The Strength of the Osteoporotic Sacrum
| Autor: | Matthew D. Waites, Stephen M. Belkoff, John M. Mathis, Simon C. Mears |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Male
musculoskeletal diseases Sacrum Compressive Strength Symphysis Osteoporosis Weight-Bearing Ala of sacrum medicine Insufficiency fracture Humans Orthopedics and Sports Medicine Orthodontics business.industry musculoskeletal system medicine.disease Sagittal plane Biomechanical Phenomena body regions Fractures Spontaneous medicine.anatomical_structure Fracture (geology) Spinal Fractures Female Neurology (clinical) Cadaveric spasm business |
| Zdroj: | Spine. 32:E652-E655 |
| ISSN: | 0362-2436 |
| DOI: | 10.1097/brs.0b013e318158c552 |
| Popis: | STUDY DESIGN Biomechanical cadaveric bench study. OBJECTIVE To determine the strength of the osteoporotic sacrum subjected to vertical force. SUMMARY OF BACKGROUND DATA Sacral insufficiency fractures are thought to be caused by vertical shear forces acting in the sacral ala. The force required to fracture the osteoporotic sacrum is unknown. METHODS Eighteen osteoporotic cadaveric pelves were potted and mounted on a materials testing machine so that the anterior superior spine was aligned with the symphysis in the sagittal plane. The lumbar spine (L3-L4) was displaced vertically downward until failure occurred. Failure loads were recorded, and fracture patterns were identified via computed tomography. RESULTS Mean (+/-SD) failure load was 3200 +/- 1262 N. In 3 of 18 specimens, sacral fractures were not apparent on computed tomography. In 15 of 18 specimens, fractures were produced lateral to the neural foramina. Of those 15 specimens, 8 were unilateral (1 with horizontal extension) and 7 were bilateral. In 13 of 15 cases, fractures were located in Denis Zone 1. CONCLUSION The osteoporotic sacrum failed under vertical forces of approximately 4.5 times body weight. Imaged fracture patterns resembled sacral insufficiency fractures seen clinically. In 1 case, a horizontal fracture line was produced. Vertical compression forces appear to cause insufficiency fractures in the osteoporotic sacrum. |
| Databáze: | OpenAIRE |
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