Figure legends
Figure 1. Ultrasound-guided injection image (left: short-axis injection; right: long-axis injection). (a) The position of in-plane short-axis injection at proximal inlet of the carpal tunnel. (b) The short-axis view shows that the MN separated from the subsynovial connective tissue (arrowheads) via hydrodissection (HD) (*: Injectate). (c) The short-axis view shows that the MN was separated from the flexor retinaculum (FR) (arrows) via HD (*). (d) The position of the in-plane long-axis injection advancing from the wrist crease to the palm. (e) The long-axis view shows swollen nerve fascicles, FR (arrows), and inflamed tendons in the same plane. (f) The long-axis view shows that the MN separated from the FR (arrows) via HD.
MN: median nerve; FDS: flexor digitorum superficialis; FDP: flexor digitorum profundus.
Figure 2. Study flow diagram.
Figure 3. The mean scores of SSS and FSS in both groups at each follow-up time point (mean ± standard error). The result showed a significant reduction of SSS and FSS at 1 month post-injection between groups (short-axis > long-axis group).
SSS = symptom severity scale; FSS = functional status scale
*p <0.05; Mann-Whitney U test.
Figure 4. Follow-up ultrasonography imaging after injection (left: short-axis group; right: long-axis group). (a) The position of the short-axis scan at the proximal inlet of the carpal tunnel. The injectate (*) can be observed between the median nerve (MN), flexor retinaculum (FR) (arrows), and subsynovial connective tissue (SSCT) (arrowheads) in the short-axis scan (b) and long-axis scan (c). (d) The position of the long-axis scan from the wrist crease to the palm. The injectate (*) can be observed between the MN, FR (arrows), and SSCT (arrowheads) in short-axis scan (e) and long-axis scan (f). Both, the short- and long-axis scans show more injectate (*) between the MN and SSCT in the short-axis group compared to the long-axis group.
MN: median nerve; SSCT: subsynovial connective tissue; FDS: flexor digitorum superficialis.