?

Answer 7

Hips, knee, cervical spine, lumbar spine, small joints in hands

Question 8

What is ankylosis?

Answer 8

Bony fusion across a joint

Question 9

What’s the difference between primary and secondary OA?

Answer 9

Primary: cause is unknown, Secondary: known cause

Question 10

What are some risk factors for primary osteoarthritis?

Answer 10

Age, female sex, ethnicity, genetics, nutrition

Question 11

What are some specific causes of secondary osteoarthritis?

Answer 11

Obesity, trauma, malalignment, infection, inflammatory arthritis (e.g. rheumatoid), metabolic disorders, haematological disorders, endocrine abnormalities

Question 12

What are some symptoms of osteoarthritis?

Answer 12

Deep+ aching joint pain

Reduced range of motion

Crepitus (grinding)

Stiffness during rest

Question 13

How does excessive/uneven loading of the joint increase someones risk of osteoarthritis?

Answer 13

Damages hyaline cartilage- hyaline cartilage= swollen (increase proteoglycan synthesis by chondrocytes)- attempt to repair cartilage- eventually cartilage softens and loses elasticity- eroded down to bone, loss of joint space

Question 14

What is eburnation?

Answer 14

Subchondral bone–>thicker denser bone

Process in which subchondral bone responds to cartilage surface changes

Question 15

What are the 4 cardinal signs of OA on an X-ray?

Answer 15

LOSS:

Loss of joint space

Osteophytes

Subchondral sclerosis

Subchondral cysts

Question 16

In what population is osteoarthirits of the hip most common?

Answer 16

Males over 40

Question 17

What symptoms will be experienced by those sufferring from osteoarthritis of the hip? (5)

Answer 17

1. Joint stiffness
2. Pain in:
   
   1. Hip
   2. Gluteal region
   3. Groin region–> radiating to knee (via obturator nerve)
3. Mechanical pain
4. Crepitus
5. Reduced mobility

Question 18

How is osteoarthirits of the hip diagnosed?

Answer 18

Clinical presentation

Supported by x-ray changes

Question 19

How is osteoarthritis of the hip treated? (conservative) (9)

Answer 19

1. Weight reduction (if overweight)
2. Activity modification
3. Walking stick/frame -reduce load
4. Muscle strengthening exercises/orthotic footwear
5. Analgesia
6. Anti-inflammatories (NSAIDs)
7. Nutritional supplements
8. Steroid injections-reduce swelling
9. Hyaluronic acid injections- increase lubrication

Question 20

What is the only ‘cure’ for hip osteoarthritis?

Answer 20

Total hip replacement

Question 21

Roughly how many hip replacements are performed in the UK each year and what is the average age?

Answer 21

about 100,000

Average age: 68yrs

Question 22

What is a fractured neck of femur (NOF#) defined as? (as in where fracture is classified as NOF#)

Answer 22

• Fracture of proximal femur
• Up to 5cm below lesser trochanter

Question 23

What are the 2 types of neck of femur fractures?

Answer 23

Intracapsular

Extracapsular

Question 24

What can the extracapsular fractures be divided into?

Answer 24

1. Intertrochanteric
2. Subtrochanteric

Question 25

Why is there a high risk of avascular necrosis with an intracapsular #NOF, particularly if the fracture is displaced?

Answer 25

* Fracture=likely to disrupt: **Medial femoral circumflex artery (MFCA)** * Artery of *ligamentum teres*- unable to sustain metabolic demands of *femoral head*

Question 26

Which populations do intracapsular and extracapsular fractures commonly affect?

Answer 26

**Intracapsular:** * More common in elderly * (esp post-menopausal women w./ osteoporotic bone) **Extracapsular:** * Young and middle aged

Question 27

What are the common mechanisms of injury for intracapsular and extracapsular fractures?

Answer 27

**Intracapsular**: Minor fall **Extracaspsular**: Significant trauma eg road traffic collision

Question 28

Why is a displaced intracapsular fracture in an older person usually treated by surgical replacement of: * **Hemiarthroplasty** (Femoral head only) * **Total hip replacement** (Femoral head and acetabular cup)

Answer 28

High risk of avascular necrosis

Question 29

What is the prognosis like following a #NOF?

Answer 29

* 20% one year **mortality** (many of patients=elderly and have co-morbidities) * 30% one-year post #NOF **permanent disability** * 40% unable to **walk independently** * 80% unable to carry out **at least one independent activity of daily life**

Question 30

What are the symptoms of a neck of femur fracture?

Answer 30

* Reduced mobility * Pain (may be felt in hip, groin, knee)

Question 31

How will a patient with a neck of femur fracture present if the fracture is displaced? (position of leg)

Answer 31

Affected leg: * Shortened * Abducted * Externally rotated Exacerbation of pain on: * Palpation of greater trochanter * Rotation of hip

Question 32

Why is the hip shortened, abducted and externally rotated in a displaced #NOF?

Answer 32

* Shaft of femur can now move independently to hip joint * Short lateral rotators of hip: piriformis, obturator internus etc contract and **laterally rotates femoral shaft** * Iliopsoas pulls on lesser trochanter- **laterally rotates femoral shaft** * Strong abductors attach to greater trochanter **abduct** femur distal to fracture site * Rectus femoris, adductor magnus, hamstring muscles- pull distal fragment of femur upwards- **shorten** limb

Question 33

Define 'dislocation of the hip'.

Answer 33

Head of femur- fully displaced out of cup-shaped acetabulum of pelvis

Question 34

What are the 2 main causes of hip dislocations?

Answer 34

1. **Congenital** 2. **Traumatic**

Question 35

What is DDH? (MSK)

Answer 35

**Developmental dysplasia of the hip** (can be congenital/develop after birth)

Question 36

In what population is an acute traumatic hip dislocation most commonly seen?

Answer 36

16-40 year olds | (in high speed road traffic collision)

Question 37

What % of hip dislocations are posterior?

Answer 37

90%

Question 38

What is the most common cause of a posterior hip dislocation?

Answer 38

Knee impacting dashboard during road traffic collision

Question 39

How will the patients affected limb be held is they have experienced a posterior hip dislocation?

Answer 39

1. Flexed 2. Adducted 3. Internal (medial) rotation (Due to: Femoral head lying on surface of ilium Head of femur pulled up by strong extensors and adductors of hip Anterior fibres of glut medius and minimus pull on greater trochanter- cause femur to rotate internally

Question 40

In what % of cases of posterior hip dislocations is sciatic nerve palsy present?

Answer 40

8-20% of cases

Question 41

What position is the limb held in in an anterior dislocation?

Answer 41

External rotation Abduction Slight flexion

Question 42

Why is a central dislocation of the hip a life threatening injury?

Answer 42

* Head of femur driven into pelvis through acetabulum * Always= **fracture dislocation** * Femoral head=palpable on rectal examination * High risk- intrapelvic haemorrhage * disruption of pelvic venous plexuses