Table 1 Characteristics of included studies
Authors | Year | Study type | Age (years) | Male | Surgical procedure | Follow-up | N (ASD) | N (Controls) |
|---|---|---|---|---|---|---|---|---|
Katsuura et al. [16] | 2001 | Retrospective study | 48.1 for ASD and 52.7 for Control | 19/21 for ASD and 15/21 for Control | ACDF | 122.4 months for ASD and 112.7 months for Control | 21 | 21 |
Kim et al. [17] | 2015 | Prospective study | 43.52 | 117/180 | TDR | Mean 48.6 months | 73 | 107 |
Lee et al. [18] | 2015 | Retrospective study | 47.1 | 12/14 | CDA | Mean 43.4 months | 5 | 9 |
Retrospective study | 53.6 | 24/28 | ACDF | Mean 44.6 months | 16 | 12 | ||
Li et al. [19] | 2015 | Retrospective study | 50.2 | 61/106 | ACDF | 30.6 months for ASD and 31.2 months for non-ASD | 28 | 88 |
Song et al. [20] | 2018 | Retrospective study | 51.8 for ASD and 48.5 for N-ASD | 11/25 for ASD and 85/175 for N-ASD | ACCF and ACDF | 34.2 months for ASD and 34.8 months for N-ASD | 25 | 175 |
Song et al. [21] | 2014 | Retrospective study | 57.73 for ASD and 54.09 for Control | 12/15 for ASD and 125/216 for Control | ACDF | Mean 63.85 months | 15 | 216 |
Yang et al. [22] | 2017 | Retrospective study | 43.3 for ASD and 42.6 for N-ASD | 17/21 for ASD and 25/27 for N-ASD | CDA | Mean 79.3 months for SASD and 78.6 months Non-SASD | 38 | 52 |