From Ionic Agitation to Precision Neuroablation: A Bioengineering Perspective on the Mechanisms, Modalities, and Clinical Applications of Radiofrequency Technology in Pain Management

Radiofrequency ablation (RFA) is a foundational interventional technology in pain management. Despite the diversity of available systems, conventional thermal, internally cooled, bipolar, and pulsed radiofrequency (PRF) all share one biophysical mechanism: high-frequency alternating current (AC) drives tissue ions to oscillate, generating frictional heat within the tissue surrounding the electrode. This localized heating produces predictable patterns of coagulative necrosis shaped by tissue electrical conductivity, electrode geometry, power delivery, and perfusion-related heat dissipation. Classical and contemporary bioheat models, including the Pennes bioheat equation, describe how these variables determine lesion size and morphology. Advances in device engineering have reshaped lesion characteristics through internally cooled probes, bipolar strip-lesioning systems, and pulsed platforms that modulate neural activity while preserving structural integrity. These innovations broaden therapeutic options by enabling targeting of anatomically variable structures, such as the sacral lateral branches, and intraosseous targets, including the basivertebral nerve (BVN). Emerging technologies—high-voltage PRF, hybrid pulsed–thermal systems, and electroporation-based pulsed-field ablation—reflect a growing emphasis on tissue selectivity, energy efficiency, and safety. This narrative review traces the historical development of radiofrequency neurotomy, examines the biophysical principles governing lesion formation (including the Pennes bioheat equation and the roles of current density, impedance, and perfusion), and details the engineering distinctions among modalities. Clinical applications across spinal, joint, and peripheral nerve targets are presented to illustrate how these physical and engineering differences translate into procedural decision-making, and emerging modalities such as high-intensity focused ultrasound (HIFU) and pulsed-field ablation are discussed in the context of the biophysical principles they extend or depart from.