Knee rotation significantly increases measured tibial tubercle-trochlear groove distance in female patients with anterior knee pain: Findings after rotational measurement correction.
retrospective_cohort · Level III
Where this comes from
- Record sourced from PubMed, PMID 41810424.
- Also identified by DOI 10.1002/jeo2.70681 and PMC identifier 12969210.
- Licence recorded as CC BY.
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Abstract
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. 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. 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 (<i>ρ</i> = 0.934, <i>p</i> < 0.001). Linear regression analysis demonstrated that KRA explained 73.3% of the variability in TT-TG changes (<i>R</i>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 (<i>ρ</i> = 0.515, <i>p</i> < 0.001). In contrast, rotational-corrected (RC) TT-TG demonstrated a stronger correlation with TT-PCL (<i>ρ</i> = 0.644, <i>p</i> < 0.001). The Spearman correlations show a moderate positive association between the normal TT-TG and TTL (<i>ρ</i> = 0.451, <i>p</i> < 0.001), while the RC TT-TG exhibits a stronger correlation with TTL (<i>ρ</i> = 0.539, <i>p</i> < 0.001). 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 IV.