Traumatic hip fracture-dislocation: A middle-term follow up study and a proposal of new classification system of hip joint associated injury.

Traumatic hip fracture dislocation is a rare injury associated with high-energy trauma. Most of these injuries should be surgically treated. Hip dislocation is an orthopaedic emergency and reduction must be performed within 6-8 hours of trauma. We performed a retrospective analysis of 69 patients with "hip joint associated injuries", treated between January 2002 and December 2016. 33 patients were assessed at a mean follow-up of 36.9 months (range 18-132) after surgery. We propose a new classification system in which, different patterns of fracture (head and/or neck and/or acetabular) are described according to different types of hip dislocation. This anatomical-descriptive classification system is based on the concept of hip as a complex anatomical district and contains all possible traumatic injuries associated with hip dislocation. It includes isolated hip dislocation, hip dislocation with femoral head or neck fracture or hip dislocation with acetabular fracture and femoral head fracture. There are 4 groups: Each one of the previous groups is composed by different subgroups. Post-traumatic osteoarthritis is the most common complication of these hip injuries, followed by avascular necrosis of femoral head and heterotopic ossification. The bad prognosis depends on the type of trauma rather than surgical treatment.