Diagnosing developmental hip dysplasia early can make all the difference for a child’s future mobility and quality of life. Understanding when and how this condition is detected helps parents ensure their babies receive the care they need to develop healthy, pain-free hips.

Introduction: Who Should Undergo Diagnostics

Developmental dysplasia of the hip, often called DDH, is a condition where the hip joint doesn’t form properly in babies and young children. The ball at the top of the thighbone, known as the femoral head, doesn’t fit snugly into the hip socket, called the acetabulum. This poor fit can range from mild looseness to complete dislocation, where the ball slips entirely out of the socket.^[1]

Every newborn baby should undergo hip screening as part of routine care. Healthcare providers check all newborns’ hips during their first physical examination within 72 hours of birth, and then again at six to eight weeks of age. These screenings happen even when there are no obvious signs of problems, because DDH often causes no pain in babies and can be difficult to notice at home.^[3]

Some babies have a higher chance of developing hip dysplasia and need extra attention. Girls are affected much more often than boys, with females being two to four times more likely to have the condition. First-born children also face increased risk, as do babies who spent time in the breech position during pregnancy, especially after 28 weeks. If a parent or sibling had hip problems as a child, this raises the risk significantly—by about 12% if a parent had DDH, and by over 6% if a sibling was affected.^[2][3]

Babies born in breech position deserve special attention because they are ten times more likely to develop hip dysplasia than babies born head-first. The American Academy of Pediatrics now recommends ultrasound screening for all female breech babies. If you had twins or multiple babies and one was breech, each baby should have an ultrasound scan of their hips by the time they’re four to six weeks old.^[2][3]

Sometimes hip problems don’t become noticeable until a child grows older and becomes more active. Athletes who place heavy demands on their hips through activities like dance, hockey, football, soccer, or track and field may experience symptoms sooner than less active children. The age when older children and young adults with hip dysplasia begin noticing symptoms depends on both the severity of their condition and their activity level.^[9]

Diagnostic Methods

Physical Examination

The first and most important diagnostic tool for hip dysplasia is a careful physical examination. During well-baby visits, healthcare providers perform specific maneuvers to check if the hip joint is stable and properly positioned. These gentle tests should not cause discomfort to the baby, though they may seem unfamiliar to new parents.^[3]

Two main examination techniques help doctors identify hip problems in newborns and young infants. The Ortolani test involves gently moving the baby’s legs to see if a dislocated hip can be repositioned back into the socket. During this test, the examiner may feel a “clunk” as the femoral head drops into place. The Barlow maneuver checks whether a hip that appears normal can be easily pushed out of its socket, revealing instability. Both tests are performed with the baby lying on their back with knees bent.^[4][14]

Healthcare providers also look for physical signs that might indicate hip dysplasia. They check whether one leg appears shorter than the other, though it’s important to know that in most children with DDH, the legs are actually the same length—one may just look shorter because the bones are positioned differently. Doctors examine the range of motion in each hip, noting if one leg doesn’t spread away from the body as easily as the other. This restricted movement, called asymmetric abduction, happens when the femur runs into the pelvis because it’s not properly seated in the socket.^[4][27]

The appearance of skin folds can provide visual clues. Uneven or extra creases in the skin around the thighs, buttocks, or where the legs meet the body may suggest that the hips are positioned differently. However, these asymmetric skin folds don’t always mean a child has DDH or any other condition—they can appear in babies with completely normal hips too.^[1][27]

For older children who are walking, doctors watch how they move. A child with undiagnosed hip dysplasia may limp when they walk, or they might waddle, especially if both hips are affected. Unlike many painful conditions, DDH typically doesn’t cause pain in young children, so limping isn’t usually due to discomfort. However, teenagers and young adults with hip dysplasia sometimes develop hip pain over time as the condition affects the joint.^[27][9]

Ultrasound Imaging

When a physical examination suggests hip instability, or when a baby has risk factors for DDH, an ultrasound scan becomes the next step in diagnosis. Ultrasound uses high-frequency sound waves to create real-time pictures of the hip joint, allowing doctors to see the soft tissues, cartilage, and positioning of the bones. This imaging method is especially valuable for babies because much of an infant’s hip is still made of cartilage rather than bone, which doesn’t show up well on X-rays.^[4][14]

For infants less than six months old, ultrasound is usually the most reliable diagnostic tool. Healthcare providers typically perform hip ultrasounds between four and six weeks of age for babies who need additional screening. This timing is important because some hip looseness that appears in the first few weeks of life resolves on its own without treatment. Babies are often born with hips that feel loose when moved around—a condition called neonatal hip laxity—because the bands of tissue connecting bones, called ligaments, are extra stretchy from exposure to the mother’s hormones during pregnancy. This looseness usually improves by four to six weeks of age and isn’t considered true DDH.^[1][3]

Ultrasound screening is recommended for specific groups of babies. All babies whose hips feel unstable during physical examination should have an ultrasound between four and six weeks old. Additionally, babies with a family history of childhood hip problems should receive ultrasound screening, as should babies who were in breech position after 28 weeks of pregnancy. Sometimes a baby’s hip stabilizes on its own before the scheduled scan, but they should still be checked to make sure everything is developing normally.^[3]

X-Ray Imaging

As babies grow older and their bones begin to harden, X-rays become more useful for diagnosing hip dysplasia. X-rays use small amounts of radiation to create images of bones and can show the shape and position of the hip joint. Healthcare providers usually recommend X-rays for children approximately six months of age and older, when more of the hip has turned from cartilage into bone that can be seen on the images.^[4][14]

Modern X-ray equipment uses very low doses of radiation and is considered safe for infants and children. The images help doctors see if the hip socket is shallow, if the ball of the hip is properly positioned, and whether the bones are developing normally. X-rays can often be performed right in the orthopedic surgeon’s office during the appointment, which makes the diagnostic process more convenient for families.^[4]

For older children, teenagers, and adults with suspected hip dysplasia, X-rays remain an important diagnostic tool. They can reveal changes in the underlying bone structure that might have developed over time due to abnormal hip mechanics. These images help doctors determine whether the condition can be treated with surgery to correct the joint alignment, or whether the joint damage has progressed to the point where other treatments might be needed.^[9]

Advanced Imaging

In some cases, healthcare providers may order additional imaging tests to get a more detailed look at the hip joint. Magnetic Resonance Imaging, or MRI, uses magnets and radio waves to create detailed pictures of both bones and soft tissues. MRI scans can be particularly helpful for evaluating older children and adults with hip pain, as they can show damage to the cartilage that cushions the joint and reveal problems with the labrum, a ring of soft tissue that helps hold the ball in the socket.^[11]

Distinguishing DDH from Other Conditions

Part of the diagnostic process involves making sure that hip problems are actually due to developmental dysplasia and not some other condition. Hip dysplasia is sometimes confused with hip impingement, which occurs when extra bone grows on the acetabulum or femoral head. This irregular shape creates friction within the joint and wears down cartilage. Some patients have both conditions, which can make diagnosis more complex since both cause hip pain and are easy to confuse. However, they require different treatments.^[9]

Healthcare providers also need to distinguish between different severities of DDH itself. The condition exists on a spectrum. In the most severe cases, the hip is completely dislocated, meaning the head of the femur is entirely out of the socket. In other cases, the hip is dislocatable—it lies within the socket but can easily be pushed out during examination. In mild cases, the hip is subluxatable, meaning the bone can be moved within the socket but doesn’t fully dislocate. Finally, some hips are simply dysplastic, meaning the socket is underdeveloped or shallow but the ball hasn’t slipped out of position.^[2][12]

Diagnostics for Clinical Trial Qualification

When children or adults with hip dysplasia participate in clinical trials or research studies, the diagnostic requirements may be more detailed and standardized than those used in routine care. Clinical trials test new treatments or compare different approaches to managing DDH, and they need precise, consistent methods to measure the condition and track changes over time.

Research protocols typically specify which imaging methods must be used and at what intervals. For infant studies, ultrasound measurements might be standardized using specific angles and measurements of the hip joint that quantify how well the femoral head sits in the acetabulum. These measurements allow researchers to objectively compare the severity of hip dysplasia between different babies and to track whether the condition improves with treatment.^[4]

X-ray studies in clinical trials often include specific views of the hip taken from particular angles. Researchers measure various angles and relationships between bones to classify the degree of dysplasia precisely. These standardized measurements help ensure that all participants in a study are diagnosed and evaluated in the same way, making the research results more reliable and comparable across different medical centers.

Physical examination findings also need to be documented systematically in clinical trials. Researchers use standardized forms to record the results of tests like the Ortolani and Barlow maneuvers, ensuring that different examiners describe their findings in consistent ways. They may also measure and record range of motion in degrees, leg length differences in centimeters, and other objective measures that can be compared before and after treatment.^[14]

For studies involving older children and adults, clinical trial protocols might require additional assessments beyond basic imaging. These could include questionnaires about pain levels, daily function, and quality of life. Some trials use advanced imaging techniques like MRI to evaluate the condition of cartilage and other soft tissues in detail, creating baseline measurements that help researchers understand whether a treatment is working.^[11]

Clinical trials may also require documentation of risk factors and family history to help researchers understand which patients are most likely to benefit from particular treatments. This information gathering is more comprehensive than what happens during routine care appointments, as research aims to identify patterns and factors that predict treatment success. Participants typically undergo more frequent follow-up appointments and imaging studies than patients receiving standard care, allowing researchers to monitor progress closely and detect any problems early.^[4]