Lecture 7 2/3/25 Flashcards
What are the differentials for disorders of the coxofemoral joint?
-hip dysplasia
-legg-calve-perthes disease
-hip luxation
-OCD of femoral head
-trauma/fractures
What are the characteristics of hip dysplasia?
-abnormal development of the hip joint
-usually bilateral
-primarily in medium and large breed dogs
-initial laxity of the hip joint ultimately results in joint instability and secondary OA
What is the pathophysiology of hip dysplasia?
-inherited laxity of the hip joint leads to degenerative OA
-patient is born normal, laxity develops, and body attempts to stabilize hip
-polygenic mode of inheritance makes condition difficult to breed out
What is the prevalence of hip dysplasia?
-currently around 3.5% based on radiographic eval.
-likely artificially low since dogs with obvious disease may not submit radiographs
Which breeds have a predilection for hip dysplasia?
-newfoundland
-saint bernard
-old english sheepdog
-rottweiler
-german shepherd
-samoyed
-golden retriever
-alaskan malamute
-labrador retriever
What are the characteristics of OA progression associated with hip dysplasia?
-progression and severity of OA/clinical signs depends on interaction between dog’s genetic susceptibility and exposure to environmental factors
-neutered dogs are at greater risk for hip dysplasia than intact dogs; wait until sexual maturity to neuter in larger breeds
-diet plays a major role in hip dysplasia expression in young developing dogs
What are the characteristics of early evaluation and biomechanical changes associated with hip dysplasia?
-early diagnosis is crucial for saving the hip joint and keeping it as normal as possible
-primary clinical signs in young dogs are related to pain caused by joint instability
-repeated subluxation can cause acetabular microfractures and pain
-damage to the round ligament, articular cartilage, and joint capsule occurs
-instability develops between 4 and 12 months of age
What are the signs of hip dysplasia?
-difficulty rising
-decreased activity level
-“bunny hopping” gait
-difficulty using stairs
-loss of rear limb muscle mass
What indicates hip dysplasia during evaluation of the patient?
-pain with extension of hip joint
-palpation of joint laxity
-radiographs; may show subluxation
-crepitus
-decreased ROM
-waddling gait
-reluctance to stand
-hind limb muscle atrophy
-shoulder muscle hypertrophy
Why does pain initially decrease with the progression of hip dysplasia?
periarticular fibrosis improves joint stability, which can decrease pain temporarily before more progression occurs
What are the characteristics of the ortolani sign?
-classic method of assessing joint laxity in young dogs
-may require sedation if dog is tense
-generally not painful
-negative sign does not indicate lack of joint laxity; positive sign does indicate laxity
What is Barden’s maneuver?
-direct lateral displacement of the femoral head from acetabulum
-rarely done due to discomfort in both normal and and affected dogs
What is the barlow sign?
-allowing reduction of the laterally displaced femoral head
-generally not painful
-a “click” may be palpated during reduction
What are the radiograph options for assessing hip dysplasia?
-VD/OFA view
-VD with distraction/PENN-HIP view
What are the characteristics of OFA views for hip dysplasia?
-VD extended view
-2 year minimum age for final grading
-assessed by 3 radiologists
-hips graded as excellent, good, fair, borderline or mildly, moderately, or severely dysplastic
What are the characteristics of distraction index/PENN-HIP?
-quantifies hip laxity
-diagnostic at earlier ages
-special training required
-radiographs taken with dog under anesthesia or heavy sedation
-involves hip compression and distraction views
How is distraction index calculated?
by taking the distance from the center of the acetabulum to the center of the femoral head and dividing it by the radius of the femoral head
What are the medical management options for hip dysplasia?
-slow rate of growth by restricting energy and calcium in diet
-NSAIDs for pain management
-weight loss
-exercise modification
-adequan
Which surgical options are considered in young animals with hip dysplasia?
-pubic symphysiodesis
-double or triple pelvic osteotomy
Which surgical options are considered salvage procedures in animals with hip dysplasia?
-femoral head and neck ostectomy/excision
-total hip replacement
How does the animal’s age affect the approach to hip dysplasia treatment?
-in young animals, it is ideal to attempt surgery first and then medically manage the patient
-in older animals, medical management is attempted before surgical intervention
What are the characteristics of a juvenile pubic symphysiodesis?
-performed between 16 and 18 weeks of age
-pubic symphysis is surgically damaged so that it fuses and alters pelvic growth
-altered growth includes increased flare of the acetabulum and ilium over the femoral head to provide additional dorsal coverage
-puppies are often clinically normal
-surgical trauma is minimal
What are the characteristics of triple pelvic osteotomy?
-performed in dogs under 1 year old with minimal OA
-best when performed in patients with subluxation of the hip joint, no/minimal radiographic signs, but presence of clinical signs
-3 cuts provide a free-floating acetabulum that can be rotated to provide better femoral head coverage
What is the aftercare following a triple pelvic osteotomy?
-towel support for 2 weeks
-leash walks only for 4-6 weeks until radiographic evidence of healing is present
What are potential complications of a triple pelvic osteotomy?
-implant loosening
-sciatic nerve paresis
-continued subluxation
-stranguria; painful/difficult urination
What is the prognosis for patients that undergo triple pelvic osteotomy?
-typically see clinical improvement within 6 weeks
-OA progresses but not as severely in patients that do not undergo surgery
-must maintain appropriate weight and activity level
-other side may need surgery; typically spaced 4 weeks but can be done together if the window of opportunity requires it
What are the characteristics of femoral head and neck excision?
-can provide reasonable pain control if patients are critically evaluated
-provides the most benefit in dogs with severe lameness and pain on hip manipulation
-post-op pain control and rehab are essential to improve patient comfort
Why is it essential to have to appropriate cutting angle when performing a femoral head and neck excision?
if any of the femoral neck remains, it can catch on the acetabulum and cause pain
What is the post-op care for an FHO procedure?
-analgesic medication
-passive range of motion
-heat and cold therapy
-early active motion
-client involvement if owners can handle it
What is the prognosis for an animal that undergoes an FHO?
-generally less painful
-may be weaker, tire easier, and exhibit residual lameness
-success depends on surgery and rehab
Which clinical signs of hip dysplasia are associated with OA and seen in older dogs?
-lameness/difficulty with stairs and jumping
-crepitus and pain with hip movement
-muscle atrophy
-decreased ROM
What changes occur to the bone in hip dysplasia?
-eburnation/full thickness wearing of the cartilage
-flattening of the femoral head
-osteophyte formation and thickening of femoral neck
What are the medical treatment options for patients diagnosed later in life with hip dysplasia?
-NSAIDs
-weight loss
-exercise modification
-adequan
-alt. treatments like acupuncture, shock wave therapy, and laser
What are the characteristics of total hip replacement?
-effective in providing pain control
-costly
-can provide large dogs better function
-CANNOT be performed if FHO fails
-requires significant aftercare
-complications include infection; can be serious
-early overuse of limb can cause implant to loosen
what are the components of a hip prosthesis?
-polyethylene socket
-stainless steel femoral head
-stainless steel femoral stem
What is legg-calve-perthes disease?
avascular necrosis of the femoral head
Which breeds have a predilection for legg-calve-perthes disease?
-wire-haired fox terrier
-cairn terrier
-mini pinscher
-mini poodle
-bichon frise
-toy poodle
What is the signalment/presentation of legg-calve-perthes disease?
-no gender preference
-generally unilateral
-age range for diagnosis is 3 to 13 months
What are the clinical signs of legg-calve-perthes disease?
-pain
-decreased/no weight bearing
-inability to jump
-sitting improperly
What is the pathophysiology of legg-calve-perthes disease?
-loss of blood supply to dorsal area of proximal femoral epiphysis leaves area of subchondral bone without blood supply
-tissue becomes necrotic
-bone collapses into the defect and becomes condensed due to weightbearing forces
What are the radiographic changes seen in legg-calve-perthes disease?
-flattened femoral head
-lucent areas
What are the characteristics of LCPD treatment?
-perform FHO procedure
-begin physical rehab immediately after surgery
-perform ROM exercises, strengthening, and functional training
