D.D.H (Developmental Dysplasia of the Hip)

• Anatomy of the hip

• DDH includes:

1- Dislocation

2- Subluxation

3- Acetabular dysplasia

• Incidence

Instability 5-20 per 1000 livebirths

After 3 weeks 1-2 per 1000 infants

( i.e spontaneous correction)

Girls ⁄ Boys 7 ⁄ 1

Left > Right

20% bilateral

Aetiology

1- Genetic factors( families, even in entire population)

2- Hormonal changes in late pregnancy→ lig. laxity

3- Intrauterine malposition( breech + extended legs)

4- Postnatal factors( swaddling+ Beshka)

PathologyAcetabulum (1) Shallow(looks like a saucer instead of a

cup) (2) The roof slopes too steeply (3) AntevertedFemoral head (1) Dislocated(post. and sup.) (2) Delayed ossific centerFemoral neck : Unduly antevertedCapsule : (1) Stretched (2) ± hourglass by iliopsoasLimbus : Superiorly the acetabular labrum and its capsular

edge may be pushed into the socket by the dislocated femoral

head . This fibrocartilagenous structure may obstruct closed

reduction.Lig. Teres : (1) Elongated (2) Hypertrophied

• Clinical features

Neonate : (1) Ortolani’s test +ve

(2) Barlow’s test +ve

Late featuresUnilateral DDH(1)Asymmetrical skin creases

(2) Difficulty in applying napkins( ↓ abduction)(3) Shorter leg(4) Delayed walking(5) Limping (B) Bilateral DDH (1) ↓abduction (2) Delayed walking (3) Waddling gait (4) Wide perineal gap

X- Ray (A) Acetabulum : Shallow and sloping(Acetabular roof angle normally< 30)

(B)Femoral head : Underdeveloped and out Perkin’s lines = Vertical line at the outer edge of

acetabulum Hilgenreiner’ line = Horizontal line through the

triradiate cartilages. Normally the head is medial to vertical and below the horizontal

(C) Shenton’line is broken

(Inferior border of superior ramus

and inferior border of the neck)

(D) Von Rozen line = Hips abducted 45

Femoral shaft should point into the acetabulum

Treatment0-6 months6 m – 6 years> 6years0-6 months+ve Ortolani+ve Barlow+ve US Double napkins OR Abduction pillow for 6 weeksStable hip = follow-up for 6 monthsPersistent instability = Splint for 3-6 months (Pavlic

harness)

• Principles– Reduction before applying it– 100 flexion + slight abduction– Extreme positions are avoided( Frog position

is only for frogs)– Some movement is allowed

6monthes- 6 yearsReduce + hold reducedClosed reduction Gradual abduction 3 weeks Hip spica 6weeks followed by few months Splint

which prevents adduction ( 60 flexion 40 abduction 20 internal rotation )Open reduction if closed reduction failed + hip spica 3 months

6years

Unilateral up to 10 years surgery

Bilateral = No treatment

1- Symmetrical deformity

2- Less noticeable

3- Failure in one side leads to asymmetrical deformity

4- In future THR