1. Cervical disc arthroplasty for symptomatic cervical disc disease: Traditional and Bayesian meta-analysis with trial sequential analysis 
Shun-Li Kan, Zhi-Fang Yuan, Guang-Zhi Ning, Fei-Fei Liu, Jing-Cheng Sun, Shi-Qing Feng 
International Journal of Surgery 
Volume 35, Pages (November 2016)
DOI: /j.ijsu
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

2. Fig. 1 The flow diagram of study selection.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

3. Fig. 2
Risk of bias assessment of each included study: (a) Risk of bias graph, (b) Risk of bias summary.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

4. Fig. 3
Comparison of overall success in participants undergoing CDA versus ACDF. CDA: cervical disc arthroplasty, ACDF: anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

5. Fig. 4
Trial sequential analysis of five trials comparing CDA with ACDF for overall success. Trial sequential analysis of five trials (black square fill icons) illustrating that the cumulative z-curve crossed both the conventional boundary and the trial sequential monitoring boundary for benefit and the required information size had also been reached, indicating sufficient and conclusive evidence had been ascertained. A diversity adjusted required information size of 2057 patients was calculated using α = 0.01 (two sided), β = 0.10 (power 90%), a relative risk reduction of −28.74% based on trials with adequate allocation concealment, and an event proportion of 55.05% in the control arm. X-axis: the number of patients randomized; Y-axis: the cumulative Z-Score; Horizontal green dotted lines: conventional boundaries (upper for benefit, Z-score = 1.96, lower for harm, Z-score = −1.96, two-sided P = 0.05); Sloping red full lines with black square fill icons: trial sequential monitoring boundaries calculated accordingly; Blue full line with black square fill icons: Z-curve; Vertical red full line: required information size calculated accordingly; CDA: cervical disc arthroplasty; ACDF: anterior cervical discectomy and fusion. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

6. Fig. A.1. Meta-regression analysis of influence of female ratio on overall success. The circles represent each study. The size of the circle represents the power of the study. The solid line indicates the weighted regression line.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

7. Fig. B.1. Meta-regression analysis of influence of the mean age on overall success. The circles represent each study. The size of the circle represents the power of the study. The solid line indicates the weighted regression line.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

8. Fig. C.1. Funnel plot of neck disability index of the included studies comparing cervical disc arthroplasty with anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

9. Fig. D.1. Funnel plot of neck pain of the included studies comparing cervical disc arthroplasty with anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

10. Fig. E.1. Funnel plot of arm pain of the included studies comparing cervical disc arthroplasty with anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

11. Fig. F.1. Funnel plot of secondary surgical procedures of the included studies comparing cervical disc arthroplasty with anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions

12. Fig. G.1. Funnel plot of adverse events of the included studies comparing cervical disc arthroplasty with anterior cervical discectomy and fusion.
International Journal of Surgery  , DOI: ( /j.ijsu )
Copyright © 2016 IJS Publishing Group Ltd Terms and Conditions