The frequency of roentgenographically obvious fractures of the sacrum in association with fractures of the pelvic ring was 45 per cent. in this series of cases.
The varieties and mechanism of sacral fractures are discussed; most of these fractures are caused by leverage through the detached half of the pelvis.
The involvement of the sacrum in this type of fracture is localized around the first and second anterior and posterior foramina.
The roentgenographic features characteristic of this lesion are described.
Disturbance of the fist and second sacral nerve roots produces a readily recognizable syndrome. This syndrome is characterized by sensory disturbances over the outer side of the foot, weakness of the hamstrings and glutei, marked weakness of the calf, and diminution or loss of the ankle jerk.
Recovery is slow, and permanent impairment of gait and limitation of activity may follow.