Barlow dislocates, Ortolani relocates
Expansion
Barlow: with the hip flexed and adducted, apply gentle posterior pressure. A dislocatable hip slips out. This test provokes dislocation.
Ortolani: with the hip flexed, abduct while lifting the greater trochanter forwards with the fingers. A clunk as an already dislocated hip relocates is positive.
Both are performed on one hip at a time, on a relaxed baby, and both become unreliable after about 3 months as soft tissue contractures develop.
Later signs, after the neonatal period
- Asymmetrical skin creases in the thigh and groin
- Limited abduction in flexion, which is the most reliable later sign
- Galeazzi (Allis) sign: apparent shortening of the femur with the hips and knees flexed
- Leg length discrepancy and a Trendelenburg or waddling gait once walking
Risk factors requiring ultrasound at 6 weeks even if the examination is normal
- Breech presentation at or after 36 weeks, or breech delivery
- First degree family history of hip problems in early life
- Multiple pregnancy where either twin was breech
Female sex, oligohydramnios, high birth weight and other packaging deformities such as talipes and torticollis are additional associations.
Ultrasound is the imaging of choice under 4.5 months, since the femoral head is cartilaginous and radiographs are uninformative. Treatment with a Pavlik harness is highly effective if started early, which is the entire justification for screening.