Table 1.
Characteristics of the studies included in the meta-analysis
| Article | Study design | Participants (n) | Age mean (sd/range) | Activity level /sports participation | Risk factor(s) | Follow-up (mean/range, years) | Number of C-ACL injuries (n) | Quality score |
|---|---|---|---|---|---|---|---|---|
| Adults and pediatrics | ||||||||
| Allen et al. [51] | Retrospective | 180 females | 19.6 (6.9) | Tegner score: 7.9 (0.7) at primary injury | Playing soccer, RTS | 5.7 | 19 | 17/19 = 89% |
| Annear et al. [36] | Prospective RCT | 19 females, 23 males | 28.9 (10.6) | NA | Age, sex, associated injuries | 10 | 5 | 11/19 = 58% |
| Bourke et al. [52] | Retrospective | 241 females, 432 males | 29 (13–62) | NA | Age, sex, family history, associated injuries, RTS | 16 | 95 | 15/19 = 79% |
| Filbay et al. [32] | Prospective | 32 females, 86 males | 26 (5) | Moderate-high activity level (non professional) at primary injury | Age, BMI, associated injuries, activity level, smoking status | 5 | 5 | 17/19 = 89% |
| Fältström et al. [10] | Retrospective | 107 females, 140 males | 28.5 (8.2) | Tegner activity level 9 at primary injury | Activity level | NA | 66 | 10/19 = 53% |
| Fältström et al. [45] | Retrospective | 8986 females, 11,838 males |
No further injury: 27 (9.9) C-ACL injury: 22.3 (8.4) |
Soccer, other contact ball sports, other sport/recreation, other causes (causes of injury) | Age, sex, associated injuries, playing soccer, timing of surgery | 0.5–8.6 | 591 | 17/19 = 89% |
| Goshima et al. [54] | Retrospective | 160 females, 73 males | 21 (14–51) | Tegner score: 7 (0.8) (Time point NA) | Family history | 2 | 29 | 14/19 = 74% |
| Grassi et al. [8] | Retrospective | 47 females, 147 males | 30.7 (10.6) |
Pre-operative Tegner score ≥ 7: 44% < 7: 56% |
Age, Sex, BMI, smoking, timing of surgery | 10 | 19 | 15/19 = 79% |
| Kaeding et al. [56] | Prospective | 1123 females, 1365 men | 27 (11) | Marx score: 11.3 (5.3) at primary injury | Age, sex, associated injuries, RTS | 2 | 88 | 15/19 = 79% |
| Leys et al. [60] | Prospective | 85 females, 95 males | 24.5 (13–52) | 81% participated in moderate-to-streneous activity at primary injury | Age, sex | 15 | 34 | 15/19 = 79% |
| Maletis et al. [62] | Retrospective | 6277 females, 11,159 males | 27.2 (IR: 18.7–37-7) | NA | Age, sex, BMI | 2.4 | 324 | 15/19 = 79% |
| Mardani-Kivi et al. [63] | Retrospective | 179 females, 836 males | 34 (8.9) | Sport inactivity – regular sport activity (Time point NA) | Sex, BMI, family history | 6.5 | 83 | 14/19 = 74% |
| McPherson et al. [34] | Prospective | 118 females, 211 males | 25.3 (8.7) | Sports participation at primary injury | Sex | 2 | 18 | 15/19 = 79% |
| Mohtadi et al. [64] | Prospective RCT | 147 females, 183 males | 28.5 (9.8) | Tegner Score ≥ 5 at primary injury | Sex | 2 | 17 | 16/19 = 84% |
| Nakase et al. [66] | Retrospective Case–control | 174 females, 50 males | No injury: 19.3 (4.4) C-ACL injury; 17.5 (4) |
Tegner score No injury: 7.0 (0.7) C-ACL: 7.2 (0.8) (Time point NA) |
Age | NA | 24 | 13/19 = 68% |
| Paterno et al. [47] | Prospective | 59 females, 19 males | 17.1 (3.1) | IKDC Level 1–2 at primary injury | Sex | 2 (after RTS) | 16 | 13/19 = 68% |
| Pinczewski et al. [71] | Prospective | 85 females, 95 males | 25 (13–42) | Pivoting, cutting or side-stepping sports at primary injury | Sex | 10 | 29 | 14/19 = 74% |
| Pujol et al. [72] | Prospective | 53 females, 52 males | Females: 17 (2) Males: 18 (2.1) | Alpine Skiers at primary injury | Sex | 26 | 23 | 14/19 = 74% |
| Rosenstiel et al. [73] | Retrospective | 22 females, 48 males | 23.2 (15–37) | Tegner score: 9.3 (1) at primary injury | Sex | 3.9 | 10 | 15/19 = 79% |
| Salmon et al. [75] | Prospective | 74 females, 105 males | 25.8 | Streneous, moderate or light activity at follow-up | Age, sex, family history | 19.7 | 22 | 14/19 = 74% |
| Salmon et al. [76] | Prospective | 67 20 Females47 males | 27 | Pivoting, cutting or side-stepping sports at primary injury | Age, sex | 13 | 15 | 15/19 = 79% |
| Salmon et al. [74] | Prospective | 289 females, 383 males | 28 (14–62) | IKDC level 1–4 at primary injury | Sex, family history, associated injuries, RTS | 5 | 35 | 15/19 = 79% |
| Schickendantz et al. [77] | Retrospective | 29 unilateral, 19 bilateral (females/males NA) | 23.5 | NA | Geometrics | NA | 24 | 11/19 = 58% |
| Shelbourne et al. [80] | Prospective | 552 females, 863 males | 21.6 (3.6) | Tegner score: > 7 at primary injury | Sex, age, timing of RTS | 5 | 75 | 14/19 = 74% |
| Shelbourne et al. [79] | Prospective | 234 women, 480 men | 24.3 | Noyes score: 99.7% > 12 at primary injury | Sex | NA | 27 | 17/1 9 = 89% |
| Souryal et al. [81] | Retrospective | 50 unilateral, 41 C-ACL (females/males NA) | 19 (13–38) | 89% participated in sports at primary injury | Geometrics | 4 | 41 | 10/19 = 53% |
| Sousa et al. [82] | Prospective | 131 females, 92 males | 22 (12–59) | Tegner score: > 6.5 at primary injury | Timing of RTS | 4 | 17 | 17/19 = 89% |
| Thompson et al. [42] | Prospective | 44 females, 46 men | 25 (15–42) | Pivoting, cutting or side-stepping sports at primary injury | Age, sex, family history | 20 | 27 | 15/19 = 79% |
| Wasserstein et al. [83] | Retrospective | 4708 females, 8259 males | 29.5 (10.5) | NA | Age, sex, associated injuries | 5.2 | 595 | 16/19 = 84% |
| Webster et al. [49] | Retrospective | 191 females, 370 males | 28.5 (9.9) | NA | Age, sex, family history, RTS | 4.8 | 42 | 16/19 = 84% |
| Wright et al. [84] | Prospective | 110 females, 125 males | 24 (11–54) | NA | Sex | 2 | 7 | 12/19 = 63% |
| Pediatrics only | ||||||||
| Heath et al. [55] | Prospective | 82 females, 166 males | 14.6 (8–17.9) | > 86% participated in sports at primary injury | Age, sex, family history | 4.5 | 28 | 15/19 = 79% |
| Morgan et al. [65] | Prospective | 104 females, 138 males | 13–18 | > 91% participated in sports at primary injury | Age, sex, family history, RTS | 16.5 | 48 | 14/19 = 74% |
| Perkins et al. [69] | Retrospective | 197 females, 157 males | 15.3 (10–19) | NA | Sex | 2 | 24 | 15/19 = 79% |
| Schmale et al. [78] | Retrospective | 23 females, 6 males | 14 (1.0) | Tegner score: 8 at primary injury | Sex | 4 | 8 | 13/19 = 68% |
C-ACL contralateral, NA not available, RTS return to sport