Refractory Chronic Knee Pain After Total Knee Replacement Successfully Treated With L4 Dorsal Root Ganglion Pulsed Radiofrequency

TL;DR

A 71-year-old woman with chronic knee pain after surgery found relief through a treatment targeting the spinal nerve.

Contribution

Demonstrates the effectiveness of DRG-targeted PRF for refractory post-TKR pain.

Findings

Pulsed radiofrequency of the L4 DRG reduced pain by over 70%.

Patient experienced functional improvement and stopped analgesic use.

Radicular pain component was identified through a nerve block test.

Abstract

Persistent pain following total knee replacement (TKR) remains a significant clinical problem and may lead to long-term functional impairment despite technically successful surgery. The underlying mechanisms are often multifactorial and may include neuropathic and referred pain components. We report the case of a 71-year-old woman with severe bilateral knee pain persisting after bilateral TKR, refractory to pharmacologic therapy, physiotherapy, genicular nerve interventions, and peripheral nerve blocks. Ongoing neuropathic features and failure of peripheral treatments raised suspicion of a spinal pain source. A diagnostic left L4 selective nerve root block produced marked but temporary pain relief, supporting a radicular pain component. Subsequent therapeutic pulsed radiofrequency (PRF) of the left L4 dorsal root ganglion (DRG) resulted in sustained pain reduction exceeding 70%, functional improvement, and discontinuation of analgesic medications. This case emphasizes the importance of considering spinal pain generators in refractory post-TKR pain and suggests DRG-targeted PRF as a potential treatment option in appropriately selected patients.

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