Terminology for developmental dysplasia of the hip

Term	Definition
Dysplasia	Abnormality of the shape of the hip joint (usually shallowness of the acetabulum, involving the superior and anterior margins).
Subluxatable/subluxable	The femoral head is reduced (ie, within the acetabulum) at rest but can be partially dislocated or subluxated with examination maneuvers. This is a hip with mild instability or laxity.
Dislocatable	The femoral head is reduced at rest but can dislocate in other positions or with examination maneuvers. This is a hip with instability.
Subluxation	The femoral head is partially outside of the acetabulum but remains in contact with it.
Reducible	The hip is dislocated at rest, but the femoral head can be positioned into the acetabulum with manipulation (generally flexion and abduction).
Dislocation	Complete loss of contact between the femoral head and the acetabulum.

Graphic 88588 Version 3.0