Tibiofemoral rotation in patellofemoral pathology: a systematic review of imaging modalities, measurement techniques and clinical relevance.
BACKGROUND Patellofemoral pathology is multifactorial with increasing evidence suggesting that tibiofemoral rotation (TFR) contributes to pain, maltracking and recurrent instability. Reported TFR values vary considerably because of differences in imaging modality, acquisition protocol, axial slice selection and reference axes. The aim of this review is to analyse the literature available on tibiofemoral rotation in patellofemoral pathology. METHODS A PRISMA-compliant systematic review of PubMed/MEDLINE, Embase and Scopus was performed up to May 2026. Studies assessing TFR in patellofemoral instability or resultant anterior knee pain were included. Data regarding imaging modality, measurement technique, reference axes, normative and pathological values, interaction with tibial tubercle indices, and clinical relevance were extracted and synthesised qualitatively. RESULTS Twenty-five studies were included, predominantly retrospective observational Level III studies. MRI was used in nine studies, CT alone in eight, and both modalities in four. Reference-group mean TFR values ranged from 3.8° internal to 5.7° external rotation, whereas pathological cohort means ranged from 1.6° to 12° external rotation. Where full participant ranges were reported, values overlapped substantially between healthy participants (-8.7° to 11.7°) and patellofemoral-instability cohorts (-6.5° to 21.6°). Increased external TFR was associated with patellar maltracking, recurrent instability and rotational effects on TT-TG interpretation; however, reported values were dependent on imaging modality, reference-axis definition and knee position. CONCLUSION Current evidence supports an association between increased external tibiofemoral rotation and patellofemoral pathology, although methodological standardisation remains necessary before TFR can be reliably incorporated into routine clinical decision-making.