Table 1 Summary of study criteria—prospective studies and retrospective studies
Study | Study type | Sample size | Av. age | Mean duration of follow-up (months) | Gender (M/F) | Level |
|---|---|---|---|---|---|---|
Hermantin et al. [20] | RCT | 60 | 39 vs. 40 | 31(19–42) vs. 32(21–42) | 22:8/17:13 | L2-L3L3-L4L4-L5L5-S1 |
Mayer and Brock [21] | RCT | 40 | 39.8 ± 10.4 vs. 42.7 ± 10 | 6.9 | 12:8/14:6 | L2-L3L3-L4L4-L5 |
Ruetten et al. [10] | RCT | 129 | 43 | 24 | – | L1-L2L2-L3L3-L4L4-L5L5-S1 |
Gibson et al. [22] | RCT | 140 | 42.0 ± 9 vs. 39 ± 9 | 24 | 30:40/40:30 | L3-L4L4-L5L5-S1 |
Akçakaya et al. [27] | RCT | 30 | 44.1 | – | – | – |
Kim et al. [23] | Retro | 902 | 34.9 vs. 44.4 | 23.6 | 188:107/392:215 | L1-L2L2-L3L3-L4L4-L5L5-S1 |
Lee et al. [24] | Retro | 60 | 39.3 vs. 39.6 | 38.2(32–45) vs. 36.8(35–42) | 22: 8/22: 8 | L4-L5L5-S1 |
Ahn et al. [25] | Retro | 66 | 22.41 ± 1.68 vs. 22.18 ± 1.51 | 13.69 + 1.26 vs. 13.41 + 1.02 | 32:0/34:0 | L4-L5 |
Hsu et al. [26] | Retro | 100 | – | 20.4 | – | L1-L2L2-L3L3-L4L4-L5 |