Hip Disorders

Question 1

Osteoarthritis pathology

Answer 1

Excessive loading of joint
= Breakdown of articular cartilage
Increased proteoglycan from chondrocytes to try and repair
Flaking and fibrillation of cartilage (replaced by fibro)
Erosion of cartilage

Question 2

Primary osteoarthritis

Answer 2

Cause unknown
Risk factors:
Age
sex (female > male)
Ethnicity 
Nutrition
Genetics

Question 3

Secondary osteoarthritis

Answer 3

Causes:
Obesity 
Trauma (sports)
Malalignment - developmental dysplasia 
Infection
Inflammatory conditions
Metabolic disorders (gout)
Haematological disorders 
Endocrine abnormalities

Question 4

What does osteoarthritis lead to?

Answer 4

Subchondral sclerosis (increased cellularity so whiter on X ray)
Subchondral bone cysts
Osteophytes (extra bone)
Narrowing joint space

Question 5

Symptoms of osteoarthritis

Answer 5

Joint stiffness (getting out of bed or after a long time sitting)
Pain, swelling, tenderness of hip
Crepitus (crunching sound of bone on bone)
Reduced mobility of hip

Question 6

How is OA diagnosed?

Answer 6

Clinical signs and symptoms + Xray to confirm

Question 7

Management osteoarthritis (no op)

Answer 7

Activity modification
Weight loss
Stick
Physiotherapy

Question 8

Medications for OA

Answer 8

NSAIDS
COX-2 inhibitors
Nutritional supplements (glucosamine)

Injections:
Corticosteriods
Viscosupplementation (inject synovial fluid)

Question 9

Surgical procedures for OA

Answer 9

Total Hip replacement - reduce pain, improve wellbeing

Implant to replace damage surfaces (metal ball and socket joint down femur)

Question 10

Types of femoral fractures

Answer 10

Intracapsular - neck of femur (above intertrochanteric line)

Extracapsular - below intertrochanteric line

Question 11

Blood supply effects femoral fractures

Answer 11

Intracapsular - disrupts retinacular branches of medial circumflex femoral artery
Avascular necrosis of femoral head

(Ligamentum teres not enough to supply head of femur)

Question 12

Symptoms/signs of femoral fracture

Answer 12

Reduced mobility
Pain felt in hip, groin, knee

Signs:
Shortening and external rotation (legs flapped outwards)

Question 13

Why do legs externally rotate in NOF fracture?

Answer 13

Iliopsoas (flexes and externally rotates)

SHORT LATERAL ROTATORS contract (deep muscles)
Piriformis
Obturator internus
Superior and inferior gemelli
Quadratus femoris 
=Laterally rotate

Shortening - rectus femoris

Abduction - proximal gluteus medius and minimus

Question 14

Surgery for hip fracture

Answer 14

Hemiarthroplasty (femoral head replaced)

Total hip replacement (femoral head and acetabulum replaced)

Question 15

Causes of avascular necrosis

Answer 15

Mechanical disruption (fracture)
Alcoholism
Steroid use
Post trauma
Thrombosis 
Hypertension

Question 16

Hip dislocation types

Answer 16

90% posterior

Question 17

Types of people intracapsular and extracapsular occur in

Answer 17

Intracapsular - mostly elderly, post menopausal women after a fall

Extracapsular - young/middle aged (road traffic accident/rugby)

Question 18

Signs of posterior hip dislocation

Answer 18

Shortening
Flexion
Adduction 
Internal (medial) rotation 
Sciatic nerve palsy (foot drop)

Question 19

Why does shortening and internal rotation occur after posterior dislocation?

Answer 19

Head of femur pulled upwards by extensors (gluteus maximus and hamstrings)

Gluteus medius and minimus pull and cause internal rotation

Question 20

Anterior dislocation

Answer 20

External rotation

Femoral nerve palsy uncommon

Question 21

Central dislocation

Answer 21

Head of femur driven into pelvis
Femoral head palpable on rectal exam
High risk of haemorrhage