Clinical value of 3D-FIESTA-C sequence in evaluating the arcuate ligament of the elbow joint: a retrospective study

Cubital tunnel syndrome (CuTS) is a commonly seen form of compressive neuropathy. This study aimed to assess the clinical value of 3D-FIESTA-C for evaluating the arcuate ligament in patients with CuTS. Between October 2018 and May 2019, 22 inpatients diagnosed with CuTS were enrolled (15 males, 7 females; mean age 60.91 ± 7.38 years). All patients underwent preoperative 3D-FIESTA-C scanning of the elbow joint and subsequently received cubital tunnel release. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and kappa value of the 3D-FIESTA-C sequence in displaying the arcuate ligament in its entirety and ulnar nerve were calculated using the intraoperative results as the gold standard, and the consistency test between this sequence and intraoperative arcuate ligament was compared. Paired t-test was used to compare the differences of arcuate ligament thickness measured by the 3D-FIESTA-C sequence and intraoperative exploration. P < 0.05 was considered statistically significant. The 3D-FIESTA-C revealed a comparatively low display rate on the site of olecranon and olecranon attachment when evaluating arcuate ligament (81.8% and 68.2%, respectively). Intraoperative exploration showed the absence of arcuate ligament and ulnar nerve dislocation in 3 patients, while the 3D-FIESTA-C revealed the absence of the arcuate ligament in 2 patients. Using ulnar neurolysis of the cubital tunnel as the gold standard, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and Kappa of the 3D-FIESTA-C for displaying the arcuate ligament in its entirety were 81.8%, 79.0%, 100%, 100%, 42.9%, and 0.51, respectively. When using the 3D-FIESTA-C to display the arcuate ligament on the site of the ulnar nerve, the above values were 95.5%, 100%, 66.7%, 95.0%, 100%, and 0.78, respectively. There was no significant difference in arcuate ligament thickness measured by the 3D-FIESTA-C and intraoperative exploration (0.58 ± 0.15 mm Vs. 0.68 ± 0.34 mm, P = 0.37). The 3D-FIESTA-C can accurately display the morphological features and positions of the arcuate ligament of the elbow joint and its relationship with the ulnar nerve. And it can also be used to conduct quantitative measurement of the thickness of the arcuate ligament. Not applicable.