Measuring direct and indirect tendon parameters to characterize the proximal tendinous complex of the rectus femoris in football and futsal players.

Objective: To present unprecedented radiological parameters that characterize the angle between the direct and indirect tendons of the proximal rectus femoris (RF) and its inclinations and to evaluate the population variability according to demographic variables. Materials and methods: From September 2019 to July 2021, using MRI multiplanar reconstructions of the proximal thigh/hip, two blinded radiologists measured the direct and indirect tendon angle and the inclination of each tendon in different planes. The intra- and inter-observer agreements were assessed with Bland-Altman analysis and intraclass correlation coefficient (ICC). The correlations between radiological parameters and demographic variables were evaluated using linear regression, Student's t-test, and analysis of variance. Results: We performed 112 thigh/hip MRI scans on 91 football players of different age, gender, and disciplines (football and futsal). For observer 1 (the reference), the mean direct and indirect tendon angle was 56.74° ± 9.37, the mean indirect tendon slope was -7.90° ± 7.49, and the mean direct tendon slope was 22.16° ± 5.88. The three measurements showed inter- and intra-observer agreement (mean differences ∼0). No correlation was observed between age and the parameters. Likewise, no statistically significant differences were found for gender, dominant limb, examined limb, and sport. Conclusion: There is an inter- and intra-observer agreement in the measurements of the direct and indirect tendon angle and the inclination of each tendon. There is population variability in the proximal tendinous complex unrelated to demographic factors. These results allow further detection of morphological patterns that represent a risk factor for lesions in the RF in professional football and futsal players and other sports.

Validation of the effectiveness of augmented reality-assisted vascular puncture: An experimental model.

PURPOSE: To demonstrate that the augmented reality-assisted puncture technique improves the efficacy of ultrasound-guided puncture to get central venous access (CVA), allows the image to be obtained without limitations, freeing the hands and keeping the gaze continuously on the working field, which contributes to improving the safety of the procedure. MATERIAL AND METHODS: A gelatin mould with a latex surface and a chicken breast with silicone tubes inside were used to simulate vascular punctures. Images were obtained by an ultrasound scanner and post-processed with a specific software. A hologram was obtained and projected onto the previously delimited surface to be punctured. The variables related to image acquisition, the characteristics of the structure to be cannulated and the percentage of successes in the first attempt were analysed. Six operators were involved, using different ultrasound scanners. Efficiency was examined after the application of technical improvements in the process. RESULTS: Seventy-six punctures were performed, guided by two different ultrasound scanners, divided into two groups: 37 with 33 successes (sigma = 3.52 with a process efficiency of 97.98%) and after technical improvements, 39 with 38 successes (sigma = 4.07 with a process efficiency of 99.4%). There are no significant differences among the operators (X2 p = 0.47) and between the ultrasound scanners (X2 p = 0.56). CONCLUSIONS: The augmented reality ultrasound-assisted CVA technique may be the next step in standardising the process of cannulation of vascular structures. This technique provides greater accuracy, greater comfort by freeing the hands and keeping the gaze on the working field, better ultrasound image quality, and eliminates variability between operators and sonographers.