Table 1 Summary of study characteristics and demographics
Study | Type | Time | Study period | Country | Surgical levels (ZP/CP) | Patients (ZP/CP) | Gender (male/female) | Mean age | Follow-up (months) | Design of zero-profile device | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
ZP | CP | ZP | CP | |||||||||
Nemoto [12] | RCT | 2015 | 2010–2012 | Japan | One, 24/22 | 46 (24/22) | 21/3 | 21/1 | 40.9 ± 7.2 | 41.6 ± 7.0 | 24 | PREVAIL |
Shin [24] | Retro | 2014 | 2008–2013 | Korea | One, 20/20 | 40 (20/20) | 7/13 | 13/7 | 50.0 ± 12.0 | 44.3 ± 9.7 | 13.5 | Zero-P |
Lee [2] | Retro | 2015 | 2005–2011, 2012–2013 | Korea | One, 23/18 | 41 (23/18) | 11/12 | 11/7 | 57.26 ± 13.28 | 52.89 ± 7.71 | 19.9 | Zero-P |
Shi [9] | Retro | 2015 | 2010–2011 | China | Three, 18/20 | 38 (18/20) | 11/7 | 12/8 | 56.2 ± 64.8 | 56.7 ± 63.9 | 30.3 | Zero-P |
Chen [11] | Retro | 2016 | 2010–2012 | China | Three, 18/20 | 71 (33/38) | 18/15 | 21/17 | 49.3 ± 3.7 | 48.8 ± 3.9 | 30.8 | Zero-P |
Li [13] | Retro | 2017 | 2009–2013 | China | One, 32/34; two, 21/23; three, 11/10; four, 4/3 | 138 (68/70) | 41/27 | 45/25 | 50.6 ± 7.5 | 51.3 ± 7.9 | 24 | Fidji |
Yun [25] | Retro | 2017 | 2006–2015 | Korea | Two, 31/32 | 63 (31/32) | 22/9 | 29/3 | 53.29 ± 7.55 | 54.18 ± 9.87 | 13.2 | Zero-P |
Zhou [10] | Retro | 2018 | 2010–2013 | China | One, 20/21; two, 18/14; three, 13/12 | 98 (51/47) | 23/28 | 22/25 | 62.3 ± 6.7 | 64.4 ± 3.2 | 36 | ROI-C |
Lu [23] | Retro | 2018 | 2011–2015 | China | Two, 22/24 | 46 (22/24) | 13/9 | 15/9 | 56.6 ± 6.4 | 58.6 ± 7.2 | 24 | ROI-C |
Zhu [26] | Retro | 2019 | 2013–2014 | China | Three, 30/32 | 62 (30/32) | 12/18 | 18/14 | 56.6 ± 12.6 | 55.3 ± 11.3 | 36 | MC+ |