MSK 6 Hips cruciate MPLs Flashcards
What is the primary difference in age between young and old hip dysplasia?
5-12 months for young hip dysplasia; variable onset in mature dogs (3 years+).
What are the common clinical signs of both young and old hip dysplasia?
- Pain with hip extension
- Reduced range of motion (ROM)
- Reluctance to walk, run, jump, climb
- Exercise intolerance
- Reduced muscle mass
What is a key radiographic difference between young and old hip dysplasia?
No OA changes have developed yet in young; moderate to severe OA changes on radiographs in old.
What is Juvenile Pubic Symphysiodesis?
A procedure involving thermal necrosis of the pubic physis to rotate acetabuli over the femoral heads, best done at 14-22 weeks.
What are the ideal candidates for Triple or Double Pelvic Osteotomy?
- Patients with clinical signs of hip dysplasia
- Confirmed laxity with no OA changes
- Less than 10 months to 1 year old
What are common complications of Total Hip Replacement?
- Luxation
- Femur fracture
- Fractured acetabulum
- Cup avulsion
- Aseptic loosening
What is the primary goal of Femoral Head and Neck Excision?
To eliminate pain from bone-on-bone contact.
What is the radiographic feature known as ‘Morgan’s line’?
Caudolateral curvilinear osteophyte (CCO) seen on the femoral neck in dogs 18 months or older.
Define Hip Dysplasia.
A developmental disorder of increased laxity in the hip joint causing pain and injury to periarticular structures, leading to eventual degenerative joint disease.
What are the two most common types of meniscal injuries?
- Bucket handle of medial caudal meniscus
- Radial tears of lateral meniscus
What predisposes immature animals to Cranial Cruciate Ligament (CCL) injuries?
Avulsion of the ligament from femoral or tibial attachment sites due to trauma.
What are the pros of Extracapsular repair for a 35kg overweight lab?
- Cheaper
- More accessible for general practitioners
- Something is better than nothing
What is the purpose of Tibial Plateau Leveling Osteotomy (TPLO)?
To reduce the tibial plateau angle so that there is no forward tibial thrust when weight is placed.
What are the complications associated with Tibial Tuberosity Advancement (TTA)?
Higher risk of complications compared to other techniques, relies on the body forming fibrous scar for ongoing stability.
What are the characteristics of Grade 4 luxating patella?
- Marked femoral varus
- Proximal tibial valgus
- Severe bony/ligamentous deformities
What is the significance of the ‘puppy line’ in radiographic studies?
An indistinct radiodense line on the femoral neck in dogs younger than 18 months, self-limiting and not clinically significant.
What factors contribute to the pathogenesis of Hip Dysplasia?
Complex mix of many genes and environmental factors, including rapid growth, obesity, and hormonal influences.
List the grading system for cranial cruciate ligament laxity.
- Grade 1: Mild laxity, relocates spontaneously
- Grade 2: Spontaneously luxates and relocates
- Grade 3: Permanently luxated but can be relocated
- Grade 4: Permanently luxated, unable to relocate
What are common surgical procedures for patellar luxation?
- Tibial crest transposition
- Wedge or block sulcoplasty
- Medial desmotomy
What is the primary risk when performing a medial desmotomy?
Not being effective or causing overtightening, leading to lateral luxation.
What are the radiographic characteristics of Grade 4 luxating patella?
Marked femoral varus, femoral torsion (<27 degrees), proximal tibial valgus, tibia rotated 60-90 degrees relative to the sagittal plane, severe bony/ligamentous deformities (OA/DJD), likely concurrent cranial cruciate ligament signs (fat pad compression, osteophytes, joint effusion), shallow trochlear groove with poorly developed or absent medial ridge, poorly developed medial femoral condyle, patella on the medial aspect
OA = Osteoarthritis, DJD = Degenerative Joint Disease.
What surgical procedures are indicated for Grade 4 luxating patella?
Corrective osteotomies of femur, tibial leveling plateau osteotomy with internal tibial torsion correction +/- derotational proximal tibial osteotomy, tibial tuberosity transposition/advancement
These procedures aim to correct the underlying bone deformities contributing to the luxation.
What factors affect the prognosis for luxating patella cases treated surgically?
- Grade of luxation: good for 2-3, fair to good for 4
- Severe grade 4 with DJD, cartilage loss, muscle atrophy, and rotational deformity: grave to poor prognosis
- Bigger dogs (20kg +) had higher rates of complications/reluxations
- Needing both tibial and femoral surgical corrections leads to higher complication rates
- If distal femoral varus is NOT addressed
These factors highlight the importance of thorough preoperative assessment.
What are the primary stabilizers of the coxofemoral joint?
- Femoral head ligament (capital ligament)
- Joint capsule
- Dorsal acetabular rim
These structures help maintain the integrity and stability of the hip joint.
List the secondary stabilizers of the coxofemoral joint.
- Acetabular labrum and transverse acetabular ligament
- Hydrostatic pressure created by joint fluid
- Periarticular muscles (deep, middle, and superficial gluteal muscles)
Secondary stabilizers provide additional support but are not the primary means of stabilization.
What are the physical exam findings for craniodorsal luxations?
- Pain in hip region
- Non-weight bearing lameness
- External rotation and adduction of the affected limb
- Asymmetry of hips
- Increased distance between the greater trochanter and ischiatic tuberosity
- Greater trochanter is equidistant between ischiatic tuberosity and cranial dorsal iliac spine
- Apparent shortening of affected limb
- Crepitus in hip joint
These findings help differentiate craniodorsal luxations from other types of luxations.
What are the steps for closed reduction of a craniodorsal luxation?
- General anesthesia
- X-rays to confirm and rule out fractures
- Lateral recumbency affected side up
- Use a towel or rope through inguinal area to stabilize the pelvis
- Disengage femoral head from dorsal acetabular rim by holding hock and stifle and externally rotating the limb
- Apply traction in a distocaudal direction to align femoral head over acetabulum
- Rotate the limb internally and abduct to seat the femoral head into the acetabulum
- Press on the greater trochanter to keep it in place and take the leg through full ROM
- X-rays at the end to confirm position
- Use EHMER sling
This technique helps restore the normal anatomy of the hip joint.
When is surgical intervention indicated over closed reduction for luxation?
- Acetabular or femoral head fractures present
- If reluxation occurs after closed reduction
- Concurrent injuries require immediate return of hip function
- Chronic luxation
- Visual inspection of cartilage is advised if it has been weeks
- Muscle contracture and unable to reduce
- Changes or hematoma within acetabulum
- Dysplastic changes in the joint on radiographs
Surgical options may provide better outcomes in complex cases.
What are the potential complications of hip toggle surgery?
- Too loose or too tight
- Infection
- Implant failure, premature suture failure
- Injury to rectum
- Sciatic nerve damage
- Articular cartilage damage, OA/DJD
Awareness of these complications is crucial for postoperative management.
What are the differentials for hip-related issues?
- Femoral neck fracture
- Hip luxation
- Acetabular fracture
- Iliopsoas strain
- Femoral neck necrosis
These differentials help guide diagnostic and treatment strategies.
What is the most common injury of the physes of the proximal femur?
Type 1 Salter Harris ‘Slipped cap’
This type of fracture often requires urgent surgical stabilization.
What are the open approaches for capital physeal fractures?
- Craniolateral approach
- Dorsal approach via osteotomy of greater trochanter (<5 months)
- Dorsal approach via tenotomy of gluteal muscles (<3-5 months)
The choice of approach depends on the age of the animal and the specifics of the injury.
What are the characteristics of the complex arterial network around the femoral neck?
- Extraosseous: lateral and medial circumflex femoral arteries, caudal and cranial gluteal arteries, iliolumbar arteries
- Vascular ring around base of femoral neck with branches penetrating the physis
- Single extracapsular vascular ring is highly susceptible to vascular insult
Understanding the vascular supply is important for surgical planning.
What are the outcomes of a conservative approach to treating capital physeal fractures?
Poor functional outcomes; chronic discomfort, lameness, disuse atrophy, secondary DJD, pseudarthrosis with progressive cervical resorption
These outcomes underscore the need for timely surgical intervention.
What are the preferred fixation methods for primary repair of capital physeal fractures?
Multiple Kirschner pins or small diameter Steinman pins
These methods avoid compression of the physis and allow for continued growth.
What are the potential consequences of premature closure of the physis?
- Shortened femur by 25%
- Damage to blood supply
- Abnormal development of femoral head and neck
- Development of DJD
- Infection
- Loosening pins/K wires
- Iatrogenic fracture
These complications highlight the importance of careful surgical technique.
What is capital physeal dysplasia?
Spontaneous separation of physis after physeal closure, occurring more in cats than dogs
Young, overweight, castrated male cats are overrepresented, and early neutering may be a factor.
What is the recommended approach for salvage in cases of capital physeal dysplasia?
- FHNE
- Total Hip Arthroplasty
The choice depends on the specific case and financial considerations.
Avascular necrosis femoral head underlying cause?
Dont know what causes it
blood supply to developing femoral head fragile- intracapsular blood supply, so very susceptible to damage, injury, disease
signalment and presentation for femoral head necrosis in dogs
5-10mths age
certain breeds - poodles, terriers, westies, mini pins,
unlateral, sometimes bilateral
hip pain/lameness
mostly insidious onset, occasionally sudden onset
Standard hip xray views
VD extended
Frogleg
Lateral
Pathophysiology FH necrosis
Not sure of what initially causes it
Results in necrosis and collapse of subchondral bone
Joint surface eventually collapses under weight bearing
Articular cartilage collapses, remodelling of femoral neck
Radiographic signs FH Necrosis
Femoral neck sclerosis/thickening
Early - joint space looks a bit wider earlier
then moth eaten appearance,
then femoral head collapses
changes can be very subtle
Treatment options FHN
Total hip is gold standard
or FHNO
