Table 1 Included studies’ characteristics separated by theme. All the conclusions described on the table are based on a p value < 0.05

 Yasuda et al. [11] (1997)

Clinical trial

70

Initial relative high stress in the graft (about 80 N) decreases laxity

 Bylski-Austrow et al. [12] (1990)

Experimental (biomechanical)

6

Stress magnitude is less influencing than fixation angle; there is no correct position or tension

 Gertel et al. [14] (1993)

Experimental (biomechanical)

10

Graft strength and joint mobility unchanged by tension magnitude

 Sherman et al. [1] (2012)

Review article

69

20–80 N of tension is recommended, depending on the graft, if flexion of 30°; 90 N of tension if in extension

 Brady et al. [15] (2006)

Experimental (biomechanical)

12

Tension in extension generated greater compressive forces in the knee (90 N in extension = 3.5 x normal)

 Austin et al. [16] (2007)

Experimental (biomechanical)

10

Graft tension did not change knee extension

 Kim et al. [17] (2018)

Clinical trial

60

It is most appropriate to maintain a 20 -lb. (90 N) tension for graft fixation

 Noyes et al. [18] (2019)

Experimental (biomechanical)

Current tensioning protocols are insufficient; suggests 40 flexion-extension cycles at 90 N for proper graft conditioning

 Debandi et al. [5] (2016)

Experimental (biomechanical)

12

Anatomical reconstruction with fixation at 30° of knee flexion was superior (rotational stability)

 Bylski-Austrow et al. [12] (1990)

Experimental (biomechanical)

6

Tension at 30° leads to greater stress in the graft than in extension; there is no correct position or tension

 Gertel et al. [14] (1993)

Experimental (biomechanical)

10

Graft stress can be avoided with tensioning in extension

 Brady et al. [15] (2006)

Experimental (biomechanical)

12

Stresses (15 N) applied at 20° of flexion or extension minimized rotational and axial forces on the knee; tension (90 N) in extension led to greater compressive forces

 Austin et al. [16] (2007)

Experimental (biomechanical)

10

Knee flexion at 30° is associated with loss of extension

 Mae et al. [19] (2008)

Experimental (biomechanical)

6

Knee flexion at 20° is closely associated to a normal knee

 Kim et al. [17] (2018)

Clinical trial

60

Graft length shown to be longer with knee extended and loose in flexion

 Miura et al. [20] (2006)

Experimental (biomechanical)

10

Dual band fixation (anteromedial/posterolateral bundles): PM bundle overloaded when fixed at 30°/30° and AM bundle overloaded when fixed at 60°/full extension

 Höher et al. [21] (2001)

Experimental (biomechanical)

10

Fixing the graft at 30° of flexion better restored in situ forces and the kinematics of the knee when compared to the extension position

 Asahina et al. [22] (1996)

Clinical trial

44

Superior stability and arthroscopic appearance in the group with the graft fixed at 30 ° of flexion; greater number of extension deficits when compared to fixation in extension

 Speziali et al. [23] (2014)

Systematic review

19

Clinical outcomes were good or excellent in 2/3 of patients regardless of implants

 Steiner et al. [24] (1994)

Experimental (biomechanical)

36

If properly fixed, implants/tendons showed similar strength. Patellar tendon with interference screws showed increased rigidity

 Scheffler et al. [25] (2002)

Experimental (biomechanical)

40

Bonding materials should be avoided. Use of bone block fixation or hybrid fixation may decrease chance of failure

 Brand et al. [26] (2000)

Review article

98

Interference screws in bone-to-bone fixation seems superior; metallic and bioabsorbable screws with similar results

 Eguchi et al. [27] (2014)

Experimental (biomechanical)

4

Fixed-length suspensory devices have a greater mechanical clamping force than those of an adjustable length

 Benedetto et al. [28] (2000)

Clinical trial

113

Bioabsorbable polygluconate screws with similar results when compared to metallic screws

 Drogset et al. [29] (2005)

Clinical trial

41

Metallic screws showed better results than bioabsorbable screws

 Arama et al. [30] (2015)

Clinical trial

40

There are no clinical differences in the use of titanium screws and bioabsorbable screws with hydroxyapatite

 Ma et al. [31]

Clinical trial

30

Fixation with interference screws shows no difference in outcomes when compared to suspensory fixation

 Carulli et al. [32]

Clinical trial

90

Good and similar results when comparing combined fixation with interference screws/sheath versus interference screw/staple

 Weiss et al. [33]

Experimental (biomechanical)

54

Hybrid fixation has biomechanical advantages over simple fixation

 Teo et al. [34]

Clinical trial

64

Supplementary tibial-graft fixation did not benefit ACL reconstruction