Ultrasound Neuromodulation (Low‐Intensity Focused Ultrasound) to Treat Knee Osteoarthritis Pain
Brian M. Ilfeld, Khoa N. Cao, Ruben Branson, Philip Bloom
Journal of Ultrasound in Medicine 2025 · 10.1002/jum.16706
Abstract
Low-intensity focused ultrasound is a non-invasive neuromodulation technique that delivers mechanical forces to a deep location within the body through acoustic pressure waves without affecting tissue between the transducer and focal target. Preliminary studies involving healthy volunteers suggest focused ultrasound reversibly prevents action potential formation similar to a local anesthetic nerve block, but the modality has not been used in patients with existing pain. The current randomized pilot study was undertaken to 1) determine the feasibility and optimize the protocol for a subsequent definitive clinical trial; and 2) monitor for related complications of focused ultrasound when treating knee osteoarthritis pain.
Abstract via europepmc.
Exposures
Exposure 1: Single 15 s sonication of the infrapatellar branch of the saphenous nerve at 150 or 225 W/cm2
Target: saphenous nerve — “infrapatellar branch of the saphenous nerve”
Device: other named manufacturer · Pegasus Neurotechnology, Melbourne, Victoria, Australia · Resonance (driven by a signal generator and power amplifier, Model H-107, Sonic Concepts)
| Waveform | not reported | |
|---|---|---|
| Fundamental frequency (kHz) | not reported | ⚑ |
| Pulse duration (ms) | not reported | |
| Pulse repetition frequency (Hz) | not reported | |
| Duty cycle (%) | not reported | |
| Sonication duration (s) | 15 | ✓✓✓⚑ |
| Free-field pressure (kPa) | not reported | |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | not reported | |
| In-situ pressure (kPa) | not reported | |
| In-situ Isppa (W/cm²) | not reported | |
| In-situ Ispta (W/cm²) | 150, 225swept | ✓✓✓ |
| Pressure, domain unspecified (kPa) | 2,200 | ✓✓✓ |
Participants received one 15 s focused ultrasound (or sham) treatment after which the transducer was removed; intensity was scaled for overlying fat and muscle attenuation. Cohorts were 0 (sham), 150 or 225 W/cm2 spatial-peak temporal-average, randomised 1:2:2.
Flags from extraction
exposures[0].timing.sonication_duration_s— The paper calls the 15 s a 'pulse duration'; recorded as sonication duration, pulse duration left not_reported.exposures[0].unspecified_domain.ispta_w_cm2— Spatial-peak temporal-average intensity given as 150 and 225 W/cm2 (18 W, 27 W); the text says it was scaled for attenuation but does not say whether it applies in water or at the nerve.exposures[0].device.family— The device is Pegasus Resonance; the Sonic Concepts H-107 is named in the sentence as the driver but the transducer maker is not stated explicitly.exposures[0].fundamental_frequency_khz— No frequency is stated in the text.sham_type— Sham is 0 W/cm2 treatment; how it was produced is not described.exposures[0].target.label— Peripheral nerve target, not brain.