Table 9.

Summary of the results of ACDF compared with Bryan disc using clinical and radiologic parameters

Parameters	Single level ACDF and Bryan		Double level ACDF and Bryan
VAS score	p = 0.8371		p = 0.2938
NDI score	p = 0.2872		p = 0.6753
ROM (implanted level)	p < 0.0001*		p < 0.0001*
ROM (upper adjacent level)	p = 0.2872		p < 0.0001*
ROM (lower adjacent level)	p < 0.005*		p < 0.0001*
FSU alignment	p < 0.0001*		p = 0.0280*
Overall C2–C7 alignment	p < 0.0001*		p < 0.0001*
Disc height(Implanted –AIH)	p < 0.0001*		p < 0.0001*
Disc height(Implanted –PIH)	p = 0.0052*		p < 0.0001*
Disc height(upper–AIH)	p = 0.1264		p = 0.0172*
Disc height(upper–PIH)	p < 0.0001*		p = 0.8363
Disc height(lower–AIH)	p = 0.7598		p < 0.0001*
Disc height(lower–PIH)	p < 0.0001*		p < 0.0001*

p = 0.05 set value for statistical significance using the mixed model

* Statistically significant

AIH Anterior interbody height, PIH posterior interbody height, ACDF anterior cervical discectomy and fusion, FSU functional spinal unit, VAS visual analogue scale, NDI neck disability index