What Is a Hip Joint?

The hip joint consists of a ball (femoral head) and a socket (acetabulum) where the ball of the thighbone fits into the hip socket. 

What Is Hip Dysplasia?

The term “Hip dysplasia” represents a wide spectrum of conditions ranging from complete dislocation of the ball from the socket to a shallow socket in which the ball is not deeply seated. Hip dysplasia can be apparent at birth by clinical examination in some patients. It may not be detected by clinical examination in others, in which case, a hip ultrasound or x-ray is required to make the diagnosis.

What Is Perthes?

Legg-Perthes, or Legg-Calvé-Perthes disease as it is also known, is a condition where blood flow to the ball of the hip joint stops. We don’t know why the blood flow stops so the cause of Perthes is unknown.  The stoppage of blood flow produces bone damage.  A healing process takes place for two or three years. Depending of the age at onset of Perthes and how much of the ball is involved, the outcome varies.  In general, it is better to be younger than age 6 when Perthes occurs.  Read more about Perthes and about the International Perthes Study Group

Hip Disorders and TSRHC

Hip disorders can affect one or both hips and are sometimes apparent at birth. Hip Dysplasia and Legg-Perthes are just a few of the many conditions that affect a child's hip joint. Texas Scottish Rite Hospital for Children treats thousands of patients with hip disorders every year.  Our physicians in the Center for Excellence in Hip Disorders are clinical experts and research leaders in pediatric hip disorders.  Some of the hip conditions treated and researched at TSRHC include:


Our Center for Excellence in Hip Disorders is conducting groundbreaking research to find the causes of and best treatments for these and other pediatric orthopedic conditions.

Areas of Research on Hip Dysplasia

1.  Role of pre-operative traction on the outcome of hip dislocation in infants
2.  Long-term outcome of hip dyplasia in infants
3.  Best way to treat ultrasonic hip dysplasia in infants
4.  Gait and functional outcomes after periacetabular (Ganz) osteotomy for hip dysplasia in teenagers and adolescents

Areas of Research on Perthes disease

1.  Assessing the role of perfusion MRI in predicting the future outcomes of Perthes disease
2.  Comparing nonoperative vs operative treatment for Perthes in patients between age 6-8
3.  Comparing short-term vs longer-term non-weight bearing after surgical treatment in Perthes patients between age 8-11
4.  Long term follow up study of patients with Perthes disease treated with surgery



The cause of many hip disorders is unknown.

For hip dysplasia, there may be a family history of hip dislocation or early arthritis. Some patients have ligamentous laxity (loose jointed). Some of the risk factors for hip dysplasia or DDH include breech position in the womb, first born female, low amniotic fluid during pregnancy, and family history.

For Perthes disease, the cause is unknown. There are other childhood conditions that can mimic Perthes disease and these must be ruled out before making the diagnosis of Perthes. These included traumatic hip injury, steroid-induced osteonecrosis, metabolic disorders, endocrine disorders, infection, and inflammatory conditions.

Physicians often use X-rays or simple diagnostic tests, such as an ultrasound, to evaluate hip disorders.

A complete medical history from the patient and parents, as well as a physical examination, will assist in the diagnosis.

For hip dysplasia or DDH in newborn babies and infants, a hip ultrasound is generally performed. For Perthes disease, hip x-rays are required to confirm the diagnosis. In some patients, advanced imaging such as perfusion MRI is helpful to assess how much of the ball part of the hip joint is involved with the disease.

Treatments for hip disorders are as varied as the conditions that affect the hip and the age of the patient.

TSRHC’s goal is always to improve movement, reduce pain and prevent complications later in life.

For hip dysplasia, the goal of treatment is to reduce the ball into the hip socket gently and safely to restore the normal hip anatomy. For Perthes disease, the goal of treatment is to decrease pain, increase motion, and to prevent the deformation or flattening of the ball part of the hip joint.