Pulsed radiofrequency targeting the axillary and suprascapular nerves under ultrasound guidance may alleviate chronic shoulder pain effectively, according to a study published in Pain Medicine.
Shoulder pain is a common complaint, leading to frequent referrals for pain management. Pulsed radiofrequency on the axillary and suprascapular nerves has been suggested as a therapeutic strategy for the management of shoulder pain, with ultrasound guidance facilitating selective targeting and more accurate needle placement, while minimizing physician and patient exposure to radiation.
The axillary nerve innervates the anterior and inferior parts of the glenohumeral joint — the posterior and superior parts being covered by the suprascapular nerve — as well as the skin. Thus, targeting both nerves with radiofrequency allows coverage of the entire joint capsule.
In this study, patients were in the lateral decubitus position, with the affected shoulder facing upward. The needle was inserted under ultrasound guidance along the ultrasound beam’s longitudinal axis. Electrical stimulation was then used to confirm proper needle placement. First, motor stimulation of each nerve was conducted at 2 Hz, with resultant palpable contractions or fasciculations of the innervated musculature. Next, sensory stimulation was performed on each nerve at 50 Hz to 100 Hz, to determine paresthesia coverage in the relevant nerve distribution. After paresthesia coverage confirmation, pulsed radiofrequency (1 6-minute cycle) was conducted at each nerve (45 V, 42ᵒC).
This approach was found to be effective, but the physicians warned of 2 potential pitfalls to be considered when undertaking this method: the possibility of pneumothorax during suprascapular targeting and the risk for arterial injection because of the proximity of vessels when inserting needles.
“By adapting an approach developed in acute pain management, we can safely deliver pulsed radiofrequency to the suprascapular and axillary nerves for the treatment of shoulder pain,” noted the authors, adding, “This could be the next step in the quest for a more comprehensive treatment of painful shoulder syndrome.”
Esparza-Miñana JM, Mazzinari G. Adaptation of an ultrasound-guided technique for pulsed radiofrequency on axillary and suprascapular nerves in the treatment of shoulder pain [published online January 25, 2019]. Pain Med. doi:10.1093/pm/pny311