The PERK Study: Predicting and Evaluating Response to Knee RFA Using fNIRS

The goal of this study is collect data for a larger study about using fNIRS to evaluate whether baseline and post-GNRFA cortical activation patterns are associated with clinically meaningful pain relief and improvement in pain-related disability following GNRFA in adults with knee osteoarthritis. While GNRFA is a promising treatment, clinical outcomes remain variable, limiting its widespread adoption. Pain relief following GNRFA may depend not only on anatomically optimized placement, but also on inter-individual differences in central pain processing and modulation reflected in cortical activation patterns. Currently, patient selection for GNRFA is based on response to genicular nerve (GN) blocks, which targets the peripheral sensory innervation. The ability to predict the response to GNRFA from the GN block has been inconsistent. In contrast, fNIRS is a novel, non-invasive and scalable method for assessing cortical activity associated with pain processing and movement-related function. fNIRS may therefore allow clinicians to use cortical activation patterns to select patients most likely to respond to GNRFA, and to objectively quantify response to GNRFA.

This study will have participants complete a combination of in-person visits and remote visits. In-person visits will include fNIRS assessments, questionnaires, the GN block procedure, and the GNRFA procedure if they receive at least 50% pain relief on the GN block. Remote visits will include filling out questionnaires. The questionnaires at all visits will measure pain, mood and quality of life. The primary objective is to obtain preliminary data for estimating effect sizes and informing sample size calculations for a larger study. Secondary objectives including determining whether baseline cortical activation patterns measured using fNIRS is associated with a clinically meaningful treatment response following GNRFA, and to characterize changes in fNIRS activation patterns over time post-GNRFA in responders and non-responders. The results will help determine whether fNIRS may be a feasible, non-invasive way to better select patients to receive GNRFA procedures.