Table 2

Study characteristics

SourceYear publishedStudy designSample size (n)Mean age at ACLR (years)Age variance (years, SD or range)*Follow-up time (months, mean±SD or median* (range))Activity level (Tegner or Marx)Return-to-sport percentage (%)Second ACL injuries (total)Second ACL injuries (females)Second ACL injuries (males)
Bak et al†‡60 2001CS13223.016–39*47* (24–92)9671331
Beischer et al61 2020PC15921.54.415.5* (4–46.5)8.56418117
Bourke et al62 2012CS67329.19.216.8* (15–18.9)7315648108
Cordasco et al 53 2017CS2312.29.9–14.5*32.1* (24–45)13.4¶95.7101
Dekker et al63 2017RC8513.92.148.3±15.313.7¶91271413
Demange et al 54 2014CS1210.78.3–12.4*220* (180–264)83.3312
Everhart et al64 2019RC36024.18.4>2499271017
Fleming et al 55 2013RCT8523.52.5367.6100752
Geffroy et al**56 2018PC27813.52.1>24777291013
Graziano et al 57 2017CS4212.010–15*>2423.2¶95.2624
Gupta et al 58 2019RC34026.05.5>248.510025421
Heath et al65 2019CS24714.68–17.9*54* (24–147)59.1812556
Heijne et al†††66 2015PC6829.58.161.5* (60–84)71001192
Kamath et al67 2014CS89>18N/A4892.920119
Laboute et al 59 2010RC29826.07.742* (36–48)8626521
Mohtadi et al68 2016RCT32228.59.8>247.783964353
Paterno et al30 2014PC7817.13.1>2410023194
Shelbourne et al38 2009PC40215.61.0117.6±62.491001048123
Webster et al69 2019RC32917.22.060 (36–108)100953659
  • *Median values.

  • †Included in primary meta-analysis.

  • ‡Bak et al reported 9 contralateral ACL injuries that were not categorised by sex.

  • §Interpreted Tegner based on qualitative data.

  • ¶Marx activity level.

  • **Geffroy et al reported 6 contralateral injuries that were not categorised by sex.

  • ††Heijne et al reported two participants (1 male, 1 female) that experienced both an ipsilateral and contralateral ACL injury but did not report which occurred first, both injuries are included.

  • ACLR, ACL reconstruction; CS, case series; PC, prospective cohort; RC, retrospective cohort; RCT, randomised control trial.