Fracture-dislocations of the femoral head

Abstract

This review describes bone and nerve injury mechanisms during a femoral head fracture-dislocation and outlines a novel classification system that uses computed tomography scanning (CT scan) to help determine how to best treat these fractures in an emergency setting or in chronic cases. A series of 55 cases with CT scan performed in the emergency department (ED) and an average follow-up of 9 years (range 3-13) was used as a basis to develop the classification system; this system takes into account the size of the fragments and any associated acetabular wall or femoral neck fractures. The suggested course of action is based on the CT scan results after the hip joint is reduced. Conservative treatment is indicated every time the head fragments and any potential acetabular wall fragments are properly reduced and there are no foreign bodies (37.7%). Osteochondral head fragments below the fovea must be removed (36.3%). Fragments that are one-third or one-quarter of the head size can either be removed (7.2%) or reduced and fixed (5.4%). A novel medial approach is described that provides minimally invasive access to the anterior-inferior part of the femoral head, which should extend the indications for preservation of one-third head fragments. If the femoral neck is also fractured or a one-half head fragment exists in elderly patients, a total hip replacement should be considered right way (9%). At the latest follow-up, osteoarthritis was present in 43.7% of cases, but was mostly well tolerated - 94% of patients had a WOMAC score between 80 and 100 with signs of osteoarthritis visible on radiographs. Paradoxically, avascular necrosis (9%) is due to small head fractures. The results of our series are compared with the few series that have been published since CT scanning has been systematically used in the ED.