Clinical SANTI classification of arthrogenic muscle inhibition has an excellent inter-rater and intra-rater reliability in preoperative and post-operative anterior cruciate ligament rupture.

Purpose: Arthrogenic muscle inhibition (AMI) is a reflexive shutdown of the quadriceps muscles following a knee injury or surgery that presents with or without hamstring contracture. This complication can be classified according to the SANTI classification, but the reproducibility of this clinical classification has not yet been demonstrated.

Methods: This single-centre longitudinal observational study included 140 patients who were within 6 weeks of an ACL rupture.