Increased tibial tubercle torsion is associated with advanced lateral patellofemoral osteoarthritis

To investigate whether the emerging anatomical parameters of the patellofemoral (PF) joint, including tibial tubercle torsion (TT torsion), the sagittal tibial tuberosity-trochlear groove (sTT-TG) distance, the tibial tuberosity rotational angle (TT-RA), the tibiofemoral rotation and tibial tuberosity lateralisation (TT lateralisation), are associated with advanced lateral patellofemoral osteoarthritis (PFOA).

This retrospective study analysed patients from a preoperative total knee arthroplasty workup database. PF cartilage lesions of International Cartilage Repair Society Grade 3 or higher were defined as advanced. TT torsion, sTT-TG, TT-RA and TT lateralisation were assessed based on computed tomography imaging. Additionally, tibiofemoral rotation, tibial tuberosity-trochlear groove distance, Caton-Deschamps index, femoral antetorsion, tibial torsion and the hip-knee-ankle (HKA) angle were also included in the analysis. Binary logistic regression analysis and Mann-Whitney U test were used to examine associations between the advanced PFOA and the measured anatomical parameters.

Fifty-two knees/patients (35 females and 17 males) could be included: 20 with advanced lateral PFOA, 13 with advanced medial PFOA and 19 without advanced PFOA. Femoral antetorsion (odds ratio [OR] = 1.094, 95% confidence interval [CI] = 1.029-1.164; p = 0.004) and valgus HKA angle (OR = 1.152, 95% CI = 1.066-1.247; p < 0.001) met the Bonferroni-adjusted threshold (p < 0.005) for association with lateral PFOA. TT torsion was significant at the 0.05 level but not after the Bonferroni adjustment (OR = 1.138, 95% CI = 1.027-1.260; p = 0.013). Analysing isolated lateral vs. medial PFOA, higher TT torsion and femoral torsion, as well as valgus HKA angle, exhibited a Bonferroni-adjusted statistically significant correlation with advanced lateral PFOA (p = 0.003, p < 0.001 and p < 0.002, respectively).

TT torsion is associated with advanced lateral PFOA and may represent an additional risk factor. This finding underscores the substantial role of rotational malalignment in the pathogenesis of lateral PFOA. Recognising the role of TT torsion and its intercorrelation with the HKA angle and femoral antetorsion may refine clinical assessment of PF conditions and inform surgical strategies.

Level III.