Pathoanatomic Risk Factors for Instability and Adjacent Segment Disease in Lumbar Spine: How to Use Topping Off?

Table 1

Overview of pedicle-based study methods.

Author	Implant	Subject number	Follow-up (months)	Publication year	Level of evidence	Study design
Kim et al. [12]	Bioflex	46	9	2007	2b	Retrospective
Ogawa et al. [13]	Sublaminar wiring	54	40	2009	1b	Prospective
Kaner et al. [14]	Agile topping off	15	19	2009	1b	Prospective
Putzier et al. [15]	Dynesys transition	22	76	2010	1b	Randomized
Schwarzenbach et al. [16]	Dynesys	31	39	2010	3b	Retrospective
Maserati et al. [17]	Dynesys to Optima	22	(1–22)	2010	2b	Retrospective
Hudson et al. [18]	IsoBar	22	24	2011	1b	Prospective
Kumar et al. [19]	Dynesys	32	24	2012	1b	Prospective
Coe et al. [20]	NFlex	40	24	2012	2b	Retrospective
Zagra et al. [21]	FlexPlus	32	12	2012	1b	Prospective
Li et al. [22]	IsoBar	36	24	2013	2b	Retrospective
Fu et al. [23]	IsoBar	36	24	2014	1b	Retrospective