U FRACTURES OF THE SACRUM: NINE CASES

Abstract

Purpose of the study: Transversal or «U» fractures of the sacrum are rare. Reported for the first time by Bonin in 1945, such fractures concern less than 1% of spinal fractures. Initially, these injuries were often missed despite their association with neurological disorders such as caudia equina syndrome. This late diagnosis is related to the context of multiple trauma and also to insufficient knowledge of this type of injury. The purpose of this study was to draw clinicians’ attention to this type of injury in order to favor early diagnosis and appropriate treatment.

Material and methods: This series included nine cases observed from 1999 to 2002. Mean age was 32 years, range 17–80. Female gender predominated (two-thirds of the patients). Six patients were fall victims, (suicide attempts or scaffold accidents). For eight patients, neurological signs involved a complete S1 or S2 caudia equina syndrome. L5 paralysis was noted in one patient due to a far-out syndrome. The diagnosis was established late in four patients, 2 to 45 days after trauma. Surgical treatment was instituted for six patients with neurological disorders diagnosed early. Treatment consisted in fracture reduction, posterior decompression and posterolateral stabilization. Intraoperative exploration revealed caudia equina contusion and compression in five of six patients with no loss of continuity. The sixth patient presented nearly complete root section.

Results: Eight of the nine patients were followed and reviewed at 2 years 4 months on average. The patient with a root section committed suicide four months postoperatively. Neurological recovery was complete for the five other patients who underwent surgery. Motor, sensorial and sphincter function and the urodynamic study were normal at last follow-up. L5 paralysis recovered last. For the two non-operated patients, only one achieved partial recovery.

Discussion: U fracture of the sacrum is a triple plane fracture which is difficult to explore with plain x-rays. In the context of a multiple trauma victim or attempted suicide, neurological complications are difficult to detect, further retarding the diagnosis of fracture. Roy Camille, Coutallier, Hessman report frequent misdiagnosis of the initial fracture and emphasize the contribution of computed tomography for correcting the diagnosis and establishing the surgical strategy. Surgery is the best option for improving prognosis, both in terms of neurological recovery and lumbopelvic stability.

Conclusion: Emergency physicians, neurosurgeons and orthopedist should be aware of U fractures of the sacrum, particularly in high-energy fall victims. A better clinical approach, particularly systematic examination of the perineum, is the key to successful diagnosis and proper orientation of the x-ray work-up to establish a positive diagnosis and improve the therapeutic approach.