what is DDH
developmental dysplasia of the hip
what does the head of the femur articulate with?
the acetabulum of the pelvis
what is the angle of the neck on shaft of the femur in a child?
160°
what is the angle of the neck on shaft of the femur in a male?
120°
what is the angle of the neck on shaft of the femur in females?
100°
coxa valga?
> 125°
coxa vara?
<125°
how much femoral anteversion is normal?
14°
what can increased femoral anteversion be related to?
tibial torsion
where should a mechanical hip be located?
6 mm proximal to tip of trochanter
6 mm anterior to tip of trochanter
a long standing dislocated hip will cause difficulty, midline thigh will be used.
how common is DDH?
1.5 : 1000 births
what is the ratio of male to females born with DDH?
1 male : 8 female
what side of the body is more commonly affected by DDH?
left
what are the mechanical associated factors of DDH?
- uterine contractions
- breech
- foot/ lower limb deformity
what are the physiological associated factors of DDH?
- hormonal (hormones to relax the tissues for birth, female babies are more likely to be affected by these hormones too)
- genetic
- ethnic
what are the environmental associated factors of DDH?
- swaddling
- hip healthy swaddling is recommended
how does DDH preset physically
limited abduction of the thigh.
shortening of thigh, bunching of tissues.
what is the ortolani sign?
- valid for few weeks only (soft tissue adaptations and contractures make it difficult)
- performed supine
- fex hips/ knees 90
- grasp thigh/ middle finger over trochanter
- other hand stabilises pelvis
- lift thigh/ apply traction
- gently abduct/ externally rotate
- clunk as femoral head relocates
what is the barlow test?
- valid until 6 months
- performed supine
- flex hips/ knees 90
- apply pressure to lesser trochanter with thumb
- adduct the with gentle downward pressure
- dislocation occurs
what is the telescoping sign
- performed supine
- flex hip/ knee to 90
- push femur into table
- lift away from table
- motion gives positive test
what is Galeazzi’s sign (allis’ test)
- unilateral dislocation only
- 3-18 months
- performed supine
- flex hips/ knees to 90
- knee on the affected side is lower
what is the trendelenburg sign?
- ask patient to stand on one leg
- pelvis drops on unsupported side
- trunk tilting on weight bearing leg
- positive sign of weak hip abductors
what are the three types of DDH?
- dislocated
- dislocatable
- subluxable
what test will be positive with a dislocated hip?
Ortolani sign
