Ultrasound and electrical stimulator-guided obturator nerve block with phenol in the treatment of hip adductor spasticity in long-term care patients: a randomized, triple blind, placebo controlled study.

Objective: To evaluate the effectiveness of ultrasound-guided phenol nerve block in the treatment of severe hip adductor spasticity in long-term care patients.

Methods: Double-blind placebo-controlled trial with a 9-month follow-up period.

Setting: A 250-bed long-term care hospital and the infirmary units of 5 regional hospitals.

Participants: Twenty-six long-term care patients with bilateral severe chronic hip adductor spasticity affecting perineal hygiene and nursing care.

Interventions: Patients were randomized to 2 groups that received ultrasound and electrical stimulator guided obturator nerve block using either 5% phenol in aqueous solution or saline.

Main Outcome Measures: The primary outcome measure was the Modified Ashworth Scale, which reflected the severity of hip adductor spasticity. Secondary outcomes included Goal Attainment Scale (GAS), hygiene score, distances between the knees during fast and slow passive hip abductions; passive range of movement for hip extension and knee extension. Pain was assessed using the Pain Assessment in Advanced Dementia Scale.

Results: Twenty-six patients (7 males; mean age = 77, standard deviation = 14) were recruited. At week 6 post-injection, 12/16 (75%) patients in the treatment group vs 1/10 (10%) patients in the control group had at least 1-point reduction of Modified Ashworth Scale (P = .001) on both hip adductors. There was also significant improvement in the GAS, as well as the hygiene score, resting position, and distances between the knees during fast and slow passive hip abductions in the treatment group, which persisted until week 36. No significant difference in the Pain Assessment in Advanced Dementia Scale was found between the 2 groups. No serious phenol nerve block related adverse effects were reported.

Conclusions: Obturator neurolysis with 5% aqueous phenol as guided by both ultrasound and electrical stimulation can safely and effectively reduce hip adductor spasticity, thus, improving hygiene scores and patient-centered outcomes measured by the GAS in affected long-term care residents.