Anatomy of the zona orbicularis of the hip: a magnetic resonance study.

Purpose: This study aimed at describing the anatomy of the zona orbicularis (ZO), based on magnetic resonance arthrography (MRA) and magnetic resonance imaging (MRI) scans and to assess the presence of synovial folds in relation to the ZO.

Methods: A retrospective review was performed using consecutive hip and pelvic MRA and MRI examinations from our institution. We identified 25 normal scans of each variety.

Secondary capsular laxity of the hip.

We describe a hip condition with a recognisable pattern of clinical signs and radiological findings thought to result from chronic capsular injury. Between June 2006 and October 2009, ten patients (11 hips), four men and six women, were identified with an abnormality of external rotation at the hip joint. A detailed history and clinical examination was undertaken for each patient.

A manoeuvre to facilitate acetabular component retrieval following intra-pelvic migration.

Acetabular component extraction following intra-pelvic migration of a total hip replacement can be hazardous to pelvic tissues, vessels and organs. Acetabular component removal is usually performed using an abdominal retroperitoneal approach. We describe a closed reduction of the acetabular component using a traction/manipulation technique.