[Fractures of the sacrum caused by bone insufficiency. Meta-analysis of 508 cases].

OBJECTIVES: Fractures of the sacrum due to bone deficiency are not extremely uncommon although this cause has been overlooked for many years. We performed a meta-analysis of reported cases in order to determine the specific characteristics.

METHOD: The characteristics of 493 cases of sacral fractures reported in the literature and those of 15 personal cases were studied.

RESULTS: Most of the fractures occurred in women over 60 years of age. No trauma was identified in two-thirds of the cases. Clinical expression was not specific (back pain, sciatica, pelvic pain). Standard x-ray showed a fracture of the obturator frame in 38.8% of the cases but no direct or indirect signs of sacral fracture were seen in more than two-thirds of the cases. Tc99m scintigraphy had excellent sensitivity; a characteristic hyperfixation pattern for ming an "H" was observed but only in 42.7% of the cases. Computed tomography had similar sensitivity and confirmed the diagnosis in doubtful cases. Treatment was usually bed rest until satisfactory pain relief. Of particular importance were neurological complications although they were exceptional. Several factors favoring sacral fracture were found, mainly osteoporosis and prior radiotherapy of the pelvis.

CONCLUSION: Clinicians should be aware of this type of fracture which still remains largely over-looked in geriatric care units.