Summary
This research investigates the correlation between Ultrasonographic Patellar Tendon-Trochlear Groove distance, a new ultrasound-based knee lateralization assessment, and established CT-based measures.
Abstract
Introduction
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). Conventional techniques, while reliable, necessitate patient selection due to the associated radiation exposure, hence limiting their application. Thus, USPT-TG, a non-invasive and convenient measure, might strongly correlate with traditional indices, offering a potentially valuable addition to clinical practice.
Methods
This cross-sectional study was meticulously conducted from February through May 2023. Our patient cohort comprised 75 individuals (47 females, 28 males) taken for our hospital's joint replacement, osteotomy or ACL reconstruction procedures. These patients underwent routine preoperative CT imaging. The demographic parameters exhibited considerable variation, with an age range of 12-95 years (average 51.0±23.5 years) and a BMI range of 16.8-40.8 (average 25.5±4.8).
The ultrasound machine used was the SONIMAGE HS2 (KONICA MINOLTA, Japan), and the transducer model used was the L11-3. The measurement method was confirmed by checking whether the preoperative CT scan was taken in an extended or slightly flexed position. According to that angle, the transducer was positioned 1cm distal from the inferior edge of the patella in the short-axis orientation. We captured images of the patellar tendon and the trochlear groove of the femur. The Patellar-Tendon-Trochlear Groove distance (hereafter referred to as 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 primary 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: 8.3±2.8mm, TT-TG: 12.5±3.5mm, PT-TG: 9.0±2.9mm, and TT-PCL: 17.4±4.4mm. Correlation analysis revealed the following results: USPT-TG vs. TT-TG: r=0.42 (p<0.0001), USPT-TG vs. PT-TG: r=0.71 (p<0.0001), and USPT-TG vs. TT-PCL: r=0.31 (p<0.01). USPT-TG demonstrated a moderate to strong positive correlation with TT-TG, PT-TG and TT-PCL.
Discussion And Conclusion
Our investigation revealed that the novel ultrasonographic measure, USPT-TG, positively correlates with well-established CT-based indices, TT-TG, PT-TG and TT-PCL. These relationships 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 could revolutionize knee joint lateralization assessment, an area of orthopedics traditionally dominated by CT. This novel method may advance research and clinical practice in this critical domain, eventually improving surgical outcomes and patient quality of life.