All ACL reconstruction patients attend the hospital for routine pre-operative assessment-whether involved in the study or not. At this appointment-usually 2-4 weeks before their operation- trial participants will complete the questionnaires related to the study: the Knee Osteo-arthritis Outcome Score (KOOS), the International Knee Documentation Committee (IKDC) subjective knee questionnaire, the Lysholm Knee Questionnaire and the Tegner activity score.