Description
Topic: Knee - Patellofemoral
Objectives: This comprehensive investigation seeks to elucidate the correlation between an innovative, ultrasonographic lateralization assessment, namely, the Ultrasonographic Patellar Tendon-Trochlear Groove distance (USPT-TG), and well-established CT-based measures, such as the Tibial Tubercle- Trochlear Groove distance (TT-TG).
Methods: This cross-sectional study was meticulously conducted from February through May 2023. Our patient cohort comprised 28 individuals (21 females, 7 males) taken for our hospital's joint replacement or ACL reconstruction procedures. These patients underwent routine preoperative CT imaging. The demographic parameters exhibited considerable variation, with an age range of 12-87 years (average 57.0 years) and a BMI range of 16.8-40.8 (average 26.9). The transducer was positioned 1cm distal from the inferior edge of the patella in the short-axis orientation. USPT-TG was measured as the vertical distance between the patellar tendon's center and the trochlear groove's lowest point, where tangents were drawn. The objective was to examine the correlation of USPT-TG with preoperatively measured CT-based indices, namely TT-TG, PT-TG, and Tubercle-Trochlear PCL (TT-PCL). We relied on Pearson's correlation coefficient for this analysis, with the significance level conservatively set at p=0.05.
Results: The average measurements across our patient sample were as follows: USPT-TG: 8.2mm (range 4.1-15.4), TT-TG: 12.3mm (range 5-19), PT-TG: 9.5mm (range 4-16), and TT-PCL: 16.9mm (range 10-26). Correlation analysis revealed the following results: USPT-TG vs. TT-TG: r=0.56 (p<0.01), USPT-TG vs. PT-TG: r=0.69 (p<0.01), and USPT-TG vs. TT-PCL: r=0.35 (p>0.05). USPT-TG demonstrated a moderate to strong positive correlation with both TT-TG and PT-TG.
Conclusions: Our investigation revealed that the USPT-TG, positively correlates with CT-based indices, TT-TG, and PT-TG. This relationship might be attributable to the anatomical configuration of the knee, where the patellar tendon extends from the patella to the tibial tubercle. Thus, if the trochlear groove could be reliably identified via ultrasound, USPT-TG could be an effective surrogate for the traditional TT-TG measure in assessing knee joint lateralization. Given its convenience and non-invasive nature, ultrasonography might be useful for knee joint lateralization assessment, an area of orthopedics traditionally dominated by CT and MRI.
