Table 2 Predictive factors investigated across the eight studies

Physical activity rating scale (Tegner,^{32,34,35,37,39}, Noyes³² and Marx³⁴)

Psychovitality questionnaire³²

(score ≥ 15)

Body Mass Index (BMI)^33,35

Knee specific patient reported outcome measure (Lysholm,³² International Knee Documentation Committee [IKDC]³² and ‘knee function’³³ (defined as 2 questions from IKDC)

Knee-Self Efficacy Scale (K-SES) Present³⁹

Weight^33,36

Passive knee range of motion³³

K-SES Future³⁹

Time to surgery^33,34

Concentric quadriceps torque³³

Estimation of ability to return to preinjury level³⁸

Graft type (bone-patella tendon-bone)³³

Eccentric quadriceps torque³³

Estimation of time (number of months) to achieve postoperative markers³⁸

Smoking status³⁴

Concentric and eccentric hamstring torque³³

Goal to return to preinjury level³⁸

Anterior knee pain³³