Developmental dysplasia of the hip (DDH), formerly known as congenital dislocation of the hip, is a spontaneous dislocation of the hip that occurs before, during, or shortly after birth. It is more common in females, in the firstborn, and in those with a family history. Risk factors include breech positioning and maternal relaxin hormone exposure. Clinically, it presents with leg length discrepancy, limited hip movement, or a clicking sound. Radiographs show a delayed ossification center, sloped acetabulum, and displaced femoral head. Treatment depends on age, ranging from Pavlik harnesses or closed reduction for infants to open reduction and femoral shortening for older children.
1. DEVELOPMENTAL
DYSPLASIA OF HIP
(DDH)
● this is a spontaneous dislocation of the hip occurring before,during or shortly after
birth.
● congenital dislocation of hip (CDH) has been changed DDH to indicate that not all
cases are present at birth & that some cases can present later in infancy or childhood.
2. EPIDEMIOLOGY
● More common in Western countries, being one of the commonest congenital
disorder.
● Uncommon in India & other Asian countries.
● More common in Females ( M:F = 1:5 )
● Higher Risk if Family History of DDH (+)
● More common in 1st born babies
● Bilateral in 20% cases.
3. AETIOLOGY
1. HEREDITARY predisposition leading to Joint laxity.
2. HORMONE induced joint laxity.
○ DDH more common in females (maybe) due to the fact that Maternal Relaxin
hormone ( a ligament relaxing hormone in the mother during pregnancy)
crosses the Placental Barrier to enter the foetus. The foetus being a female
has the hormone acted on the foetus’s joint the same way it does for the
mother. Producing Joint laxity and later dislocation.
3. BREECH malposition
○ incidence of hip 10x more common in newborns with breech presentation
than those with vertex presentation. (maybe) due to the possibility of foetal
legs being pressed inside the uterus in such a way that if the hips are lax ,
dislocation may occur.
4. PATHOLOGY
● dislocation at birth (classic
CDH) primarily due to
hereditary faulty development
of the acetabulum, and are
difficult to treat.
● dislocation after birth is due to
underlying joint laxity with a
precipitating factor causing the
dislocation, following changes
are seen in a dislocated joint.
1. Femoral head dislocated upwards
& laterally, its epiphysis is small
and ossifies late.
2. Femoral neck is excessively
anteverted.
3. Acetabulum is shallow, with a
steep sloping roof.
4. Ligamentum teres is
hypertrophied.
5. Fibrocartilaginous labrum of
acetabulum (limbus) may be folded
into the cavity of the acetabulum
(inverted limbus)
6. Capsule of hip is stretched.
7. Muscles around the hip, especially
the adductors undergo adaptive
shortening.
5. CLINICAL FEATURES
1. AT BIRTH : Signs of a dislocated or dislocatable hip
2. EARLY CHILDHOOD : Asymmetry of creases in groin,
limitation of movements of the affected hip, or a click every
time the hip is moved.
3. OLDER CHILD : Parents notice that the child walks with a
“peculiar gait” though there is no Pain.
7. RADIOLOGICAL
FEATURES
● below the age of 1 year old, since
the epiphysis of the femoral head is
not ossified, it is difficult to
diagnose a dislocated hip on plain
X Ray. Von Rosen’s view may help.
● USG helps in early diagnosis at
birth.
● In an older child, the following are
the important X Ray findings:
● Delayed appearance of the
ossification centre of the
head of the femur.
● Retarded development of
the ossification centre of the
head of the femur.
● Sloping acetabulum.
● Lateral and upward
displacement of the
ossification centre of the
femoral head.
● A break in the Shenton’s line.
8. An anteroposterior radiograph in an 8-month-old girl demonstrates bilateral
developmental dysplasia of the hip, with the left hip worse than the right hip.Note the
upward slanting sourcil bilaterally. The right femoral head is concentrically located within
its dysplastic acetabula. The left femoral head is superolaterally dislocated.
9. DIAGNOSIS
Diagnosis is easy in an older child, but may be very difficult in
younger children, especially during infancy. This is because of
subtle clinical findings and difficulties in interpreting X rays of these
children.
10. TREATMENT PLAN
BIRTH TO 6 MONTHS
● PAVLIK HARNESS
● CLOSED REDUCTION
6 MONTHS TO 6 YEARS
● CLOSED REDUCTION TILL 2 YEARS
● > 2 YEARS OPEN METHODS +/- FEMORAL SHORTENING, ACETABULAR
RECONSTRUCTION
6 YEARS TO 10 YEARS
● WE DECIDE WHETHER TO TREAT THE DISLOCATION OR NOT, NO TREATMENT IS
INDICATED IN B/L DISLOCATIONS DUE TO THE REASON THAT THE LIMP IS LESS
NOTICEABLE, THEY TEND TO LIVE NORMAL LIVES TILL THEIR 40S / 50S, RESULTS
OF SURGERIES REMAIN UNPREDICTABLE & A SERIES OF OPERATIONS REQD.
11 YEARS ONWARDS
● INDICATION FOR TREATMENT IN THESE PATIENTS IS PAIN. IF ONLY 1 HIP IS
AFFECTED, A TOTAL HIP REPLACEMENT MUST BE PRACTICAL ONCE
ADULTHOOD IS REACHED. SOMETIMES ARTHRODESIS OF THE HIP DONE.
