Legg-Calvé-Perthes disease is a rare disease of
the hip that afflicts approximately 1 in 1200 children. Of those
children, only about one in four are girls. About 5% of all
diagnosed develop the disease in both hips (bilaterally). Most
of these children are very active and often very athletic. The
age of diagnosis is usually between 2 and 12 years old, with the
average age of 6. Legg-Calve'-Perthes children tend to be of
shorter stature due to delayed bone age.
Legg-Calvé-Perthes
disease (LCPD) is a form of osteonecrosis of the hip that is found only
in children. It is known by a few other names such as ischemic necrosis
of the hip, coxa plana, osteochondritis and avascular necrosis of the
femoral head. Most commonly it is called Legg-Perthes disease, LCPD, or
Perthes.
LCPD
is of unknown origin. It is known that bone death occurs in the ball of
the hip due to an interruption in blood flow. As bone death occurs, the
ball develops a fracture of the supporting bone. This fracture signals
the beginning of bone reabsorption by the body. As bone is slowly
absorbed, it is replaced by new tissue and bone.
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Initial Phase |
Reabsorption Phase |
Reossification Phase/Healed |
Four Stages of LCPD
- Femoral head
becomes more dense with possible fracture of supporting bone;
- Fragmentation
and reabsorption of bone;
- Reossification when new bone has regrown; and
- Healing, when
new bone reshapes.
Phase I takes
about 6-2 months, Phase 2 takes one year or more, and Phase 3 and 4 may
go on for many years.
The first symptoms
characterized in LCPD are usually a limp and perhaps pain in the hip,
groin, or knee (known as a referred pain). Often you will first notice
limping during your child's active play. They usually cannot tell you an
instance when they hurt themselves. They may not be able to tell you
exactly where they hurt, especially if the pain is referred toward the
knee area. They may not even experience much pain. Other cases may not
be diagnosed until some precipitating event (fall, twisting injury)
leads to an x-ray that uncovers the previously undiagnosed
Legg-Calve'-Perthes disease.
Non-Surgical Treatment
Non-surgical treatments come in varying forms. Crutches are used for
non-weight bearing treatment for pain. Casts, traction, and braces help
return range of motion and mobility. Range of motion exercises may be
given to you by your physical therapist to do with your child in the
home.
Surgical Treatment
Tenotomy
A "Tenotomy" is a surgery that is performed to release an
atrophied muscle that has shortened due to limping. Once released, a
cast is applied allowing the muscle to regrow to a more natural length.
Cast time is about six to eight weeks.
Osteotomy
There are different types of "osteotomies" (cutting the bone to
reposition it) and, depending on the need they are performed at
different stages of the disease. At times with the softening of the
ball, there is the possibility of the ball slipping out of the socket.
To protect it, a femoral varus osteotomy, with or without rotation
partially redirects the ball into the socket. Another approach
to surgically treating Legg-Calve'- Perthes is to do an osteotomy above
the hip socket. This allows the surgeon to reposition the hip socket in
such a way that the femoral head will have less tendency to become
deformed. The shelf arthroplasty gives added coverage of the ball from
the top lip of the socket. Both the innominate and the shelf
arthroplasty help in reshaping.
To learn more contact:
The
National Osteonecrosis Foundation
Johns Hopkins University
School of Medicine, Suite 201
Good Samaritan Professional Building
5601 Loch Raven Boulevard
Baltimore, MD 21239
1-410-532-5985
www.nonf.org
