Hip Dysplasia

Question 1

How are hip dysplasia patients most likely to present?

Answer 1

4-12 months at first presentation - hip laxity
Second phase of presentation at adult - arthritis in hips
Rarely limping as dysplasia often bilateral (more common difficulty getting up etc.)

Question 2

What might we feel on orthopaedic examination?

Answer 2

Muscle atrophy (esp. around quadriceps)
Pain on hip extension
Crepitus
Clunking

Question 3

What radiograph views do we take to check for hip dysplasia?

Answer 3

Ventrodorsal extended
Frog leg
Lateral pelvis

Question 4

How can we palpate for hip dysplasia?

Answer 4

Ortolani test
Dog in dorsal recumbency, legs abducted
Clunks in/out at angle of subluxation/reduction

Question 5

What treatment options do we have for hip dysplasia?

Answer 5

Non-surgical (conservative)
Myotomies
Growth plate fusion
Osteotomies
THR
Femoral head and neck excision

Question 6

Describe conservative management of hip dysplasia.

Answer 6

Restricted exercise - leash only, regular short walks
Hydrotherapy
Controlling food intake to slow growth
NSAIDs and other medications

Question 7

Describe juvenile pubic symphysiodesis.

Answer 7

Iatrogenic closure of pubic symphysis
Electrocautery to create thermal necrosis
Acetabular ventroversion
Must be done during early growth phase!
Increases dorsal acetabular cover of femoral head

Question 8

Describe triple/double pelvic osteotomy.

Answer 8

6-7 months old, no DJD
Good clunk on Ortolani test
Increases dorsal acetabular cover of femoral head

Question 9

What complications can we see with a triple pelvic osteotomy?

Answer 9

Screw pullout
Screw breakage
Usually do not need correction - 90% success
May still need salvage surgery later in life e.g. THR

Question 10

Describe femoral head and neck excision.

Answer 10

Salvage procedure
Pseudoarthritis
Encourage exercise after surgery!

Question 11

Describe denervation.

Answer 11

Denervation of dorsal acetabulum
Provides pain relief

Question 12

What are the aims of a THR?

Answer 12

Pain relief
High level function

Question 13

What are the indications for a THR?

Answer 13

Hip arthritis
Hip dysplasia

Question 14

What is an uncemented THR?

Answer 14

Biological fixation
Relying on bony regrowth

Question 15

Describe a THR.

Answer 15

Replace femoral head and neck and acetabulum:
Craniolateral approach to hip
Femoral head excision
Ream acetabulum
Ream femur
Cement acetabulum
Cement femur
Place “femoral head”
Reduce hip
Bacterial swab
Suture joint capsule
Routine closure

Question 16

What immediate post-op radiographs should we take of a THR?

Answer 16

Positioning - femoral stem, acetabulum
Cement fill

Question 17

What long-term monitoring radiographs should we take of a THR?

Answer 17

Positioning - femoral stem, acetabulum
Periosteal reaction
Cement/bone interface

Question 18

What complications are associated with a THR?

Answer 18

Fracture
Loosening
Dislocation
Infection
Subsidence (sinking deeper into bone - reduced by bolted uncemented THRs)
Cement granuloma
Neurological

Question 19

When would we use an uncemented THR?

Answer 19

Tapered femurs to reduce subsidence and fracturing
Can use uncemented acetabulum and cemented femoral head and neck

Question 20

What post-op exercise should be provided for THR patients?

Answer 20

Strict rest for 6 weeks
Cage rest
Lead walks only
Avoid slippery surfaces
Avoid jumping