Preselection of MRI slices compared with independently selected MRI slices did not significantly improve the interrater reliability of the tibial tubercle-trochlear groove distance measurement in patients with patellar instability, according to the results of this study.

"The key findings of this study are that inter-rater reliability of [tibial tubercle-trochlear groove] TT-TG distance measurement on MRI is generally good and not highly dependent on the specific MRI slices selected for the measurements,” Robert Magnussen, MD, told Healio Orthopedics. “In contrast, inter-rater reliability of trochlear morphology measures on axial MRI slices (specifically trochlear depth and sulcus angle) is only fair. Interrater reliability of sulcus angle measurements can be improved pre-selecting slices for measurements. The high dependence of sulcus angle and trochlear depth on slice selection suggest that trochlear morphology cannot be completely and accurately described by measurements made on a single axial MRI slice."