Functional Outcome and Pain Relief After Pulsed Radiofrequency of Saphenous Nerve in Medial Compartment Knee Osteoarthritis: A Randomised Double-Blind Trial

Abstract

Background and aims: Pulsed radiofrequency (PRF) of saphenous nerve (SN) has shown effective pain relief in knee pain due to knee osteoarthritis (KOA). Since adductor canal (AC) contains other sensory nerves innervating the medial part of knee joint apart from SN. We compared the PRF of SN within and outside the AC for their quality and duration of pain relief in knee osteoarthritis of medial compartment (KOA-MC). Methods: We conducted a randomised prospective study in 60 patients with anteromedial knee pain due to KOA-MC. Patients in group A received PRF-SN and those in group B, PRF-AC. Primary objectives were, comparison of pain by visual analogue scale (VAS) score and changes in quality of daily living by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and OXFORD knee scores (OKS). Secondary objectives were, comparison of analgesic requirements using Medicine Quantification Scale (MQS) scale and block related complications. Intra group comparison was done by Analysis of variance (ANOVA). Inter group normally distributed data was assessed by student's t-test, non-normally distributed and ordinal data by Mann-Whitney U-test and categorical data by Chi-square test. A p value of < 0.05 was considered significant. Results: VAS scores were significantly lower in Gr-B at 12 weeks. The WOMAC scores and OXFORD scores at 4, 8, 12 and 24 weeks were significantly lower in Gr-B compared to Gr-A. Conclusion: The PRF-AC provides better pain relief and functional outcome than PRF-SN however, duration of pain relief was not significantly different.