CT and MRI Measurements of Tibial Tubercle–Trochlear Groove Distances Are Not Equivalent in Patients With Patellar Instability

Abstract

The TT-TG distance can be measured with excellent interrater reliability on both MRI and CT; however, the values derived from these 2 tests may not be interchangeable. This observation should be taken into consideration when MRI is used for surgical planning because MRI may underestimate the TT-TG distance when compared with CT.