Hip

Question 1

What is hip dysplasia?

Answer 1

abnormal development of the coxofemoral joint

Question 2

Describe the pathogenesis of hip dysplasia

Answer 2

• abnormal development leads to laxity
• capital ligament edema and thickening, increased joint fluid
• capital ligament stretches
• subluxation occurs with activity
• force on the abnormal hip causes wear, which results in osteoarthritis

Question 3

What factors contribute to expression of hip dysplasia?

Answer 3

• genetics
• pelvic muscle mass
• body weight
• nutrition (Ca, vitamin D, energy)

Question 4

What is the typical history associated with hip dysplasia?

Answer 4

• exercise intolerance
• buny-hop gait
• difficulty rising/stiff after rest
• reluctant to climb stairs or jump
• sits to the side, avoiding hip flexion

Question 5

What is seen on physical exam of a dog with hip dysplasia?

Answer 5

• forward weight shift stance
• hip sway gait
• difficulty rising/sitting
• muscle atrophy
• pain on extension of hip

Question 6

Describe the Ortolani test

Answer 6

• requires sedation
• dorsal or lateral recumbency
• one hand on stifle, one dorsal to pelvis
• push stifle proximally to subluxate
• slowly abduct stifle
• palpable/audible clunk indicates a positive test

Question 7

What are the radiographic findings of a dog with hip dysplasia?

Answer 7

• Morgan’s line: linear density between femoral head and greater trochanter
• subluxation with < 50% acetabular coverage
• coxa valga and thickening of femoral neck
• flattening and sclerosis of femoral head

Question 8

How is hip dysplasia treated medically?

Answer 8

• lower Ca/vitamin D/energy diet in puppies
• weight management
• exercise modulation
• physical therapy
• NSAIDs

Question 9

Which surgical procedures are used to manage hip dysplasia?

Answer 9

• juvenile pubic symphiodesis
• triple pelvic osteotomy
• femoral head ostectomy
• total hip replacement

Question 10

Describe the JPS procedure

Answer 10

• corrective procedure
• fuse pubic symphysis
• rolls acetabulum ventrally

Question 11

Describe the TPO procedure

Answer 11

• corrective procedure
• improve femoral head coverage
• rotate acetabulum dorsally
• osteotomy of pubis, ischium, and ilium
• fixation of ilium with angled plate

Question 12

Describe the THR procedure

Answer 12

• salvage procedure

- replace joint with prosthesis (femoral stem, acetabular cup)

Question 13

Describe the FHO procedure

Answer 13

• salvage procedure

- removal of entire femoral neck and head

Question 14

What is the most common cause of coxofemoral luxation?

Answer 14

trauma

Question 15

Describe a caudoventral coxofemoral luxation

Answer 15

• excessive abduction of the limb
• femoral head trapped ventral to ischium
• leg held abducted and internally rotated
• affected limb is longer

Question 16

How is a caudoventral coxofemoral luxation treated?

Answer 16

• closed reduction
• open reduction if needed
• general anesthesia needed

Question 17

What needs to be done post-reduction for a caudoventral luxation?

Answer 17

• put joint through full ROM to clear debris
• apply hobbles for 10-14 days
• ehmer sling is contraindicated

Question 18

Describe a craniodorsal coxofemoral luxation

Answer 18

• most common
• greater trochanter displaced dorsally
• affected leg held in relaxed extension
• limb adducted and externally rotated
• affected limb is shorter

Question 19

What needs to be done post-reduction for a craniodorsal luxation?

Answer 19

• put joint through full ROM to clear debris
• test stability
• ehmer sling for 10-14 days

Question 20

What are the indications for an open reduction on a coxofemoral luxation?

Answer 20

• pelvic/acetabular fracture
• femoral fractures
• unstable closed reduction
• recurrent closed reduction

Question 21

What surgical treatments are used for coxofemoral luxations?

Answer 21

• capsulorrhaphy
• prosthetic capsule
• toggle pin
• salvage: FHO, THR

Question 22

What is the prognosis for coxofemoral luxations?

Answer 22

• closed reduction more successful with recent injury

- open reduction good to excellent