In pediatric/neonatal orthopedics it is used to describe unstable/dislocatable hips and poorly developed acetabula.
The scolex bears four radially arranged suckers (acetabula) that surround the rostellum.
In ambulatory mammals the acetabula are shallow and open to allow a wider range of hip movements, including significant abduction, than in cursorial mammals.
The acetabula are shallow, and posterior to them is a prominent tubercle, positioned between the posterior edge of the supraacetabular process and anterior part of the posterior iliac process.
