Factors that influence long term instrumentation stability in patients with unstable thoracolumbar injuries

Table 3 Parameters of general discriminant model for the assessment of risk factors for clinically significant instrumentation failure

Components of regression equation	Regression coefficient	Statistical significance	Beta coefficient
Intercept	0.5679	P = 0.0008	-
Residual deformity of over 10°	0.0529	P = 0.0518	0.1216
Anterior fusion bipolar, Tan 1-2	0.0027	P = 0.9323	0.0063
Partial or complete ankyloses of facet joints within instrumented area	-0.1684	P = 0.0006	-0.4612
Anterior decompression performed	0.0219	0.5109	0.0463
Anterior reconstruction	-0.0780	0.0040	0.0207
Extensive posterior decompression with laminectomy and at least one level total facetectomy	0.1194	P = 0.0003	0.2716
Lumbosacral fusion	0.0799	0.2133	0.0796
Radiodensity in HU	0.0002	0.6894	0.0239
Length of fixation (number of levels)	0.0362	0.6894	0.0239
Intermediate fixation	-0.1262	0.0025	-0.2036

HU: Hounsfield units.