What is Legg calve perthes disease?
It is a degenerative disorder that affects the hip joint. It
occurs when there is an insufficiency in the volume of
blood reaching the ball of the thighbone, causing
death of the bone.
the condition is also known as Ischemic Necrosis of
the Hip or Avascular Necrosis of the Hip.
Legg-Calvé-Perthes (LCPD) disease is a childhood hip
disorder that results in infarction of the bony epiphysis
of the femoral head. LCPD represents idiopathic
avascular necrosis of the femoral head.
The disease is bilateral in 10-20% of patients
Children aged 4-8 years
A family history is present in 6% of patients
In adults, the corresponding condition is termed
Male sex (3to 5 times more common).
Common in low socioeconomic group.
Low birth weight babies.
Presence of an inguinal hernia and
Genitourinary tract anomalies.
Legg calve perthes disease Symptoms
Patients usually limp while walking
Constant pain in groin or thigh
Limited range of movement
Hip stiffness, which limits motion in the hip
Reduction of muscles in the upper thigh
Shortening of the leg or unequal length of legs
Several staging schema are used to determine severity
of disease and prognosis; these include the Catterall,
Salter-Thomson, and Herring systems.
The Catterall classification is based on radiographic
appearances and specifies 4 groups during the period
of greatest bone loss.
Catterall staging is as follows:
Stage I — Histologic and clinical diagnosis without
Stage II — Sclerosis with or without cystic changes
with preservation of the contour and surface of
Stage III — Loss of structural integrity of the femoral
Stage IV — Loss of structural integrity of the
acetabulum in addition
Same disease but different names (synonyms)
Avascular necrosis of the femoral head
IMAGING OF PERTHES DISEASE
Early radiographic signs of LCPD
Small femoral epiphysis (96%)
Sclerosis of the femoral head with sequestration and
Slight widening of the joint space caused by
thickening of the cartilage, failure of epiphyseal
growth, the presence of joint fluid, or joint laxity
the flattened appearance on the affected side, compared
to the smooth curve of the femoral head on the normal
Late signs of LCPD on radiographs
Delayed osseous maturation of a mild degree, a
radiolucent crescent line representing a subchondral
Femoral head fragmentation and femoral neck cysts
from intramedullary hemorrhage or loose bodies, and
Coxa magna, or remodeling of the femoral head, which becomes wider
and flatter, similar in appearance to a mushroom
Early signs of LCPD on CT scans include the following:
Curvilinear zones of sclerosis
Subtle changes in bone trabecular pattern
Late signs of the disease on CT scans include :
Central or peripheral areas of decreased attenuation
Coronal reconstructions can show subchondral
fractures, or collapse of the articular surface.
Legg-Calvé-Perthes disease. Axial nonenhanced CT scan through the
hip joints shows the loss of structural integrity of the right femoral
Legg-Calvé-Perthes disease. Nonenhanced axial CT section through
the hip joints obtained at a different level in the same patient as in the
previous images. Once again, the scan shows the loss of structural
integrity of the right femoral head. Note the acetabular subchondral
Legg-Calvé-Perthes disease. Coronal reconstruction shows
flattening, sclerosis, and early fragmentation of the right
Magnetic Resonance Imaging
Early in the course of LCPD, irregular foci of low signal
intensity or linear segments replace the normal high
signal intensity of bone marrow in the femoral
epiphysis on T1- and T2-weighted images.
Other findings include an intra-articular effusion and
a small, laterally displaced ossification nucleus, and
femoral head deformity.
Legg-Calvé-Perthes disease. Coronal T2-weighted MRIs show irregularity and
flattening of cortical margins of the left femoral epiphysis. Also note a mild
Legg-Calvé-Perthes disease. Coronal T1-weighted MRIs show the loss of
normal high signal intensity in the left femoral epiphysis, which now
has low signal intensity.
Legg-Calvé-Perthes disease. Axial T1-weighted MRIs through the femoral
heads show low signal intensity in the left femoral head.
Ultrasonography is useful in establishing the diagnosis
of transient synovitis of the hip and the onset of LCPD.
Assessment of epiphyseal cortex.
Articular cartilage assesment.
Normal anatomy of the anterior hip joint capsule. fce = femoral capital
epiphysis; fm = femoral metaphysis; between cursors = both layers of joint
capsule (hyperechoeic to muscle); I = iliopsoas muscle; small arrows =
echogenic interface between joint capsule layers.
Normal right hip compared to the left hip with an effusion. Hyperaemia of the
soft tissues is evident on the left side. The machine settings are kept the same
Transverse image of both hips at the level of the neck
of femur. Fluid distends the joint capsule on the left
side (as marked by calipers).
Perthes disease with joint effusion but normal
Perthes disease in a 4 year old boy with fragmentation
of the femur epiphysis
Perthes disease with irregular flattened epiphysis and
Technetium-99m diphosphonate uptake depends on
the stage of the disease, but it does play a role in the
diagnosis. Characteristic features include a photopenic
void in proximal femoral epiphyses as compared with
the contralateral side.
Legg-Calvé-Perthes disease. Magnified pinhole views from a bone scan show
decreased accumulation of radiopharmaceutical in the lateral aspect of the left
femoral head (arrow), caused by disruption of the blood supply to the femoral
head. The normal right femoral head is shown for comparison.
Legg calve perthes disease Differential Diagnosis
The differential diagnosis of LCPD includes ruling out
the possibility of the symptoms being caused by other
disorders, such as:
Juvenile idiopathic arthritis
Sickle cell disease
Transient synovitis of the hip