A Multiplanar Reformatting Technique to Correct for Scanner Misalignment During Computed Tomography Measurement of...

The tibial tuberosity-trochlear groove distance (TT-TG) is a commonly used measurement that impacts clinical decision making for patellofemoral instability. When measured using 2-dimensional axial slices from imaging modalities like computed tomography (CT) scans, it has been shown to be prone to error depending on patient alignment with the scanner's longitudinal axis. In this technique article, we describe a method using multiplanar reformatting on 2-dimensional CT scans to create an altered coordinate system to measure TT-TG measurements more accurately and efficiently. This method can drastically impact the accuracy and reproducibility of TT-TG measurements for misaligned scans and can help ensure that patients are treated appropriately for their individual level of dysplasia.