Perthes disease is a rare childhood condition that affects the hip joint of a child. It happens when the blood supply to the ball of the femur is for the nonce stopped. With inadequate blood supply to the bone, the bone cells die, a process called avascular necrosis start. 

Although the term “disease” is still used, Perthes is really a complex process of stages that can last for several years; we can also say that it is a chronic disease. As the condition progresses, the bone of the head of the femur gradually begins to disintegrate. With time, the blood supply to the ball of the femur begins again and the bone starts to grow back leading to tremendous hip joint pain. 

Treatment for Perthes disease emphasises on assisting the bone in growing back into its rounded shape that still fits back into the socket of the hip joint. This will help the hip joint slide normally and avert hip problems in adulthood. 

The long-term prospect for children with Perthes is good in most of the cases. After 18 to 24 months of treatment, most children retaliate to daily activities without major obstacles. 

Perthes disease — also called Legg-Calve-Perthes, named for the three separate doctors who first elucidated the condition — typically arises in children who are between the age group of 4 to 10 years old. It is five times more ordinary in boys than in girls, although, it is likely to cause more immense harm to the bone in girls. In 10% to 15% of all conditions, both the hips are affected. 

There are four stages in Perthes disease: 

  • Initial/necrosis: In the beginning stage of the disease, the blood supply to the femoral head is stopped and bone cells die. The area becomes vigorously itchy and aggravate and your child may start to show signs of the disease, such as a stagger or different way of walking or leg pain. This initial stage of the disease may last for several months. 
  • Fragmentation: Over duration of 1 to 2 years, the body relocates the dead bone beneath the articular cartilage and swiftly substitutes it with an initial, softer bone (“woven bone”). It is during this phase that the bone is in a delicate state and the head of the femur is more likely to disintegrate into a flatter position. 
  • Reossification: New, impregnable bone develops and begins to take shape in the head of the femur. The reossification stage is often the longest stage of the disease and can last for a number of years. 
  • Healed: In this stage, the bone development is complete and the femoral head has reached its final shape. 

Causes 

The cause of Perthes disease is not still recognized. Some recent studies stipulate that there may be a genetic link to the development of Perthes, but more research needs to be carried out. 

Symptoms 

One of the primary indications of calve Perthes is the change in the way a child walks and runs. This is often most evident during sports activities. Your child may stagger, have finite motion, or develop an anomalous running style, all due to irritability/hip joint pain. Other common symptoms include: 

  • Pain in the hip part or in other parts of the leg, such as the thigh or knee (called “referred pain.”). 
  • Hip joint pain that worsens with motion and is palliated with rest. 
  • Painful muscle contraction that may be caused by irritation around the hip area. 

Your doctor will consider multiple factors when instigating a treatment plan for your child, including: 

  • Your child’s age: Younger children (age 6 and below) have a greater possibility for growing new, healthy bone. 
  • The degree of damage to the femoral head: If more than 50% of the femoral head has been damaged by necrosis, the possibility for regrowth without deformity is less. 
  • The stage of disease at the time your child is diagnosed: How long your child has been suffering from the disease affects which treatment options your doctor will recommend. 

Treatment 

There are two types of treatments both nonsurgical and surgical. 

Nonsurgical treatment 

Anti-inflammatory medications: Painful symptoms are generated by inflammation of the hip joint. Anti-inflammatory medicines, such as ibuprofen, are used to reduce inflammation (swelling and itching), and your doctor may prescribe them for some months. As a child progresses through the stages of the disease, the doctor might change the dosage or even discontinue the medication. 

Physical therapy exercises: Hip tension is common in children with Perthes disease and physical therapy exercises are advised to help redevelop hip joint range of motion. These exercises often focus on hip acquirement and internal rotation. Parents or other caretakers are often required to help the child complete the exercises. 

Surgical treatment 

An operation can be considered in some cases, particularly in older children or those more divergently affected. Surgery can help to keep the femoral head that is a ball of the ball and socket in the right position while it heals with time. Surgery can also help in improving the shape and function of the femoral head if it has not healed well within a period of time.