Table 4 Univariable Cox regression with four different follow-up times for players with ACLR (n = 112)

Second ACL injury, n (%)

17 (15)

28 (25)

35 (31)

43 (38)

1. Time between injury and ACLR, months

0.916

0.785

1.069

0.893

0.785

1.014

0.903

0.809

1.008

0.898

0.812

0.992

Cut-off < 7.1 months (n = 85)

2.875

1.131

7.307

2. Level of play after primary ACLR, n (%)

 Elite (2 top divisions)

1.432

0.239

8.570

1.190

0.320

4.434

1.662

0.487

5.679

 Third–sixth division

1.762

0.415

7.473

0.999

0.349

2.863

1.176

0.415

3.331

Lowest division or youth play, reference^a

3. IKDC (0–100)

1.031

0.980

1.084

1.008

0.974

1.043

1.004

0.974

1.035

1.002

0.976

1.030

4. ACL-RSI (0–10)

1.154

0.878

1.516

1.002

0.818

1.228

1.001

0.834

1.201

1.017

0.862

1.199

5. ACL-QoL (0–10)

1.252

0.845

1.855

1.051

0.794

1.392

1.031

0.802

1.324

1.009

0.805

1.264

6. SMPS—personal standards (1–5)

0.908

0.558

1.478

1.270

0.854

1.888

1.176

0.830

1.666

1.211

0.882

1.661

7. SSP—somatic anxiety (0–100)

1.027

0.973

1.085

1.017

0.974

1.061

1.014

0.977

1.054

1.023

0.989

1.058

8. SSP—psychic anxiety (0–100)

1.013

0.966

1.061

1.013

0.977

1.051

1.015

0.983

1.049

1.018

0.989

1.049

9. SSP—stress susceptibility (0–100)

1.031

0.987

1.078

1.023

0.988

1.059

1.016

0.984

1.048

1.024

0.996

1.053

10. SSP—impulsiveness (0–100)

0.975

0.924

1.029

0.993

0.954

1.033

1.007

0.973

1.043

1.005

0.974

1.036

11. SSP—adventure seeking (0–100)

0.959

0.902

1.020

0.979

0.935

1.026

0.993

0.954

1.034

0.982

0.947

1.019

12. Ankle dorsiflexion, side difference, degrees

1.107

0.869

1.410

1.137

0.945

1.367

0.989

0.840

1.163

0.988

0.908

1.074

13. Knee extension ACLR leg, degrees^b

0.945

0.868

1.028

0.946

0.887

1.010

0.935

0.882

0.991

0.936

0.889

0.987

 Cut-off > −4 degrees (n = 39)^b

1.969

1.015

3.823

1.756

0.959

3.216

14. LSI—single hop for distance, %

1.024

0.968

1.084

1.014

0.969

1.062

1.011

0.970

1.053

1.008

0.971

1.046

15. LSI—side hop, %

1.014

0.989

1.039

1.014

0.995

1.034

1.008

0.991

1.025

1.013

0.997

1.028

16. 5-jump test, cm

1.002

0.997

1.007

1.003

0.999

1.007

1.003

1.000

1.006

1.003

1.000

1.006

17. Tuck jumps total points (0–10)

0.899

0.695

1.164

0.887

0.725

1.084

0.890

0.744

1.065

0.904

0.769

1.062

18. Knee collapse ACLR leg in DVJ, cm

0.986

0.854

1.139

1.036

0.924

1.161

1.078

0.971

1.196

1.045

0.952

1.147

19. Knee collapse non-ACLR leg in DVJ, cm

1.076

0.928

1.248

1.082

0.965

1.213

1.084

0.979

1.201

1.073

0.979

1.176