Hip Flashcards
What are the surgical disorders of the hip?
Hip dysplasia
Coxofemoral luxation
Leg-calve perthesis disease
What is the pathogenesis of hip dysplasia ?
Abnormal development of coxofemoral joint resulting in joint laxity
— laxity leads to malarticulation and DJD
Associated with disparity of growth of muscle mass vs skeletal structures
—affected dogs have rapid skeletal growth and delayed muscle growth
Bony changes occur because of lack of congruity between femoral head and acetabulum
What is the signalment with hip dysplasia?
Large breed
Juveniles present with joint laxity
Mature patients present with DJD and osteoarthritis
What is a common history seen in animals with hip dysplasia ?
Exercise intolerance
Difficulty rising
Intermittent/continual lameness
Sits funny/ falls to the side
Bunny hops
Takes stairs with both legs together
Slow, chronic onset
What do you see in the early phase of hip dysplasia during an orthopedic exam?
Early phase — lame, pain on extension of hip joints
Bunny hopping, straight stifles, throw weight forward, head and neck extended, narrow base rear, wide Base front
Muscle atrophy and reluctant to rise
What do you see during an orthopedic exam in late phase hip dysplasia?
Restricted extension, muscle atrophy, pain on extension, crepitus
What is the Ortolani sign?
Dog is in dorsal recumbency with femurs at 90 degree angle to table
Subluxation femoral head dorsally by pressure on stifle joint (adduct slightly)
Maintain pressure white slowly abduct stifle
Palpating (and hearing) head return to acetabulum = positive Ortolani sign
The greater the angle of reduction, the greater the degree of joint laxity
The pain associated with hip dysplasia in a juvenile is caused by?
Exposure of pain receptors in subchondral bone and joint capsule
In older dogs, pain is secondary to osteoarthritis
What radiographic changes are see in hip dysplasia?
Early stage - increased joint space, flattened acetabulum, coxa valga, osteophyte
Late stage - above +DJD
What is your DDX for hip dysplasia?
Neurological
Orthopedic
L-S instability
Herniated disc
Myelopathy
Bilateral CCL
T/F: medical managment is always the first line treatment in hip dysplasia
True
How can you medically manage a dog with hip dysplasia ?
Reduce food intake — keep dog lean (low fat and protein)
Managed exercise
Swimming and controlled long slow leash walks
Alleviate pain (passive and active exercises and NSAIDS)
Maintain strength and joint motion
You have a 15week old puppy with hip dysplaia. What surgical intervention would be appropriate ?
Juvenile pubic symphysiodiesis (JPS)
— alters growth of pelvis and degree of ventroversion of acetabulum
What surgical management for hip dysplasia is appropriate in a 6month dogs without radiographic evidence of DJD?
Triple pelvic osteotomy
—> osteotomy of pubis, ischium, and ileum
Ileum is then fixed with an angled TPO plate to achieve axial rotation of the acetabulum
In what cases in triple pelvic osteotomy provide the most favorable prognosis?
Stress radiographic evidence of subluxation
Minimal to no DJD
Angle of reduction <30degrees and angle of subluxation <10degrees
Solid distinctive reduction of femoral heal (positive Ortolani sign)
What are surgical procedures for hip dysplasia that can be done in mature dogs?
Total hip replacement
Femoral head and neck ostectomy
T/F: total hip replacement for hip dysplaia is only done as a salvage procedure after non-response to medical managment
True
What are the two types of total hip replacement?
Cemented and cementless prosthesis
T/F: large and active dogs have better function with total hip replacement than with FHO
True
What are complications to THR?
Dislocation PO
Infection
Loosening —cemented
Failure of ingrowth —cementless
Femur fracture
What is a femoral head and neck ostectomy?
Removal of the head and neck of femur with saw or osteotome
Pesudoarthrosis is formed using gluteal muscles and tendons to support weight
What is the approach to the hip joint when doing a FHO?
Craniolateral
What is the prognosis for surgical correction of hip ?
TPO- long term function good to excellent
— progressive degenerative changes
THR - excellent to normal function unless complication
FHO- smaller patients have better results
What is the most commonly luxated joint in dog and cat
Coxofemoral
What is the cause of coxofemoral luxations?
Motor vehicle accidents
Associated with contralateral pelvic or long bone fracture
Associated with thoracic injury
Silent trauma — eg fell down stairs
T/F: coxofemoral luxation causes an acute, unilateral weight bearing lameness
False
Acute unilateral NONweightbaring lameness
What are your DDX for coxofemoral luxation?
Fracture of femoral head or neck
Slipped capital physis or avulsion fracture
Fracture of acetabulum
Hip dysplasia and degenerative joint disease (DJD)
What are the 3 stabilizers of the hip joint?
Ligament of head of femur
Joint capsule
Dorsal acetablular rim
What muscles attach to the greater trochanter of the femur, which requires a tension band when repairing with osteotomy
Middle and deep gluteals
T/F: most coxofemoral luxations are in the craniodorsal direction
True
This this consisted with a (craniodorsal or caduoventral) coxofemoral luxation?
Non-weight bearing lameness Greater trochanter difficult to palpate Hold leg out and flexed Stifle internally rotated Affected limb longer on extension
Caudoventral luxation
This this consisted with a (craniodorsal or caduoventral) coxofemoral luxation?
Affected leg held in relaxed extension with foot beneath the body and stifle externally rotated
Affected leg is shorter on extension of hip
Pain and crepitus on palpation
Craniodorsal
T/F: Ehmer slings should be used to stabilize reduced caudoventral coxofemeral luxation
True
Place in hobbles
T/F: Ehmer sling should be used to stabilize a reduced craniodorsal coxofemeral luxation
True
7-10days post reduction
How do you do a closed reduction of a craniodorsal coxofemoral luxation?
Grap tarsus and externally rotate the limb
Apply distal traction to bring head of femur below the acetabular rim
When head clears acetablulum, internally rotate limb
Place thumb of opposite hand on ventral rim acetabulum and index finger on trochanter
Apply pressure while putting joint through ROM to clear out debris from joint
When is open reduction indicated for coxofemoral luxation?
Avulsion of fovea capitis
Closed reduction unsuccessful
Unable to maintain closed reduction
What are the two possible approaches to open reduction of coxofemoral luxation?
Cranial -lateral
Dorsal approach by osteotomy of greater trochanter
What are the types of repair can you do on coxofemoral luxations
Reconstructions
— capsulorrhahy
—translocation of greater trochanter
Prosthetic implant
— prosthetic capsule made of suture
—toggle pin (only procedure that does not required coaptation)
Total hip replacement
Femoral head and neck osteotomy
How s a prosthetic capsule made?
Hole drilled transversely across neck of femur
Bone screws and washers are inserted into dorsal acetabulum
Non absorbable suture material is placed through hole and around screws in figure 8 pattern
How is a toggle pin/rod made?
Toggle with non-absorbable suture attached into acetabular fossa
Suture material is drawn through tunnel drilled in femoral neck
Suture is secured on lateral side of femur
What is the prognosis for closed and open coxofemoral luxation reductions?
Closed - 50%
Lower with dysplasia or previous trauma
Open - 85-50% with good to excellent limb function
What is legg-perthes disease?
Aseptic necrosis of the femoral head
Possible causes of legg-perthes disease?
Hereditary
Infraction of femoral head
Pathogenesis of legg-perthes disease?
Blood supply to femoral head is occluded
Aseptic necrosis of subchondral bone followed by cartilage collapse
Incongruity resulting in DJD and lameness
Signalment associated with legg-perthes disease?
Young (prior to capital physis closure)
Toy and small breed
6-7months
Diagnosis of legg-perthes disease?
Pain on manipulation of hip
Chronic — muscle atrophy and creptius, decreased ROM
Rads
—deformity of femoral head
—shortening and thickening of femoral neck
—foci of bone opacity in epiphysis
Treatment for legg-perthes disease?
Femoral head and neck excision
Surgery as early as possible
Need pain management and physical therapy
Prognosis - good
