Legg-Calve Perthes disease is a condition in children in which the ball shaped head of the thigh bone loses its blood supply. Without blood, the bone tissue dies and the bone collapses. As the bone collapses, the head of the thigh bone becomes less rounded, changing the movement and stability of the hip. This causes stiffness, inflammation and pain to occur.
Often, the first noticeable sign of the condition is a child that begins to limp. This limp can occur with or without pain and often has no incident of a fall or trauma to tie to it. Pain will typically be located in the hip, knee or groin. This pain will typically increase with activity and calm with rest.
Although any child can develop Legg-Calve Perthes, it typically occurs in active children between the ages of 4 to 8 years old. Research documents that boys are four times more likely to get the diagnosis than girls.
As the condition runs its course, the body begins to absorb, or “clean up” the dead bone cells and replace them with new, healthier bone cells. It is during this time that treatment by a physician and/or physical therapist becomes vital.
Early diagnosis and treatment allow as much time as possible for the bone to remodel itself back into a round shape.
Without proper or timely treatment, the condition becomes more serious and the bone is more likely to heal in an improper position or shape. Studies indicate that if the ball does not reshape well, or fit well into its socket the child is at a high risk of developing degenerative arthritis at a very early age.
In contrast, with proper and timely treatment arthritis is typically not a concern later in life.
Treatment goals should include: controlling pain, maintaining hip range of motion, increasing hip strength and preventing any additional hip deformity as the bone reshapes. This can typically be achieved through physical therapy treatment, limited activity and limited weight bearing.
Occasionally, surgery or bracing will also need to be implemented to resolve the condition. Children who are older than six or who have more severe cases of Perthes disease are more likely to benefit from surgery in addition to physical therapy. The goal of surgery is to prevent the dislocation or collapse of the hip.
The majority of children treated for Legg Calve Perthes have corrections that enable them to walk, grow and live active lives. Diagnosing and treating early in its development greatly increases the likelihood of a successful outcome.
Hip pain in children is always a cause for concern and should be immediately assessed by a physician to rule out potentially serious conditions such as this one. Any child who has been treated for a hip disorder should be followed periodically by his or her orthopedist until skeletal maturity is achieved. 
QUICK TIPS:
Signs and Symptoms:- Walking with a limp
- Complaints of pain in the hip, knee or groin
- Pain that aggravates with activity
- Pain that calms with rest
- Boys are 4 to 5 times more likely to be affected
- More common in children exposed to second hand smoke
- Affected children are typically:
o Between ages 4 -8
o Very physically active
o Smaller for their age
References:
1.www.childrenshospital.org
2. Kim H. Legg Calve Perthes and Slipped Capital Femoral Epiphysis: Major Developmental Causes of Femoroacetabular Impingement. J Am Acad Orthop Surg. 2013. 21: 559-563.
3. Perry et al. Abnormalities of Vascular Structure and function in Children with Perthes Disease. Pediatrics. 2012. 130:126-131.
