Ultrasound-guided Pericapsular Nerve Group Ethanol Neurolysis for the Management of Metastatic Hip Pain in Advanced Cancer: A Case Series

Abstract

Abstract Hip pain from bone metastases is often severe, refractory, and difficult to control with systemic analgesics due to its complex innervation. The pericapsular nerve group (PENG) block is an interfascial technique targeting articular branches of the femoral, obturator, and accessory obturator nerves, which supply the anterior hip capsule. This technique provides effective analgesia while preserving motor function. Ethanol neurolysis via the PENG approach has been used perioperatively for hip fracture pain. In this case series, we evaluated the efficacy and safety of PENG ethanol neurolysis for metastatic hip pain in patients with advanced cancer. Five patients with confirmed lytic hip metastases and predominantly anterior hip capsular pain were enrolled. All patients fulfilled predefined inclusion criteria, including refractory pain despite optimized systemic analgesia and a positive diagnostic PENG block. The procedure resulted in significant and sustained pain relief, reduced opioid requirements, and improved functional mobility in activities of daily living, with no major adverse events. Functional outcomes were assessed using the Karnofsky Performance Scale. An institutional ethics committee waiver was obtained for this retrospective case series.