Perthes Disease Flashcards
What age generally should you suspect Perthes Disease in?
Disease generally of mid childhood
What is the pathophysiology of Perthes disease?
The blood supply to the head of the femur (going over the physis) is disrupted, and if the blood supply remains compromised, avascular necrosis occurs, and the ball and socket joint begins to collapse. While the disease is running its course, forces of the hip can cause a lot of deformation.
Tends to be transient and occur over the course of a year or so. When the blood supply starts to return/grow back to the head of the femur the bone will regrow and re-harden.
The shape it rehardens into can be an issue— It can be flat or the body might not have enough time to reshape it.
What is Legg-Calve-Perthes disease?
Osteochondrosis (aseptic ischemic necrosis) that affects the proximal femoral epiphysis. Manifests as idiopathic avascular necrosis of the femoral head
Does Perthes disease have a better prognosis in younger kids?
Yes.
—Older kids dont have as much time or plasticity to reshape a femur head that has hardened in an imperfect position
—Younger kids also have a thicker cartilage mantle vs ossified bone, therefore, in the event of avascular necrosis of the bone, they have a greater backup of cartilage mantle to sustain the forces of the hip
What causes Perthes disease?
Clotting abnormalities:
—50% incidence of thrombophilia
—The reason it happens is kind of unknown
Environmental factors:
—Smoking household is more likely to get it than a non smoking household
How does Perthes disease present?
LIMP— most frequent presenting complaint
PAIN (groin / thigh)
—second most frequent
—Can initially be painless and then develop pain
Child is usually small for age
Child is hyperactive - 33% with ADHD
What limitations are seen on exam for Perthes disease?
Limited abduction and internal rotation is the most notable limitation of motion
Trendelenburg gait with stiffness
—may disguise limp if rested
What’s on your differential for Perthes disease that you need to rule out?
Known causes of osteonecrosis: —Sickle cell disease —Thalassemia —Leukemia and Lymphoma —ITP —HemOphelia
Hypothyroidism
Skeletal dysplasia
—Multiple epiphyseal dysplasia
—Spondyloepiphyseal dysplasia
—these look exactly like Perthes disease, except they will be BL. Perthes is usually Unilateral (10% BL)
Is Perthes disease usually unilateral or bilateral?
Usually unilateral
10% can be BL
What is the clinical course/stages of Perthes disease?
Stages:
1. Initial— 6-12 months
—where the bone is starting to get necrotic
—after this period they start resorbing it and thats usually when sx present
- Fragmentation phase
- Reossification
- Remodeling
Radiographic findings of Perthes disease?
Initially minimal radiographic signs and then sclerosis
What is the containment concept for perthes disease?
“Containment” of the fragmented head in the acetabulum.
Concept is to use the unaffected acetabulum to mold the soft femoral head so that it keeps it round ish while the process is running its course and the femoral head “re hardens”
What is non surgical treatment for Perthes Dz?
Casting to rest hip and restore ROM
— abduct and bring the exposed edge of the femoral head under the acetabulum
—Not that effective and has fallen out of favor: used for short term in anticipation of surgery or restore motion
“Containment” via Abduction Bracing
—Petrie casts that have a bar in the middle holding the legs wide apart
What is the surgical treatment for Perthes dz
Surgical containment
—Augmenting the acetabulum cup to tilt it out and make sure the fit is compliant
—Head of femur is held in place with screws and plates to hold the alignment> can be removed after the healing phase has taken place
You cant predict in an individual if the surgery will benefit them
Prognosis for kids <6yo
Kids <6yo (definitely kids <4yo) do very well with symptomatic treatment
