Editorial Commentary: Magnetic Resonance Imaging Is Helpful in Predicting High-Grade Knee Rotatory Instability: But When in Doubt, Always Examine the Patient.

Abstract

Unrecognized rotatory instability as evidenced by a high-grade pivot shift is well known to compromise anterior cruciate ligament (ACL) reconstruction results. By measuring which patients have anterior tibial subluxation of the lateral compartment ≥ 6 mm on a preoperative MRI, surgeons may be better able to counsel patients on postoperative expectations, as well as prepare for additional procedures to treat high-grade rotatory instability. Additionally, as there is an increased incidence of lateral meniscus tears in high-grade rotatory ACL lesions, surgeons should be vigilant and prepared to repair lateral meniscus root and ramp lesions. Furthermore, early identification of those patients with anterior tibial subluxation of the lateral compartment ≥6 mm will provide the opportunity for early surgery, as it is known that patients with high-grade rotatory instability are likely to sustain further intra-articular damage and have poorer outcomes if surgery is delayed. However, when there is doubt of high-grade rotatory instability after an ACL injury, examining the patient with a pivot shift maneuver should still be the "gold standard".