Summary
Spinal fractures are common in the thoracolumbar region. Assessment of fracture instability is often made from fracture patterns seen on plain radiographs or CT scans. The purpose of this in vitro study was to correlate three-dimensional flexibility to each fracture type, i.e., endplate, wedge, and brust. Ten fresh cadaveric human spine specimens (T11-L1) were incrementally impacted in a high-speed trauma apparatus until a fracture occurred. All fractures were produced by the same mechanism (axial compression/flexion load). The occurrence of a fracture was monitored by lateral radiographs of the specimen, whose canal was lined with 1.6-mm steel balls. After each impact, the specimen was studied for its flexibilily in flexion, extension, left and right lateral bindings, and left and right axial rotations. The flexibility was determined in response to the application of maximum pure moments of 7.5 Nm. Each moment was applied individually and in three load cycles. Parameters of neutral zone (NZ) and range of motion (ROM) were computed. Average flexion-extension ROM (and NZ) for intact, endplate, wedge, and burst fracture were respectively, 12.7° (1.3°), 13.9° (1.7°), 19.2° (3.2°), 22.0° (6.0°). The average lateral bending ROM (NZ) were 12.6° (1.2°), 13.6° (1.9°), 19.1° (3.7°), 27.2° (9.8°). The average axial rotation ROM (NZ) were 4.7° (0.4°), 6.1° (0.7°), 7.1° (1.0°), 12.9° (3.1°). The highest instability (fracture/intact motion) was seen in the axial rotation NZ in all three fracture types: 3.2, 5.4, and 14.7, respectively, for the endplate, wedge, and brust fractures. The average kinetic energy and force necessary to produce endplate, wedge, and burst fractures were 57, 84, 104 Nm, and 4.8, 6.5, 6.3 kN, respectively.
Similar content being viewed by others
References
Brown T, Hanson R, Yorra A (1957) Some mechanical tests on the lumbosacral spine with particular reference to the inter vertebral diso. J Bone Joint Surg [Am] 39:1135–1164
Ciccone R, Richman RM (1948) The mechanism of injury and the distribution of three thousand fractures and dislocations caused by parachute jumping. J Bone Joint Surg 30:77–97
Denis F (1983) The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine 8:817–831
Dorr LD, Harvey JP JR, Nickel VL (1982) Clinical review of the early stability of spine injuries. Spine 7:545–550
Ferguson RL, Allen BL Jr (1984) A mechanistic classification of thoracolumbar spine fractures. Clin Orthop 189:77–88
Fredrickson BE, Mann KA, Yuan HA, Lubicky JP (1988) Reduction of the intracanal fragment in experimental burst fractures. Spine 13:267–271
Gertzbien SD, Eismont FJ (1990) Trauma of the lumbar spine: classification and treatment. In: Weinstein JN, Wiesel SW (eds) The lumbar spine. Sanders, Philadelphia, pp 662–698
Göcke C (1928) Beitraege zur Druckfestigkeit des spongiösen Knochens. Beitr Klin Chir 143:539
Holdsworth FW (1970) Fractures, dislocations, and fracturedislocations of the spine. J Bone Joint Surg [Am] 52:1534–1551
Holmes AD, Hukins DWL, Freemont AJ (1993) End-plate displacement during compression of lumbar vertebra-disc-vertebra segments and the mechanism of failure. Spine 18:128–135
Jacobs RR, Asher MA, Snider RK (1980) Thoracolumbar spinal injuries. A comparative study of recumbent and operative treatment in 100 patients. Spine 5:463–477
Magerl F (1985) Der Wirbel-Fixateur Externe. In: Weber BG, Magerl F (eds) Fixateur Externe. Springer, Berlin Heidelberg New York, pp 291–297
McAfee PC, Yuan HA, Lasda NA (1982) The unstable burst fracture. Spine 7:365–373
McAfee PC, Yuan HA, Frederickson BE, Lubicky J (1983) The value of computed tomography in thoracolumbar fractures. J Bone Joint Surg [Am] 65:461–473
Meyer PR (1989) Surgery of spine trauma. Churchill Livingstone, New York
Nicoll EA (1949) Fractures of the dorso-lumbar spine. J Bone Joint Surg [Br] 31:376–394
Oxland TR (1992) Burst fractures of the human thoracolumbar spine: a biomechanical investigation. Ph D Dissertation, Yale University, New Haven
Oxland TR, Panjabi MM (1992) The onset and progression of spinal injury: a demonstration of neutral zone sensitivity. J Biomech 25:1165–1172
Panjabi MM, Duranceau JS, Oxland TR, Bowen CE (1989) Multidirectional instabilities of traumatic cervical spine injuries in a porcine model. Spine 14:1111–1115
Perey O (1957) Fracture of the vertebral end-plate in the lumbar spine. Acta Orthop Scand 25 (Suppl)
Rauber AA (1876) Elasticität und Festigkeit der Knochen. W. Engelmann, Leipzig
Trafton PG (1984) Computed tomography of thoracic and lumbar spine injuries. J Trauma 24:506–515
Willen J, Lindahl S, Irstram L, Aldman B, Norwall A (1984) The thoracolumbar crash fracture — an experimental study on instant axial dynamic loading: the resulting fracture type and its instability. Spine 9:624–630
Wolter D (1985) Vorschlag für eine Einteilung von Wirbelsäulenverletzungen. Unfallchirurg 88:481–484
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kifune, M., Panjabi, M.M., Arand, M. et al. Fracture pattern and instability of thoracolumbar injuries. Eur Spine J 4, 98–103 (1995). https://doi.org/10.1007/BF00278920
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00278920