Hip

Question 1

Describe positive trendelenberg sign

Answer 1

Fall on side with leg raised due to contralateral superior gluteal nerve damage/adductor weakness

Question 2

What movements cause femoroacetabular impingement

Answer 2

Flexion
Adduction
Internal rotation

Question 3

4 X-ray features of OA

Answer 3

Loss of joint space
Osteophytes
Subchondral cyst
Sclerosis

Question 4

Describe positive result for Thomas test

Answer 4

Hand under patients lumbar spine
Ask patient to keep one leg flat while bringing other knee to chest (straightens lumbar lordosis)
Positive if can’t keep leg flat on table

Question 5

What does positive Thomas test mean

Answer 5

Fixed flexion deformity I.e inability to extend at hip (iliopsoas contracture)

Question 6

Describe events following AVN

Answer 6

Hip works normally for a few days but over time there is no bone turnover so hip deteriorates
Microfractures of hip
Cartilage unaffected as gets nutrition from synovial fluid

Question 7

Causes of AVN

Answer 7

Trauma
Alcohol
Steroids
Immunosuppression
Liver disease
Idiopathic

Question 8

Describe perthes disease

Answer 8

AVN before growth plate fusion

Necrosis of epiphysis makes it softer so femoral head flattens

Question 9

Management of perthes disease

Answer 9

Stop weight bearing to reestablish blood flow

Question 10

Pathophysiology of septic arthritis

Answer 10

Infection of a joint
Pus in the synovial fluid so no nutrition to cartilage
Cartilage becomes necrotic and lose function of joint completely, needs replacement

Question 11

Symptoms of septic arthritis

Answer 11

Severe pain
Can't weight bear
ROM significantly reduced
Patient won't let you examine them
Temperature over joint 
Tense effusion

Question 12

Investigations for septic arthritis

Answer 12

Bedside: baseline obs to screen for sepsis
Bloods: emergency cultures, FBC, CRP, U+E, LFT
Imaging: US
Special tests: joint aspiration + MCS

Question 13

Treatment for septic arthritis

Answer 13

Orthopaedic review
Urgent arthrocentesis, washout and debridement
ABx (after blood cultures) for 2 weeks IV and then switch to oral for 2-4 further weeks if improving

Question 14

Risk factors for septic arthritis

Answer 14

Preexisting joint pathology (RA!)
Diabetes
Immunosuppression
IVDU
CKD
Prosthetic joint
Recent joint surgery

Question 15

Common causative organisms of septic arthritis

Answer 15

Staph aureus
Strep
Staph epidermidis
Neisseria gonococcus
Gram negative bacilli

Question 16

Describe congenital hip dislocation

Answer 16

Bilateral posterior hip dislocation
Trendelenberg gait positive due to weak adductors
Needs intervention to make femoral head grow into acetabulum e.g pavlik harness
Early arthritis

Question 17

Describe a SUFE

Answer 17

Slipped upper femoral epiphysis
Femoral head slips off epiphysis, needs pinning in place
Often occurs bilaterally so during surgery can pin other leg prophylactically

Question 18

Describe X-ray appearance of metastatic bone cancer

Answer 18

Irregular lytic area
No sclerotic edge
Fractures likely

Question 19

Management of metastatic bone cancer

Answer 19

Bridge lesion with nail to reduce chance of fracture

Radiotherapy if no risk of fracture

Question 20

Describe X-ray appearance of osteosarcoma

Answer 20

Sclerotic lesion
New bone formation outside of bone
Common in end of femur

Question 21

Describe lipohaemarthrosis

Answer 21

Follows a fracture
Bone marrow fat and blood inside joint
Fat floats on top of blood so in a supine X-ray, there is a hyperdense flat line in joint

Question 22

Describe osteochondritis dissecans

Answer 22

Affects teenage to middle aged
A small segment of bone begins to separate from its surrounding region due to a lack of blood supply
Bone and the surrounding cartilage begin to crack and loosen
Can heal by itself or can detach and float inside joint