Text: Maria Braylyan

Our consultant: Nikolay Nikolaevich Shavga, Doctor of Medical Sciences, Associate Professor, Orthopedic Traumatologist of the highest category, Vertebrologist, holder of the title Om Emerit.

Until the first half of the last century, doctors diagnosed only the severe form of dysplasia — congenital hip dislocation. In those years, “mild forms” of the disease were not detected and, accordingly, were not treated. Starting from the 1970s, specialists introduced the modern term — “hip dysplasia,” which implies not only dislocation but also subluxation and preluxation of the hip joint.

A few details
Hip dysplasia is a congenital insufficiency of the joint caused by its improper intrauterine development. Dysplasia is a somewhat abstract concept because it encompasses joint insufficiency of varying severity — from mild (slight underdevelopment of the elements of the hip joint), which is easy and quick to treat and sometimes heals on its own, to extremely severe (congenital dislocation of the femoral head), where even timely treatment cannot fully restore the joint, leading to disability.

Risk Factors

The condition can be hereditary (in 30% of cases), which is why babies whose parents suffered from this disorder have a 10 times higher chance of being born with hip dysplasia. Most often, these joint disorders occur in girls (up to 80% of detected cases). The perinatal period and the course of delivery also play a significant role in the development of the pathology. Complications during pregnancy such as toxicosis, as well as medical intervention to prevent premature birth, significantly increase the risk. Additionally, babies born in breech presentation (feet first) are 10 times more likely to have this pathology. It is important to note that usually the left hip joint is affected—in 60% of cases, while the right or both joints are involved in only 20%. Firstborns are also at higher risk due to higher secretion of the hormone relaxin in the mother’s body, which relaxes the joints and ligaments not only in the woman but also in the fetus. In subsequent pregnancies, relaxin is produced in much smaller amounts. Other risk factors include babies weighing more than 3500 grams at birth and those with foot deformities.

Experts have also found a clear correlation between the frequency of the disease and the standard of living and environmental conditions in the region. For example, in developed countries, the disorder affects about 2-3% of the population, while in the Republic of Moldova, hip dysplasia (ranging from mild to severe) is diagnosed in nearly 10-15% of children.

Anatomical Features

Even a healthy newborn’s hip joint is an immature biomechanical structure: the socket is flattened and positioned more vertically compared to an adult joint, and its ligaments are overly elastic. The femoral head is held in the socket by tension in the joint capsule and the ligamentum teres (round ligament of the hip joint). A cartilage plate called the “limbus” prevents the femur from shifting upward. Hip dysplasia involves a flatter and more slanted socket; overly elastic ligaments and joint capsule fail to hold the femoral head in place, which then shifts upward and outward.

The limbus becomes everted (displaced upward) and deformed, losing its ability to keep the femoral head in place. Certain movements can cause the femoral head to partially leave the socket, a condition known as “subluxation.” In severe dysplasia, the femoral head fully dislocates from the socket, the limbus folds inward below the femoral head, and the socket fills with fatty and connective tissue, complicating treatment.

Notes for Parents

Ideally, an orthopedic doctor first examines the baby in the maternity ward to identify gross musculoskeletal abnormalities or predisposition to orthopedic diseases. However, pelvic problems in very young babies are not always immediately visible. As the child grows, their joints and ligaments change, so parents should be aware of warning signs that may indicate hip dysplasia:

• Up to one month: increased muscle tone in the back, extra crease on the buttocks, asymmetrical buttock creases, incomplete leg spreading when lying on the back with knees bent, visually shorter leg on one side. The child’s torso may be C-shaped, head tilted to one side, often clenching one fist.
• From three to four months: a clicking sound when bending legs at the knees and hips, flat valgus foot (heel not aligned with the shin), one leg still appears shorter.
• Older than six months: tendency to stand and walk on tiptoes, feet turning inward or outward during walking, pigeon-toed gait, excessive lumbar spine curvature, “duck-like” gait, slouching, one leg appearing shorter due to tilted pelvis, limping in severe cases.

Remember, these signs may also indicate other orthopedic or neurological disorders. Therefore, regular check-ups at 1, 3, 6, and 12 months by specialists are crucial. Only a qualified doctor can distinguish between conditions.

Diagnosis

As mentioned, specialists (orthopedist and neonatologist) should thoroughly examine newborns in the hospital for congenital hip pathology. Regular pediatric orthopedic visits at 1, 3, 6, and 12 months allow objective assessment of musculoskeletal development and timely intervention.

During consultations, the doctor performs a clinical examination and may order an ultrasound (US) of the hip joints—the safest diagnostic method, but with limited accuracy (50-70% sensitivity). X-rays remain the most reliable diagnostic tool, crucial for timely diagnosis and treatment. Radiation exposure from X-rays is minimal and comparable to 1-2 weeks of sunlight exposure and far outweighed by the risk of missing pathology that could lead to disability. Children older than 3 months may be recommended an X-ray to detect even subtle hip problems.

Treatment

If dysplasia is not diagnosed within the first six months, joint damage will worsen, the leg will shorten further, and the child may develop a pathological “duck-like” gait or intermittent limping (in bilateral dislocation).

The younger the child, the easier the correction. In mild cases, the joint can often normalize on its own in the first three months with proper care (avoiding tight swaddling, regular massage, special exercises, and spreading the legs to the correct position). Early treatment primarily involves “free” swaddling that keeps the baby’s legs apart—sometimes by adding an extra diaper.

More severe cases require special orthopedic devices. The later treatment starts, the more complex the devices (such as Mirzoyeva splint, Pavlik harness) that may be needed. If these are ineffective, a special plaster cast is applied to hold the hips fully spread and bent at a right angle. This method is reserved for severe cases or late diagnosis when gentler treatments no longer work.

Early diagnosis and treatment are critical: if dysplasia is detected in the first three months, 95% of children achieve full recovery within 3-6 months of therapy! After cast removal, each child undergoes rehabilitation (massage, exercises, physiotherapy) or surgery if dislocation persists. Even after correction, children remain under orthopedic follow-up to prevent complications.

Prevention

The formation of a baby’s joints depends greatly on the mother’s nutrition and pregnancy health. Thus, a balanced diet and regular medical supervision during pregnancy are vital. How the baby is cared for postnatally is also crucial.

Traditional tight swaddling (to help the baby sleep or keep legs straight) can cause or worsen hip dysplasia, even in mild cases. In contrast, in many Asian and African cultures where babies are carried on the belly or back and not tightly swaddled, hip dysplasia is rare because the joints develop in ideal conditions.

It’s also important for parents to do age-appropriate gymnastics with their baby from the first days of life to support harmonious overall development.

Nota Bene!

The word “dysplasia” means a disorder in the formation or development of something. In the case of hip dysplasia (HD), this can include:

• defects in the structure of the acetabulum (acetabular dysplasia);
• immaturity of the femoral head;
• impaired movement within the joint (rotational dysplasia).

As a result of these abnormalities, the hip joint may develop conditions such as:

• pre-dislocation (a readiness for dislocation);
• subluxation.
• dislocation (actual dislocation).

Remember!

Hip dysplasia in children can be suspected if any of the following are observed:

• asymmetry of skin folds on the buttocks.
• apparent “shortening” of one leg.
• a clicking sound when the legs are spread apart.
• limitation in the ability to spread the hips.

Note #1:
In Asian and African countries, where women traditionally carry their infants on their backs or stomachs (meaning the baby is constantly in a sitting position with legs widely spread), hip dysplasia is virtually nonexistent among children.