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Table 1 Summary of findings table of direct outcomes

From: Transtibial versus independent femoral tunnel drilling techniques for anterior cruciate ligament reconstruction: evaluation of femoral aperture positioning

Outcome

Illustrative comparative risks

No of participants (studies)

Assumed risk

Corresponding risk (95% CI)

On same knee

Distance of aperture to FP

   

On photographed arthroscopic image

On digitized 3d model of specimen

On CT

6.2 mm

5.9 mm

NE

3.4 mm closer (3.6 mm closer:3.2 mm closer)

3.6 mm closer (8.3 mm closer:1.1 mm further)

NEb

20 (1 study)

48 (2 studiesa)

59 (2 studies)

Distance of aperture to FP in PA axis

   

On specimen

On digitized 3d model

1.9 mm anterior

3.7 mm anterior

1.9 mm more posterior

3.3 mm more posterior (6.2 mm more posterior:0.3 mm more posterior)

10 (1 study)

48 (2 studies)

Distance of aperture to FP in PD axis

   

On specimen

On digitized 3d model

3.3 mm proximal

2.9 mm proximal

3.3 mm more distal

2.9 mm more distal (6.1 mm more distal:0.3 mm more proximal)

10 (1 study)

48 (2 studies)

Aperture spatial position in FP

   

On specimen

On CT

100% in highest third

Variable, 50% in lower deep quadrant

30% in highest, 50% in middle, and 20% in lower third

Consistent, 70% in lower deep quadrant

20 (1 study)

20 (1 study)

On contralateral knee on MRI

Greatest distance of aperture to FP

4 mm

1.3 mm closer (6 mm closer:3.4 mm further)

87 (3 studies)

Distance of aperture to FP in PA axis

3.7 mm anterior

3.5 mm more posterior (8.2 mm more posterior:1.2 mm more anterior)

46 (2 studies)

Distance of aperture to FP in DP axis

0.4 mm proximal

1.6 mm more distal (6 mm more distal:2.9 mm more proximal)

46 (2 studies)

Difference in AP position% between aperture and FP

9% anterior

2% more posterior (5% more anterior: 9% more posterior)

20 (1 study)

Difference in DP position% between aperture and FP

9% proximal

10% more distal (18.9% more distal:1.1% more distal)

20 (1 study)

  1. FP, footprint; NE, not estimable
  2. aA third study (72 participant) [57] investigating a substantial modification of TT technique (hybrid TT subgroup) whose result could not be pooled, showed 10 mm assumed risk (of conventional TT subgroup) and corresponding risk of 7.9 mm closer (10.5 mm closer to 5.3 mm closer)
  3. bQualitative synthesis: The results were consistent, both studies [51, 64] found that the TI technique placed aperture closer to the footprint than did the TT technique with mean difference of 2.4 mm and 4 mm