Validity of the three-column theory of thoracolumbar fractures. A biomechanic investigation.
METHODS
This study validated the three-column theory of fractures by correlating the multidirectional instabilities and the vertebral injuries to each of the three columns, using a biomechanic trauma model.


OBJECTIVE
The objective was to validate the three-column theory as applied to the thoracolumbar fractures.


BACKGROUND
The widely used three-column theory of fractures for classification and evaluation was based on retrospective analysis of radiographs. No biomechanic study, using realistic spinal fractures and multidirectional instability measurements, was available.


METHODS
Using 16 fresh cadaveric thoracolumbar human spine specimens, two groups of burst fractures were produced by either simple axial compression or flexion-compression, using a high-speed trauma model. Multidirectional flexibility was measured before and after the trauma, thus quantifying the instability of the burst fracture. Computed tomography scans were taken after the fracture, and a newly developed injury scoring scheme quantified the injuries to the anterior, middle, and posterior columns. Statistical correlations were obtained between the flexibility parameters and injuries to each of the three columns.


RESULTS
In the axial compression group, the middle column injury, compared with the other two columns, showed the highest correlations to eight of the nine flexibility parameters (average R2 = 0.77). In the flexion-compression group, again the middle column injury showed the highest correlations to eight of the nine flexibility parameters (average R2 = 0.85).


CONCLUSIONS
The results of this study supported the three-column theory of the thoracolumbar fractures and bolstered the concept of the middle column being the primary determinant of mechanical stability of this region of the spine.
Panjabi
M M
MM
Department of Orthopaedics & Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA.
Oxland
T R
TR
Kifune
M
M
Arand
M
M
Wen
L
L
Chen
A
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D015601:Injury Severity Score; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D008297:Male; D008875:Middle Aged; D016103:Spinal Fractures / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D014057:Tomography, X-Ray Computed