Lumbar disc rehydration in the bridged segment using the BioFlex dynamic stabilization system: A case report and literature review

Table 1 Related research to evaluate the potential mutual relationship between dynamic stabilization systems and disc rehydration

Ref.	Types of implants	Age in yr	Number of patients	Follow-up in mo	Proportion of disc rehydration	Assessment method	Main findings	Comments
Bordes-Monmeneu et al[15], 2005	Dynesys	46.4 (26-68)	20	9	9/20 (45%)	MRI, signal intensity	Disc rehydration occurred in some patients	Retrospective study, case series
Vaga et al[14], 2009	Dynesys	43.5 ± 9	10	6	3/10 (30%)	Molecular MRI, Pfirrmann grading	The Dynesys was able to stop and partially reverse the disc degeneration, especially in seriously degenerated disc and Pfirrmann grading was not sensitive enough to detect the disc change	Prospective study
Cho et al[13], 2010	BioFlex	22	1	12	1/1 (100%)	MRI, signal intensity	Increased disc height and disc rehydration occurred after BioFlex system	Case report
Reyes-Sánchez et al[12], 2010	Accuflex	44.05 (24-60)	20	24	3/18 (16.67%) 2 cases lost follow	MRI, Pfirrmann grading	Three patients showed disc rehydration with one grade higher on the Pfirrmann classification and the Accuflex system stopped the degenerative process in 83% the patients	Prospective study, consecutive case series
Sandu et al[11], 2011	Wallis	67 (39-79)	15	12	NA	MRI, Modic grading	Wallis implantation could lead to disc rehydration	Retrospective study, case series
Heo et al[9], 2012	BioFlex	59.0 ± 8.4	25	> 24	2/13 (15.4%) Exclude discectomy cases	MRI, modified Pfirrmann grading	BioFlex system might not prevent adjacent level degeneration completely. However, disc rehydration of the implantation segment occurred in 2 patients	Prospective study, case series
Xu et al[10], 2012	Wallis	41.5 (21-68)	96	28 ± 14	NA	MRI, signal intensity	Disc rehydration of the implantation segment occurred in some patients	Retrospective study, case series
Zagra et al[8], 2012	FPSS system	51.65 (25-65)	32	12	8/32 (25%)	MRI, Pfirrmann grading	FPSS system was able to provide a potential disc rehydration	Prospective study, case series
Fay et al[7], 2013	Dynesys	53.0 ± 9.0	37	> 48	NA	MRI, CDS	Intervertebral disc rehydration was seen in younger patients and the Dynesys might stop or reverse the disc degeneration in the young age patients but not for the elderly patients	Retrospective study, case series
Gao et al[6], 2014	ISOBAR TTL	58.3 ± 13.5	24	28.7 ± 5.3	14/24 (58.33%)	MRI, Pfirrmann grading, ADC	ISOBAR TTL system could prevent or delay the degeneration of intervertebral discs	Retrospective study, comparative study
Canbay et al[5], 2015	cosmicMIA	38.7 ± 8.39	27	49.3 ± 18.35	4/27 (14.8%)	MRI, Pfirrmann grading, HIZ	Observations such as Pfirrmann grade improvements and disappearance of HIZs are concordant with improvements in VAS and ODI scores demonstrated that cosmicMIA systems might provide an environment for regeneration	Retrospective study, case series
Jiang et al[4], 2015	Wallis	47.6 (43-56)	26	66.8 (60-70)	NA	MRI, Pfirrmann grading	Rehydration of the nucleus was observed, however, there were no statistically significant changes in the Pfirrmann grade at the instrumented level	Retrospective study, case series
Yilmaz et al[3], 2017	Cosmic, Safinaz	46.5 (27-67)	59	86.8 (12-132)	20/59 (34%)	MRI, Pfirrmann grading	DSS might decelerate the degeneration process and appears to facilitate regeneration	Retrospective study, case series
Luo et al[16], 2018	Dynesys	40.6 (21-55)	23	39 (26-59)	6/13 (46.2%)	MRI, Woodend classification	Dynamic stabilization promoted disc regeneration to some extent	Retrospective study, case series
Li et al1	BioFlex	54	1	24	1/1 (100%)	MRI, signal intensity	Decreased disc height and disc rehydration occurred after BioFlex system	Case report

¹The present study. MRI: Magnetic resonance imaging; NA: Not available; CDS: Calibrated disc signal; ADC: Apparent diffusion coefficient; HIZ: High-intensity zone; VAS: Visual analog scale; ODI: Oswestry disability index; DSS: Dynamic stabilization system.