Evers, Stefanie

ABSTRACTIntroduction: The aim of this study was to assess alterations in median nerve (MN) biomechanics within the carpal tunnel resulting from ultrasound‐guided hydrodissection in a cadaveric model. Methods: Twelve fresh frozen human cadaver hands were used. MN gliding resistance was measured at baseline and posthydrodissection, by pulling the nerve proximally and then returning it to the origin. Six specimens were treated with hydrodissection, and 6 were used as controls. Results: In the hydrodissection group there was a significant reduction in mean peak gliding resistance of 92.9 ± 34.8 mN between baseline and immediately posthydrodissection (21.4% ± 10.5%; P = 0.001). No significant reduction between baseline and the second cycle occurred in the control group: 9.6 ± 29.8 mN (0.4% ± 5.3%; P = 0.467). Discussion: Hydrodissection can decrease the gliding resistance of the MN within the carpal tunnel, at least in wrists unaffected by carpal tunnel syndrome. A clinical trial of hydrodissection seems justified. Muscle Nerve 57: 25–32, 2018

ObjectiveTo compare the effectiveness of ultrasound‐guided injections to blind injections in the treatment of carpal tunnel syndrome (CTS) in a large community‐based cohort.MethodsThis study evaluated residents of Olmsted County, Minnesota, treated with a corticosteroid injection for CTS between 2001 and 2010. The proportion of patients receiving retreatment and the duration of retreatment‐free survival between blind and ultrasound‐guided injections were compared. Propensity score matching was used to control for confounding by indication.ResultsIn the matched data set consisting of 234 (of 600) hands treated with a blind injection and 87 (of 89) ultrasound‐guided injection cases, ultrasound guidance was associated with a reduced hazard of retreatment (hazard ratio 0.59 [95% confidence interval (95% CI) 0.37–0.93]). In addition, ultrasound guidance was associated with 55% reduced odds of retreatment within 1 year compared to blind injections (adjusted odds ratio 0.45 [95% CI 0.24–0.83]).ConclusionThis study indicates that ultrasound‐guided injections are more effective in comparison to blind injections in the treatment of CTS.