An MRI-Based Method for the Morphologic Assessment of the Anterior Tibial Tuberosity.

Background

A prominent anterior tibial tuberosity (or tibial tubercle) can be seen in ongoing Osgood-Schlatter disease (OSD) in teenagers or as a sequela of OSD in adults. Current radiological methods do not provide a true anatomical assessment of the tibial tuberosity; therefore, we proposed and developed a Magnetic Resonance Imaging (MRI)-based method for measuring the anterior tibial tuberosity index, aiming to deal with the current lack of effective techniques for accurately assessing these particular morphologic features.

Methods

A retrospective study included 47 knees with tibial tuberosity measurements on both true sagittal MPR images of 3D proton density (PD)-weighted MRI sequences and lateral knee radiographs. The same landmarks were followed and the anterior tibial tuberosity index (ATTI) was measured.

Results

The comparison of the results obtained by the two methods demonstrates that our method is reliable and reproducible with substantial inter- and intra-observer agreement. The intraclass correlation coefficient was 0.9250 (95% CI: 0.8654 to 0.9582), indicating excellent reliability between the two methods. A strong positive correlation was also identified, with a correlation coefficient of r = 0.8746 (95% CI: 0.7845 to 0.9286, p < 0.0001) between the two methods. No significant deviation from linearity was observed by analyzing the linear model validity using the cusum test (p = 0.62).

Conclusions

Based on these results, we encourage the use of 3D PD-weighted MRI sequences for the measurement of the anterior tibial tuberosity on MRI in order to avoid unnecessary exposure to ionizing radiation and potentially obtain a more accurate measurement. Future larger studies should also explore the benefit of utilizing 3D sequences over 2D lateral projections to minimize measuring bias.