Abstract Purpose To evaluate the influence of knee rotation angle (KRA) on tibial tubercle‐trochlear groove (TT‐TG) distance measured by computed tomography (CT) in female anterior knee pain (AKP) patients. To assess how correcting for knee rotation affects TT‐TG values. To correlate rotational corrected TT‐TG with the tibial tubercle‐posterior cruciate ligament (TT‐PCL) distance and tibial tubercle lateralisation (TTL) ratio. Methods A retrospective study was performed on 100 consecutive female AKP patients (183 lower limbs) who underwent torsional CT scans. TT‐TG distance was measured and KRA was determined. Rotational‐corrected TT‐TG (RC TT‐TG) values were calculated by neutralising knee rotation. Moreover, TT‐PCL distance and TTL were measured. Two orthopaedic surgeons independently performed all measurements. Spearman correlation and linear regression analyses were used to evaluate the relationship between KRA and TT‐TG changes. Results The mean native TT‐TG was 17.22 ± 4.20 mm, mean KRA was 8.81 ± 5.08° and mean corrected TT‐TG was 9.34 ± 4.70 mm. The difference between noncorrected and corrected TT‐TG distance showed a very strong positive correlation with KRA ( ρ = 0.934, p < 0.001). Linear regression analysis demonstrated that KRA explained 73.3% of the variability in TT‐TG changes ( R ² = 0.733), with TT‐TG decreasing by approximately 0.84 mm for each degree of knee rotation. TT‐TG distance showed a moderate positive correlation with TT‐PCL ( ρ = 0.515, p < 0.001). In contrast, rotational‐corrected (RC) TT‐TG demonstrated a stronger correlation with TT‐PCL ( ρ = 0.644, p < 0.001). The Spearman correlations show a moderate positive association between the normal TT‐TG and TTL ( ρ = 0.451, p < 0.001), while the RC TT‐TG exhibits a stronger correlation with TTL ( ρ = 0.539, p < 0.001). Conclusion Knee rotation is a significant factor affecting TT‐TG measurement. Measuring TT‐TG after correcting knee rotation to neutral provides a more accurate estimation of this measurement. RC TT‐TG correlates more closely with rotation‐independent tibial‐based measurements. Level of Evidence Level IV.
Sanchis‐Alfonso et al. (Thu,) studied this question.