Perthes disease is a childhood hip disorder initiated by a disruption of blood flow to the head of the femur. Due to the lack of blood flow, the bone dies (osteonecrosis or avascular necrosis) and stops growing. Over time, healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head. The bone loss leads to some degree of collapse and deformity of the femoral head and sometimes secondary changes to the shape of the hip socket. It is also referred to as idiopathic avascular osteonecrosis of the capital femoral epiphysis of the femoral head since the cause of the interruption of the blood supply of the head of the femur in the hip joint is unknown.
Classification or Stages of Perthes Disease
There are four stages in Perthes disease
- Initial/necrosis – In this stage of the disease, the blood supply to the femoral head is disrupted and bone cells die. The area becomes intensely inflamed and irritated and your child may begin to show signs of the disease, such as a limp or different way of walking. This initial stage may last for several months.
- Fragmentation – Over a period of 1 to 2 years, the body removes the dead bone and quickly replaces it with an initial, softer bone (“woven bone”). It is during this phase that the bone is in a weaker state and the head of the femur is more likely to break apart and collapse.
- Reossification – New, stronger bone develops and begins to take shape in the head of the femur. The ossification stage is often the longest stage of the disease and can last a few years.
- Healed – In this stage, the bone regrowth is complete and the femoral head has reached its final shape. How close the shape is to round will depend on several factors, including the extent of damage that took place during the fragmentation phase, as well as the child’s age at the onset of disease, which affects the potential for bone regrowth
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|Stages of Legg-Calves-Perthes (Waldenström)|
|Initial||• Infarction produces a smaller, sclerotic epiphysis with medial joint space widening||• Radiographs may remain occult for 3 to 6 m|
|Fragmentation||• Begins with presence of subchondral lucent line (present sign) • Femoral head appears to fragment or dissolve • Result of a revascularization process with bone resorption producing collapse with subsequent patchy density and lucencies|| • Hip-related symptoms are most prevalent
• Lateral pillar classification based on this stage • Can last from 6m to 2y
|Reossification||• Ossific nucleus undergoes reossification with new bone appearing as the necrotic bone is resorbed||• May last up to 18m|
|Healing or remodeling||• Femoral head remodels until skeletal maturity||• Begins once ossific nucleus is completely reossified; trabecular patterns returns|
|Lateral Pillar (Herring) Classification|
|Group A||• lateral pillar maintains full height with no density changes identified||• consistently good outcome|
|Group B||• maintains >50% height||• poor outcome in patients with bone age > 6 years|
|B/C Border||• lateral pillar is narrowed (2-3mm) or poorly ossified with approximately 50% height||• recently added to increase consistency & prognosis of classification|
|Group C||• less than 50% of lateral pillar height is maintained||• poor outcomes in all patient|
|Group I||• involvement of the anterior epiphysis only|
|Group II||• involvement of the anterior epiphysis with a central sequestrum|
|Group III||• only a small part of the epiphysis is not involved|
|Group IV||• total head involvement|
Causes & Risk factors of Perthes Disease
- Age – Although Legg-Calve-Perthes disease can affect children of nearly any age, it most commonly occurs between ages 4 and 8.
- Your child’s sex – Legg-Calve-Perthes is up to five times more common in boys than in girls.
- Race – White children are more likely to develop the disorder than are black children.
- Family history – In a small number of cases, Legg-Calve-Perthes appears to run in families.
Symptoms of Perthes Disease
- Pain in the hip or groin, or in other parts of the leg, such as the thigh or knee (called “referred pain.”).
- Pain that worsens with activity and is relieved with rest.
- Painful muscle spasms that may be caused by irritation around the hip.
- Pain in the knee, thigh or groin
- Stiffness in the hip
- Limited range of motion in the hip
- Upper thigh muscles get smaller
- Legs appear to be different lengths
Diagnosis of Perthes Disease
- X-rays – Initial X-rays may look normal because it can take one to two months after symptoms begin for the damage associated with Legg-Calve-Perthes disease to become evident on X-rays. Your doctor will likely recommend several X-rays over time, to track the progression of the disease.
- Magnetic resonance imaging (MRI) – This technology uses radio waves and a strong magnetic field to produce very detailed images of bone and soft tissue inside the body. MRIs often can visualize bone damage caused by Legg-Calve-Perthes disease more clearly than X-rays can.
- Bone scan – In this test, a small amount of radioactive material is injected into a vein. The material is attracted to areas where bone is rapidly breaking down and rebuilding itself, so these areas show up on the resulting scan images.
Treatment of Perthes Disease
If your child is younger than 6 or 7, your doctor may just recommend observation and symptomatic treatment with stretching, limited running and jumping, and medications as needed. Other nonsurgical treatments include:
- Crutches – In some cases, your child may need to avoid bearing weight on the affected hip. Using crutches can help protect the joint.
- Traction – If your child is in severe pain, a period of bed rest and traction may help. Traction involves a steady and gentle pulling force on your child’s leg.
- Casts – To keep the femoral head deep within its socket, your doctor may recommend a special type of leg cast that keeps both legs spread widely apart for four to six weeks. After this, a night-time brace is sometimes used to maintain hip flexibility.
- Hip rotation – With the child on his or her back and legs extended out straight, parents should roll the entire leg inward and outward.
- Limiting activity – Avoiding high impact activities, such as running and jumping, will help relieve pain and protect the femoral head. Your doctor may also recommend crutches or a walker to prevent your child from putting too much weight on the joint.
- Physical therapy exercises – Hip stiffness is common in children with Perthes disease and physical therapy exercises are recommended to help restore hip joint range of motion. These exercises often focus on hip abduction and internal rotation. Parents or other caregivers are often needed to help the child complete the exercises.
- Casting and bracing – If the range of motion becomes limited or if x-rays or other image scans indicate that a deformity is developing, a cast or brace may be used to keep the head of the femur in its normal position within the acetabulum.
- Hip abduction – The child lies on his or her back, keeping knees bent and feet flat. He or she will push the knees out and then squeeze the knees together. Parents should place their hands on the child’s knees to assist with reaching a greater range of motion.
Medication of Perthes Disease
- Anti-inflammatory medications – Painful symptoms are caused by inflammation of the hip joint. Anti-inflammatory medicines, such as ibuprofen, are used to reduce inflammation, and your doctor may recommend them for several months.
- Oral corticosteroids – or those that are injected directly into the hip joint
- The joint aspiration to temporarily relieve pressure, which is sometimes followed by a corticosteroid injection
- Antibiotics – In case an infection the physician will prescribe appropriate antibiotics to treat the infection.
- Fish-oil capsules – A British study found that 86 percent of people with arthritis who took cod liver oil had far fewer enzymes that cause cartilage damage compared to those who got a placebo. Plus, they had far fewer pain-causing enzymes. Cod liver oil is a fish oil, so your basic fish-oil supplement will do fine.
- Vitamin E containing pure alpha-tocopherols – A German study found taking 1,500 IU of vitamin E every day reduced pain and morning stiffness and improved grip strength in people with rheumatoid arthritis as well as prescription medication.
- Glucosamine/chondroitin – This combination supplement may provide long-term pain relief and slow the degeneration of cartilage. It has also been found that glucosamine and chondroitin can actually repair damaged cartilage. After about a month you should be getting enough pain relief from the glucosamine to stop taking ibuprofen.
- Neuropathic pain – To control the neuropathic pain use pregabalin or gabapentin in the supervision of doctor or pharmacist.
- Calcium & Vitamin D3– to improve bones health
Surgery of Perthes Disease
Most of the orthopedic treatments for Legg-Calve-Perthes disease are aimed at improving the shape of the hip joint to prevent arthritis later in life.
- Contracture release – Children who have Legg-Calve-Perthes often prefer to hold their leg across the body. This tends to shorten nearby muscles and tendons, which may cause the hip to pull inward (contracture). Surgery to lengthen these tissues may help restore the hip’s flexibility.
- Joint realignment – For children older than 6 to 8, realignment of the joint has been shown to restore a more normal shape to the hip joint. This involves making surgical cuts in the femur or pelvis to realign the joints. The bones are held in place with a plate while the bone heals.
- Removal of excess bone or loose bodies – In older children with painful, restricted motion, trimming extra bone around the femoral head or repairing damaged cartilage may ease motion and relieve pain. Loose bits of bone or torn flaps of cartilage can be removed.
- Joint replacement – Children who have had Legg-Calve-Perthes sometimes require hip replacement surgery later in life. These surgeries can be complicated because of a higher risk of bone fracture and nerve damage.
Valgus and/or shelf osteotomies
- Lateral extrusion of the capital femoral epiphysis producing a painful hinge effect on the lateral acetabulum during the abduction
- Abduction-extension osteotomy reposition the hinge segment away from the acetabular margin correct shortening from fixed adduction improve abductor mechanism by improving abductor muscle contractile length
- Shelf or Chiari osteotomies are also considered when the femoral head is no longer containable.
- Emerging treatment modality for mechanical abnormalities in the setting of healed LCPD femoral acetabular impingement
- controversial indications and outcomes
- distraction via external fixation
Lifestyle and Home Remedies of Perthes Disease
Home care measures to reduce pain and prevent damage include
- Activity modification. Your child should avoid high-impact activities, such as running or jumping, because they can increase the amount of damage to the weakened bone and worsen symptoms.
- Pain medication. Over-the-counter medicines such as acetaminophen (Tylenol, others) can help relieve pain. Don’t give your child aspirin as it’s been linked to a rare, but serious, a condition called Reye’s syndrome.
- Heat or cold. Hot packs or ice may help relieve hip pain associated with Legg-Calve-Perthes disease. Using heat before stretching exercises can help loosen tight muscles.
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