Abstract
Purpose
To evaluate the relationship between TT-TG distance and lower-limb anatomical parameters in recurrent patellar dislocation.Methods
Weight-bearing long-leg radiographs and knee CT scans of 99 patients with recurrent patellar dislocation were reviewed. Trochlear dysplasia was classified according to the Dejour version 2 classification. Tibial tubercle-trochlear groove (TT-TG) distance was measured together with coronal alignment (mFTA and related angles) and rotational alignment (tibiofemoral rotation and tibial torsion). Patients were stratified by TT-TG distance and mFTA-based alignment. Pearson correlations examined associations among anatomical parameters. In the TT-TG ≥ 20 mm group, multivariable regression explored factors potentially associated with TT-TG distance.Results
Most patients had trochlear dysplasia, and a high proportion were classified as Dejour type C or D (71/99, 71.7%). Overall, TT-TG distance was significantly positively correlated with TFR (r = 0.504, P Conclusion
In patients with recurrent patellar dislocation, TT-TG distance was positively associated with tibiofemoral rotation but not with coronal lower-limb alignment. This association was more evident in patients with TT-TG < 20 mm and was attenuated in those with TT-TG ≥ 20 mm. These findings suggest that TT-TG distance should be interpreted together with rotational alignment and trochlear morphology when planning individualized treatment.