Table 1. Study characteristics.
| Follow up duration | First author (year) | ACDA product | Study type | Study country | ACDA (n) | ACDF (n) | Mean follow-up time (mo) |
|---|---|---|---|---|---|---|---|
| Short-term (FU 12 mo < x < 24 mo) | Hou et al. (2014) (18) | Discover | RCT | China | 117 | 108 | 24 |
| Li et al. (2014) (19) | Scient-X | Prospective CT | China | 39 | 42 | 24 | |
| Tracey et al. (2014) (20) | Prestige | Retrospective | USA | 171 | 88 | 12 | |
| Rožanković et al. (2014) (21) | Discover | RCT | Croatia | 51 | 50 | 24 | |
| Kang et al. (2013) (22) | ProDisc-C | RCT | China | 12 | 12 | 33 | |
| Zhang et al. (2012) (23) | Bryan | RCT, M | China | 60 | 60 | 24 | |
| Auerbach et al. (2011) (24) | ProDisc-C | Prospective | USA | 93 | 94 | 24 | |
| Coric et al. (2011) (8) | Kineflex-C | RCT, M | USA | 136 | 133 | 24 | |
| Hisey et al. (2011) (25) | Mobi-C | RCT, M | USA | 164 | 81 | 24 | |
| Kelly et al. (2011) (26) | ProDisc-C | RCT | USA | 100 | 99 | 24 | |
| Park et al. (2011) (27) | PCM | RCT, M | USA | 272 | 182 | 12 | |
| Anakwenze et al. (2009) (28) | ProDisc-C | RCT | USA | 89 | 91 | 24 | |
| Cheng et al. (2009) (29) | Bryan | RCT | China | 31 | 34 | 24 | |
| Heller et al. (2009) (30) | Bryan | RCT, M | USA | 242 | 221 | 24 | |
| Kim et al. (2009) (31) | Bryan | RCT | Korea | 51 | 39 | 19 | |
| Anderson et al. (2008) (32) | Bryan | RCT, M | USA | 242 | 221 | 24 | |
| Peng-Fei et al. (2008) (33) | NR | RCT | China | 12 | 12 | 17 | |
| Sasso et al. (2008) (34) | Bryan | RCT, M | USA | 242 | 221 | 24 | |
| Mummaneni et al. (2007) (10) | Prestige | RCT, M | USA | 276 | 265 | 24 | |
| Nabhan et al. (2007) (35) | ProDisc-C | RCT | Germany | 16 | 17 | 6 | |
| Long-term (>24 mo) | Davis et al. (2015) (9) | Mobi-C | RCT, M | USA | 225 | 105 | 48 |
| Burkus et al. (2014) (36) | Prestige | RCT, M | USA | 276 | 265 | 84 | |
| Coric et al. (2013) (37) | Bryan/Kineflex-C | RCT | USA | 41 | 38 | 72 | |
| Zigler et al. (2012) (38) | ProDisc-C | RCT, M | USA | 103 | 106 | 60 | |
| Sasso et al. (2011) (39) | Bryan | RCT, M | USA | 242 | 221 | 48 | |
| Burkus et al. (2010) (40) | Prestige | RCT, M | USA | 144 | 127 | 60 | |
| Delamarter et al. (2010) (41) | ProDisc-C | RCT, M | USA | 103 | 106 | 48 | |
| Garrido et al. (2010) (42) | Bryan | RCT | USA | 21 | 26 | 48 |
ACDA, anterior cervical disc arthroplasty; ACDF, anterior cervical discectomy and fusion; RCT, randomised controlled trial; M, Multi-centre; FU, follow up; mo, month.