Traumatic dislocation of hip joint following low-velocity trauma, similarities to glenohumeral instability

Acute posterior hip dislocation following low velocity trauma in a young healthy adult is a rare injury. Almost 30 cases previously have been described in the literature. They are usually associated with prior trauma to the hip joint and will lead to recurrent instability after relocation. This injury is similar to shoulder instability: lesions and anomalies present in the hip joint with posterior instability are identical to the ones in the shoulder with instability. These are Bankart-like lesion of the posterior labrum, defect in ischiofemoral ligament similar to inferior glenohumeral ligament laxity of the shoulder, relative retroversion of femoral neck angle similar to loss of retroversion of the humeral neck and, finally, Pipkin type 1 fracture of the femoral head resembling a Hill-Sachs lesion of the humeral head. Successful treatment of this injury depends on addressing these pathologies. We present three cases of acute posterior hip dislocation in young adults after low-energy trauma, which presented to our unit over a 4-year period, and a review of another 21 cases of similar injury previously described in the literature. We will demonstrate these lesions and discuss the investigation and treatment modalities for posterior instability of the hip joint. We conclude that hip dislocation caused by low-energy trauma must be investigated and treated to avoid recurrence of dislocation and associated complications.