Comment on "Radiological risk factors in different patterns of patellar instability".

I read with great interest the recently published article by Chouhan et al. examining radiological risk factors across different patterns of patellar instability. The authors investigated trochlear dysplasia, tibial tubercle-trochlear groove (TT-TG) distance, and patellar height across single-episode, recurrent, and habitual patellar dislocation phenotypes. While this phenotype-based imaging approach addresses a clinically relevant question, several methodological and conceptual considerations may limit the robustness and clinical translatability of the reported between-group differences. The analysis was performed at the knee level despite inclusion of bilateral cases, without accounting for within-patient clustering, potentially inflating statistical significance. In addition, exclusion of patients who underwent stabilization procedures, particularly among single-episode dislocators, may introduce spectrum and selection bias, exaggerating apparent phenotype contrasts. The absence of formal inter- and intraobserver reliability assessment further constrains interpretation, especially given the known measurement variability of TT-TG distance, patellar height indices, and dysplasia grading. Reported TT-TG differences between single-episode and recurrent instability were small, with substantial overlap and without confidence intervals, reliability metrics, or threshold-based analyses, limiting clinical actionability within contemporary multifactorial decision frameworks. Inclusion of habitual patellar dislocation, often a developmental condition with distinct and entrenched structural abnormalities, within the same comparative construct as episodic instability raises concerns regarding construct validity and extrapolation of management implications. In conclusion, this work tackles an important clinical topic, and its conclusions could be further consolidated by incorporating cluster-aware analyses, clearly documenting exclusion patterns and reporting measurement reproducibility and TT-TG analyses aligned with clinically actionable thresholds within a multifactorial anatomical framework.