Congenital Dysplasia of the Hip (CDH)

This is also known as Developmental Dysplasia of the Hip (DDH). It's an abnormality of the hip joint in which the femoral head and acetabulum don’t articulate properly during development. This leads to hip instability and the tendency for subluxation (partial dislocation) or complete dislocation.

It's usually diagnosed either during newborn examinations or later in childhood when the child presents with hip asymmetry, reduced ROM, or a limp.

Risk factors - 5 F's:

• Female

• Firstborn

• Family hx

• Fanny first (Breech presentation)

• Fluid (Oligohydramnios)

Screening

Features in a newborn suggestive of CDH are:

• Different leg lengths

• Restricted hip abduction on one side

• Significant bilateral restriction in abduction

• Difference in knee level when hips are flexed

• Clunking of hips on special tests

Special tests:

• Barlow test (posterior dislocation) – Babe on back with hips adducted, and hips and knees flexed to 90 degrees. Gently press down on knees to see if femoral head dislocates posteriorly.

• Ortolani test (anterior dislocation on hip abduction) – Baby on back with hip and knees flexed. Hold knees with thumbs on inner thigh and four fingers on outer thigh. Gently abduct the hips and apply pressure behind legs with fingers to see if hips dislocate anteriorly.

Investigations

To diagnose it, a Hip US is done. In older infants, an XR is typically better.

Most cases are self-limiting and resolve within the first few months of life.

Management

Most cases are self-limiting and resolve within the first few months of life.

In more severe cases:

• If < 6 months of age - Pavlik harness, which holds the femoral head in place to allow the acetabulum to develop in a normal shape (keeps hips flexed and abducted), and is removed once hips are more stable (Usually after 6-8 weeks)

• Surgery required if harness fails or baby diagnosed after 6 months of age