Letter to the Editor: Decreased Association Between Patellar Axial Malalignment and Patellar Height and Increased Association Between Patellar Axial Malalignment and Tibial Tubercle–Trochlear Groove During Weightbearing

To the Editor,

I read with great interest the article by Chen et al. titled, “Decreased Association Between Patellar Axial Malalignment and Patellar Height and Increased Association Between Patellar Axial Malalignment and Tibial Tubercle–Trochlear Groove During Weightbearing” [1]. I commend the authors for their contribution to understanding the dynamic evaluation of patellofemoral joint stability under functional loading conditions. The authors' findings that weightbearing CT scanning reveals a stronger correlation between patellar axial malalignment and tibial tubercle–trochlear groove (TT-TG) distance highlight the importance of functional imaging in the preoperative assessment of recurrent patellar dislocation. Furthermore, the identification of the bisect offset index as the strongest predictor of recurrent dislocation under weightbearing conditions provides a practical, quantifiable metric to guide clinical decision-making and surgical planning.

With this in mind, I respectfully would like to offer several suggestions for future research. First, incorporating additional factors such as femoral version, rotational profile, and Q-angle would provide a more comprehensive understanding of patellar instability by capturing dynamic soft tissue interactions and axial malalignment under functional conditions, which nonweightbearing evaluations often underestimate. Second, prospective studies assessing postoperative outcomes based on weightbearing imaging–guided surgical planning would validate the clinical utility of the bisect offset index, since weightbearing conditions better reflect actual kinematic states. Finally, multicenter studies involving diverse ethnic populations would ensure broader applicability of these findings, as the current study cohort comprised exclusively Asian patients [1].

In conclusion, this study [1] represents a real advancement in improving our approaches to diagnostic evaluation and surgical management of recurrent patellar dislocation. Weightbearing assessments better reflect the true kinematic position of the patella, similar to how cervical dynamic MRI in various positions (e.g., flexion, extension, and standing) provides a more accurate evaluation of cervical spinal stenosis compared to static standing imaging alone [2]. Weightbearing imaging is poised to become a cornerstone of contemporary patellofemoral assessment, and I look forward to further progress in this field.