Developmental Dysplasia of the Hip (DDH)

What is developmental dysplasia of the hip (DDH)?

Developmental dysplasia of the hip (DDH), also called hip dysplasia, can be present at birth or develop as your child grows. It describes a wide range of problems, such as a misshapen ball or socket, or a loose hip joint. DDH occurs in one in every 1,000 births. It can run in families or can be caused by something in the baby’s environment. It may happen as a result of the baby's response to the mother's hormones during pregnancy. It is more common in girls, and more likely to occur in the left hip.

There are several risk factors linked to DDH, including:

  • Family history of DDH
  • Very flexible ligaments
  • Position of the baby in the uterus, such as breech position
  • First-born babies (because the uterus is small)
  • Limited space in the uterus
  • Other orthopaedic problems that include metatarsus adductus, clubfoot deformity, congenital conditions and other syndromes

How to spot DDH

With DDH, the hip socket (acetabulum) may be shallow, which allows the ball (femoral head) of the leg bone to slip in and out of the hip socket. The ball may move partially or completely out of the socket. Symptoms can vary by age of the child. 

In babies, infants and toddlers with DDH:

  • One leg may appear shorter than the other
  • The rotation of one hip may be different
  • Folds in the skin of the thigh or buttocks may be uneven
  • Space between the legs may look wider than normal
  • The hip may shift, click or clunk during certain movements, such as diaper changes

Signs of DDH in adolescents, teens and young adults include:

  • Hip pain
  • Clicking sound in the hip joint
  • Catching feeling in the hip joint
  • Too much or too little movement of the hip
  • One leg shorter than the other

How we diagnose DDH

Our team takes a specialized approach to diagnosing DDH complications in children:

  • A complete medical history and physical examination (Your doctor will do a physical exam of your child at birth and during infancy to check for DDH and other hip problems. Signs may not show until later in life.)
  • X-ray
  • Magnetic resonance imaging (MRI)
  • Computed tomography (CT) scan
  • Ultrasound (used in children under six months of age)

How we treat DDH

The goal of treatment is to put the ball back into the hip socket so the hip can develop normally. Some hips do not continue to develop normally and need more treatment.

Treatment for your child is based on:

  • Your child’s age
  • The extent of the DDH
  • Your child’s medical history
  • Your child’s tolerance to medicine, procedures and therapies

Treatment options may include:

  • Pavlik harness: A tool for babies up to 6 months of age. This harness keeps the hip in the right place while allowing the legs to move, and is usually worn for at least six weeks. It’s important for a doctor to monitor the hips as your child grows. The hips may not fully develop, requiring further treatment.
  • Abduction brace: A hard, plastic brace with foam padding that holds the hips more firmly than a Pavlik harness. It’s normally worn for at least three months.
  • Surgery: Allows the doctor to manually put the hip into place. If the other methods are not successful, or if DDH is diagnosed after the age of 6 months, surgery and casting may be needed. 
    • A closed reduction surgery may be necessary to put the hip back into place manually. This procedure is sometimes combined with procedures called an arthrogram and an adductor tenotomy, which are used to help assess the reduction and increase hip stability and flexibility.
    • If the closed reduction surgery is successful in putting the hip back into its proper place, a special cast called a spica cast is used to hold the hip in place.
  • Periacetabular osteotomy (PAO): Children with DDH who have reached or have almost reached their maximum skeletal growth might need a periacetabular osteotomy (PAO) procedure to reduce joint stress and improve hip function. This procedure allows the surgeon to make cuts around the hip socket to move it back into a more normal position. A PAO can also help delay or eliminate the need for total hip replacement later in life. 
  • Physical therapy: Used to make the muscles around the hip stronger and help teach children how to walk again.

Femoroacetabular Impingement (FAI)

What is femoroacetabular impingement (FAI)?

FAI is too much friction between the top of the thigh bone (femoral head) and the outside part of the hip socket (acetabulum). This might damage the hip joint over time.

Some childhood problems can lead to FAI. These include:

  • Legg-Calve-Perthes disease
  • Slipped capital femoral epiphysis (SCFE)

Some doctors believe that heavy physical activities before the body stops growing may lead to FAI. Football and weightlifting are activities that might lead to FAI. FAI can lead to hip labral tears, cartilage damage and degenerative osteoarthritis. It is a common cause of hip pain in adolescents although it rarely occurs in growing children. Many childhood hip conditions like Perthes and slipped capital femoral epiphysis can lead to the development of FAI.

Two major types of FAI

Most people with FAI have both types, including:

  • Cam: This type happens when the top of the thigh bone (femur) has an odd shape. An abnormal bump on the upper femur can cause uneven contact with the hip socket, possibly damaging the cartilage.
  • Pincer: This type happens when the outside part of the hip socket is too deep or goes in the wrong direction. This might cause pinching of the outer part of the cartilage (labrum) with movement
  • Mixed cam-pincer: This type is caused by a combination of excess bone or larger than normal ranges of motion.

How to spot FAI

Signs of FAI can begin in the childhood, but it is much more common in young and middle-aged adults. Pain and limited hip range of motion are the two most common symptoms. The pain is felt when abnormal contact occurs or when tissues become permanently damaged.

The signs may get worse with age and include:

  • Pain in the hip, lower back, groin, thigh or knee (pain rarely goes below the knee)
  • Pain during physical activity, such as walking or running
  • Pain after sitting for a long time
  • Loss of motion in the hip joint
  • Labral tears
  • Cartilage damage
  • Early hip arthritis
  • Hyperlaxity (too much movement in the hip)

The pain tends to occur more with the hip in a flexed and internally rotated position (rolled in). Many patients find that rotating their hips outward helps to relieve some of the pain. Hip flexion and internal rotation are typically limited.

How we diagnose FAI

Our team uses equipment designed to diagnose issues related to FAI in kids and teens:

  • A complete medical history and physical examination
    • Physical examination can show decreased hip flexion and internal rotation. If pain occurs with forced internal rotation of the hip in a flexed position, this is known as a positive impingement test. An exam can also help to differentiate FAI from other common adolescent hip conditions.
  • X-ray
  • Magnetic resonance imaging (MRI)
  • Computed tomography (CT)

How we treat FAI

If FAI is detected and treated early, before irreversible damage occurs, there is hope that degenerative osteoarthritis (bone weakening) may be delayed or even prevented. 

Treatment can include:

  • Activity modification
  • Medications
  • Physical therapy and hip strengthening exercises (hip stretching exercises may not be recommend if they will cause further damage.)
  • Limiting physical activities
  • Surgery:
    • Often other measures do not provide enough relief. Your child’s doctor may recommend surgery to improve the hip's range of motion, and prevent further damage or fix current cartilage and labral damage, if possible. Often torn or worn cartilage cannot be repaired.
    • Surgery can be arthroscopic (small incisions), open, or a combination of the two. The type of surgery depends on the amount of damage to the cartilage.
      • Learn more about hip arthroscopy
      • Other surgical treatments:
        • Surgical dislocation of the femur from the socket (allows the doctor to trim excess bone repair necessary areas with suture anchors)
        • Reverse periacetabular osteotomy (involves a series of cuts around the hipbone socket where the femur connects (acetabulum) and then repositioning the entire socket. This technique is useful in cases where it’s rotated backward and trimming the excess bone might lead to instability.)

Legg-Calvé-Perthes Disease

What is Legg-Calvé-Perthes disease?

In the growing child, the two major components of the hip joint are the ball (femoral head) and the socket (acetabulum). Legg-Calvé-Perthes disease, or Perthes disease, is a childhood hip condition in which the ball-shaped head of the thigh bone (femoral head) loses its blood supply and collapses. When this happens, a part or all of the area involved temporarily dies. It is important to understand that the acetabulum (socket) is not affected or involved in this loss of blood supply. The body will absorb the dead bone cells and replace them with new bone cells. The new bone cells eventually reshape the femoral head of the thigh bone. Legg-Calvé-Perthes disease causes the hip joint to become painful and stiff. It can also leave the femoral head deformed and lead to disability.

The femoral head in the growing child has several distinct zones:

  1. The metaphysis is the spongy bone area in the femoral neck or that portion of bone next to the femoral head.
  2. The physis is the growth center of the femur (thigh bone) and is composed of bone forming cells that enable the bone to grow in length.
  3. The epiphysis is located between the physis and the acetabulum (socket), and it actively contributes to the growth of the femoral head (ball portion). 

Perthes disease goes through four phases:

  • Phase 1: Blood stops reaching the femoral head, and the hip joint becomes inflamed, stiff and painful. Portions of the bone turn into dead tissue. The ball of the thigh bone becomes less round. This phase can last from several months up to one year.
  • Phase 2: The body cleans up the dead bone cells and replaces them with new, healthier bone cells. The femoral head begins to remodel into a round shape again. The joint is still irritated and painful. This phase can last from one to three years.
  • Phase 3: The femoral head continues to model itself back into a round shape with new bone. This phase lasts for one to three years.
  • Phase 4: Normal bone cells replace the new bone cells. This last phase can last a few years to complete the healing process.

It is important to understand that every affected child goes through each phase, from beginning to end. This whole process can extend over many months to years.

What causes Perthes disease?

The cause of Perthes disease is unknown. We do know that it:

  • Is four times more likely in boys than girls
  • Commonly affects firstborn children
  • Is most often seen in the 4 to 8-year age group, but children age 2-years up to teenagers can be affected 
  • Most cases affect only one hip. It can involve both, but does not happen to both at the exact same stage.
  • Has not been proven to be inherited

How to spot Perthes disease

The most common signs include:

  • Walking with a slow limp that occurs at irregular intervals
  • Limited range of motion in the hip
  • Pain in the hip, thigh or knee, though pain is not usually a major factor. Pain often seems more activity related. 

The symptoms may resemble other conditions or medical problems of the hips, so it’s important to talk to your child’s doctor. Due to the slow onset and minimal pain, it may be months before the parents seek help. Often, children will complain of knee pain, when the problem is located in the hip. During the initial examination, the doctor may find a child that limps, has loss of motion around the hip, and in cases of longer duration, evidence of muscle wasting. The child may need to have an arthrogram (dye injected into the hip joint) to determine the shape and status of the femoral head.

How we diagnose Perthes disease

Our team uses a thorough set of assessments to diagnose Perthes disease:

  • A complete medical history and physical examination
  • X-ray
  • Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI)
  • Arthrograms
  • Blood tests
  • Bone scans

How we treat Perthes disease

Our team will work with you to create a treatment plan for Perthes disease based on:

  • Your child's age, overall health and medical history
  • Amount of hip pain or stiffness
  • Degree of femoral head collapse
  • Progression of the condition
  • Your child's tolerance for certain medications, procedures or therapies
  • How the condition is likely to affect your child
  • Your opinion or preference

The goal of treatment is to preserve the roundness of the femoral head and to prevent deformity while the condition runs its course. At first, treatment focuses on regaining hip motion and reducing pain from the tight muscles around the hip and inflammation inside the joint. Maintenance of good hip motion and containment (keeping the ball in the socket) is important. The socket (not involved in Perthes disease) acts as a template to help shape the deformed femoral head during healing.

A long-term study identified four major factors that impact the outcome:

  1. The child's age at onset. This is probably the most important factor influencing the outcome.
    • Children under the age of six often have good long term outcomes regardless of the treatment.
    • Children in the six to eight year old range have the most varied treatment options and outcomes.
    • Children older than eight years old are often recommended to have surgery.
  2. The extent of involvement of the femoral head (the percent losing its blood supply). If the area is small, the outcomes are better.
  3. The ability to keep the femoral head in the acetabulum (ball in the socket) during the disease process (also called containment).
  4. Loss of motion of the hip joint

We don’t have control over the first two factors, so we focus on the last two during management or treatment of the disease. 

Treatment may include:

  • Bed rest and traction
  • Casting or bracing (to hold the femoral head in the hip socket, restrict joint movement and allow the femur to remold itself into a round shape again. A brace maybe used to maintain containment. Plaster casts are often used temporarily while the brace is being manufactured.)
  • Crutches or wheelchair
  • Medications (such as Ibuprofen to help with inflammation)
  • Physical therapy (to keep the hip muscles strong and to promote hip movement)
  • Reduced activity
  • Routine examinations are performed by your doctor to help ensure progress
  • Surgery:
    • Arthroscopic or open surgery (to hold the femoral head in the hip socket)

    Studies show as many as 90% of the patients that are 30 to 40 years after their onset are active and pain free. This means that while most hips will not return to normal shape, the child will enjoy the ability to keep up with their friends as they go through life.

Slipped Capital Femoral Epiphysis (SCFE)

What is slipped capital femoral epiphysis (SCFE)?

In SCFE, the head, or "ball," of the thigh bone (the femoral head) slips off the neck of the thigh bone. This condition causes the hip joint to become painful and stiff. The slipping can happen very quickly (acute or unstable) from an accident or trauma and lead to significant pain and an inability to walk. It is more likely the slipping will occur slowly (stable or chronic), leading to a limp that may vary in severity over time. The foot turns out and the child leans over the affected side when weight is applied to that leg. About a third of the children with a stable or chronic slip complain of knee pain instead of hip pain.

SCFE can cause significant problems for patients in a number of ways. The slipping can result in significant hip deformity leading to joint problems later in life. A more serious concern is tearing of blood vessels that supply nutrition to the portion of the thigh bone that forms the hip joint. The disruption (avascular necrosis or AVN) can lead to significant hip joint deformity and permanent stiffness and pain.

Facts about SCFE:

  • It is the most common hip problem in adolescents, but it is rare. Only between two to 10 people in every 100,000 get SCFE.
  • This slipping can only happen in children who are still growing, but usually occurs as the child is entering puberty. Children ages 11 to 15 are most at risk.
    • Girls are usually affected around the age of 12 and boys impacted around 13.5 years old.
  • It is more common in boys than girls and tends to occur in heavy-set children.
  • It is more common among African-Americans.
  • About one half of cases affect both hips.
  • It can range from mild to severe:
    • Mild: Up to one-third of the femoral head slips off of the thigh bone.
    • Moderate: About one-third to one-half of the femoral head slips off of the thigh bone.
    • Severe: More than one-half of the femoral head slips off of the thigh bone.

The cause of SCFE is unknown. Risk factors include:

  • Bone problems related to kidney disease
  • Chemotherapy
  • Medications (such as steroids)
  • Obesity
  • Radiation treatment
  • Thyroid problems

It is important to understand that SCFE can occur in either hip. If a child has a slip in one hip, there is approximately a 30% chance that the other hip will slip as well.

  • 30% of the time both hips slip at the same time (synchronous slip)
  • 70% of the time one hip will slip and then the other hip will slip within about 18 months (asynchronous slip)

We recommend every child has both hips routinely examined. If any symptoms of hip or knee pain appear, especially when associated with the limp, the child should stop walking and be seen immediately by an orthopaedic surgeon. The best treatment for SCFE is to stop the slip before there is distortion of the hip bone.

How to spot SCFE

The symptoms of SCFE may resemble other conditions or medical problems of the hip. Symptoms of SCFE typically include:

  • Pain in the hip that is aggravated by activity
  • Pain in the groin, thigh or knee area
  • Sudden pain, limp or feeling like the leg is giving way (acute slip)
  • Hip pain and limp that is relieved by rest (chronic slip)
  • Walking with leg turned outward
  • Feeling or hearing a click in the hip

How we diagnose SCFE

  • A complete medical history and physical examination
  • X-ray
  • Magnetic resonance imaging (MRI)

The goal is to diagnose the condition early, to prevent the head of the femur from slipping further off of the thigh bone.

How we treat SCFE

When SCFE is diagnosed, your child should stop standing, walking or bearing weight on the hip. Your child will need crutches or a wheelchair for a while. The goal is to limit the amount of deformity caused by the slipping and not cause any new problems. The problem must be recognized early before any significant slipping occurs and treatment should begin before the deformity happens. 

We will work with you and your child to create a treatment plan based on:

  • Age, overall health and medical history
  • The extent of the condition
  • Your child’s tolerance for medications, procedures or therapies
  • How the condition is likely to affect your child
  • Your opinion or preference

Treatment may include:

  • Surgery
    • Your doctor may use minimally invasive techniques to make small incisions to stabilize the slipping by placing one or two large screws across the unstable growth plate. Most children are able to leave the hospital the same day and will walk with crutches for four weeks. The screws are made of titanium or stainless steel, are completely encased in bone, and are usually left in place throughout life. Children should not be able to feel the screw and your child will be able to resume all activities after it’s healed, including sports. Tell your doctor if pain in the hip or thigh continues.
    • For the unstable slips, treatment may include repositioning the ball on the end of the femur. Sometimes we use small incisions. Other times, we use surgical dislocation.
      • Our team has unique ways of treating unstable slips. We developed a technique to monitor blood flow to the femoral head. This allows us to reposition the ball on the femur using small incisions and confirming continued blood flow to the ball. This helps minimize the risk of avascular necrosis (bone death) and improves function by repositioning the ball.


  • Physical therapy: Used after surgery to help strengthen the hip and leg muscles.

Snapping Hip

What is snapping hip?

Iliopsoas tenosynovitis or snapping hip is caused from inflammation or damage to the iliopsoas tendon or rectus tendon (hip flexor tendon), which are in the anterior hip. This can cause groin pain and usually happens due to overuse. Children with snapping hip may feel or hear a click or pop when the hip moves. This may cause pain that can get worse with activity. Not all cases need treatment.

There are three types of snapping hip syndrome:

  • External snapping hip: Caused when a band of muscle catches on the outside of the hip bone when the hip is flexed. This is the most common type. It can be painless or painful.
  • Internal snapping hip: Happens when the muscles that flex the hip slide over the bony bump on the pelvic bone and cause snapping on the inner upper thigh. Most cases are not painful. Both external and internal snapping hip syndrome happen in teens or adults. Most painless clicks in babies and infants are normal but your doctor should help determine if the click is benign or a sign of hip dysplasia.
  • Intra-articular snapping: Occurs when a free-floating fragment of bone or cartilage gets caught between the joint. This type might require surgery.


How we spot snapping hip

The most common signs include:

  • Pain:
    • Pain with flexion of the hip against resistance
    • Pain during passive hip extension
  • Snapping in the front of the hip
  • Tenderness in the anterior hip, groin, or thigh

How we diagnose snapping hip

If your child or teen has symptoms of snapping hip, it’s important to get the injury properly diagnosed. The process may include:

  • A complete medical history and physical examination
  • X-ray
  • Magnetic resonance imaging (MRI)
  • Ultrasound

How we treat snapping hip

Treatment for pain from this injury may include:

  • Rest from activities that increase or cause pain. Slowly return to sports and activity once pain is gone and flexibility and strength have improved.
  • Icing the injured area for 15 to 20 minutes during a three-hour span every day.
  • Medication to reduce inflammation.
  • Physical therapy to build strength and flexibility.
  • Surgery, usually arthroscopic (minimally invasive) if needed; a surgical procedure is rarely needed.