Pericapsular Nerve Group Phenol Neurolysis for Refractory Metastatic Hip Pain: A Case Series

Cancer-related hip pain due to tumor infiltration is challenging, especially in patients with limited life expectancy. While ultrasound-guided pericapsular nerve group (PENG) phenol neurolysis has been reported in isolated cases, systematic evidence on effectiveness and safety remains limited.

We conducted a prospective case series of three patients with refractory metastatic hip pain who underwent ultrasound-guided PENG phenol neurolysis using 10 mL of 10% nonglycerinated phenol, with six-week follow-up. Assessments were performed at baseline, 10 minutes, 24 hours, and Weeks 1, 2, 4, and 6 using validated measures: pain intensity (Visual Analog Scale [VAS]), neuropathic pain (Douleur Neuropathique 4 [DN4]), opioid consumption (oral morphine milligram equivalents [MME]), and function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]). Adverse events were predefined as new motor deficit, persistent sensory loss, infection, bleeding, or vasovagal reaction, and were monitored with serial neurochecks for 4 hours postprocedure and at each follow-up through Week 6.

All patients-bedbound at baseline with VAS 10/10-experienced rapid and marked analgesia, with VAS scores of 1-2 within 10 minutes and sustained relief through six weeks. DN4 scores fell below the diagnostic threshold (≤3) in all cases. Daily opioid consumption decreased by 47%-77%, and all patients achieved assisted ambulation within 24 hours. No motor weakness occurred; the only adverse event was mild, transient anterior-hip hypoesthesia.

Ultrasound-guided PENG phenol neurolysis (10% phenol) may be a valuable motor-sparing option for refractory cancer-related hip pain in selected palliative care patients. These preliminary findings warrant evaluation in larger, controlled studies.