B. Developmental dysplasia of the hip – Explanation
Developmental dysplasia of the hip (DDH)
- Formerly referred to as congenital dislocation of the hip (CDH). DDH is now the
preferred term to reflect that DDH is an ongoing developmental process. - Defined simply as abnormal growth of the hip
- More common in the left hip
Risk factors
- An important risk factor to remember is vaginal delivery of babies with breech.
- 80% of cases occur in girls
Barlow test: attempts to dislocate an articulated femoral head
Ortolani test: attempts to relocate a dislocated femoral head.
Ultrasound is used to confirm the diagnosis if clinically suspected. This is used up to
4.5 months of age because the hips remain cartilaginous up to this time. After 4.5
months, an anteroposterior pelvic radiography is more useful.
Management
- Pavlik harness in children younger than 4-6 months
- Surgery is reserved for older children
COMPARING LIMPS IN CHILDREN
The table below gives good keywords and hints that the examiners would include to
point you towards a specific diagnosis.
| Developmental dysplasia of the hip (DDH) |
Perthes’ disease | Slipped Upper Femoral Epiphysis (SUFE) |
|
|---|---|---|---|
| Age | 0 to 5 years old | 5 to 10 years old | 10 to 15 years old |
| Pain | Painless | Chronic pain (slowly developing pain) |
Painful |
| Risk factors | Breech delivery | Obese | |
| On examination | Unequal skin folds One leg shorter |
Stiffness and reduced range of hip movement |
The affected limb will be shorter and lies in external rotationAbduction is limited. When the hip is flexed, it will rotate externally |
| Transient synovitis |
Juvenile idiopathic arthritis |
Septic arthritis | |
|---|---|---|---|
| Description | Acute hip pain associated with viral infection (most commonly an upper respiratory tract infection) |
Arthritis occuring in someone who is less than 16 years old that lasts for more than three months |
Acute hip pain associated with systemic upset |
| Fever | Present (usually
mild) |
Present if systemic- onset JIA (fever canoccur at the same time every day with a spontaneous rapid return to baseline) |
Present (continuous fever) |
| Features usually given in exam |
Pain on weight- bearing but not atrest |
Blanching rash (salmon pink rash) |
Very unwell child |
