Developmental Dysplasia of the Hip (DDH) in Infants: Timely Diagnosis and Treatment Crucial

Understanding Developmental Dysplasia of the Hip (DDH) in Infants

Developmental Dysplasia of the Hip (DDH), a condition involving abnormal hip development in infants, is a serious issue where timely identification and proper treatment are paramount for a child's healthy future. This condition can manifest in various ways, from hip instability to complete dislocation of the femoral head (the top of the thigh bone).

Early diagnosis allows the hip joint adequate opportunity to develop normally, whereas delays increase the risk of walking difficulties and permanent hip deformity. Several risk factors contribute to the development of DDH, including breech birth position (especially frank breech), being female, a family history of DDH, first pregnancies, and low amniotic fluid levels during pregnancy (oligohydramnios).

Additionally, musculoskeletal abnormalities like torticollis (stiff neck) or foot deformities can be associated with DDH. Tightly swaddling infants with their legs straightened can also hinder normal hip development.

Symptoms and Diagnostic Tests for DDH in Infants

For newborns up to approximately three months old, the Barlow and Ortolani tests are crucial for hip examination. The Barlow test assesses hip instability by attempting to dislocate the hip in a specific manner, while the Ortolani test checks if a dislocated hip can be relocated back into its socket.

These tests may become less effective as the infant grows. After three to six months of age, a reduced ability to abduct the hips (move the leg outwards) becomes a significant clinical sign. Uneven skin folds on the thighs or buttocks alone are not considered sufficient for diagnosing DDH.

When a child begins to walk, DDH symptoms can become more apparent, including limping, a wobbly gait, one leg being shorter than the other (limb length discrepancy), or a Trendelenburg sign (the hip on the affected side dropping when standing).

If both hips are affected, subtle changes in gait may occur, and an abnormal tilt in the upper part of the pelvis can be observed. In cases of unilateral dislocation, tests like the Galezzi or Allis test can estimate the difference in length between the two legs.

Imaging Techniques Based on Age

The choice of imaging technique for diagnosing DDH depends on the child's age. Ultrasound is highly useful up to four to six months of age, before the ossification of the femoral head begins. It helps assess hip structure and stability during movement.

Dynamic ultrasound can also evaluate hip mobility. The Graf classification is used to assess hip morphology and development in ultrasound scans. After approximately four to six months of age, X-rays become more effective.

X-rays analyze parameters such as the acetabular index (width of the hip socket), Shenton's line (a key line of the hip joint), the position of the femoral head, and the development of the ossification nucleus (the beginning of femoral head formation).

DDH Treatment: Based on Age and Condition

The treatment for DDH is determined by the child's age, hip stability, severity of dislocation, and reducibility. For infants from birth to approximately six months, if the hip can be stabilized (reducible DDH), the Pavlik harness is typically the first treatment option.

This device helps maintain the hips in the correct position for normal development. In children aged six to 18 months, if the hip can be relocated non-surgically (closed reduction), a hip spica cast may be used afterward. For children over 18 months with more severe dislocations, open reduction, involving surgical correction of the hip, is often necessary.

In some complex cases, pelvic or femoral osteotomies (bone-cutting surgery) may be required to correct the hip's structure. It is important to note that treatment is not solely based on age but on a thorough evaluation of each child's specific physical condition and the severity of the hip deformity.

Differentiating DDH from Infections is Necessary

It is crucial to understand that if an infant suddenly stops moving one leg, DDH may not be the sole cause. Symptoms like fever, extreme irritability, severe pain, and elevated C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) in blood tests could indicate serious infectious conditions such as septic arthritis (joint infection), osteomyelitis (bone infection), or pyomyositis (muscle infection).

Fractures or other types of injuries can also lead to such situations. DDH is a developmental and relatively chronic problem, whereas infections often present acutely with systemic symptoms. Therefore, correctly differentiating between these two conditions and ensuring timely, appropriate diagnosis and treatment play a vital role in the child's normal hip development and future mobility.