Evaluating the efficacy of obturator cryoneurolysis for hip adductor spasticity: An observational, prospective study

Abstract Background Hip adductor spasticity is a common affliction among patients with disorders of the central nervous system. Cryoneurolysis is a novel intervention for spasticity involving the application of extreme cold to a nerve. This induces axonal breakdown, relieving spasticity. Objective To evaluate the effect of cryoneurolysis on hip spasticity in adults. Design This study was an observational, single‐center, prospective cohort study. Participants Twenty adult patients who had been scheduled to receive cryoneurolysis for hip adductor spasticity as part of their standard treatment were included. Patients with a history of previous nerve procedures, cryoneurolysis, or surgery of obturator nerves were excluded. Interventions Cryoneurolysis of anterior and posterior branches of the obturator nerve was performed. Main Outcome Measures The primary outcome was spasticity severity on the Modified Ashworth Scale. Additional outcomes included passive and active ranges of motion and the goal attainment scale. Results There was a large reduction in Modified Ashworth Scale scores at 3 months on the right side (Wilcoxon W [ W ] = 6.0, p < .01; rank‐biserial correlation [rrb] = −0.89, 95% confidence interval [CI] = −1.00, −0.63) and the left ( W = 0.0, p < .001; rrb = −1.00, 95% CI = −1.00, −1.00). The decreases persisted at 1 year on the right ( W = 0.00, p < .001; rrb = −1.00, 95% CI = −1.00, −1.00) and the left ( W = 12.0, p < .05; rrb = −0.69, 95% CI = −1.00, −0.10). Maximum passive range of motion increased on the right side 1 year after treatment (repeated measures analysis of variance p < .05, ηp 2 = 0.14, 95% CI = 0.07–0.26]) but not on the left side ( p = .24, ηp 2 = 0.07, 95% CI = 0.04–0.21). Conclusions Cryoneurolysis resulted in decreased spasticity severity lasting for 1 year. Cryoneurolysis merits further investigation as a potential long‐lasting, minimally invasive, drug‐free intervention for hip adductor spasticity.