FRI0382 EFFECTS OF GENICULAR NERVE BLOCK IN PATIENTS WITH KNEE OSTEOARTHRITIS WHO HAVE NEUROPATHIC OR NOCICEPTIVE PAIN

Abstract

Background: Genicular nerve block (GNB) is a safe and effective therapeutic procedure for intractable pain associated with chronic knee osteoarthritis (OA) (1). There is increasing support for the neuropathic component to the knee OA pain. Investigators proposed that targeting treatment to the underlying pain mechanism can improve pain management in knee OA (2). There is a debate on injectable solutions used in nerve blocks (3). Objectives: To investigate the analgesic and functional effects of USG‐guided GNB in patients with chronic knee OA (with/without neuropathic pain) and to evaluate the efficacy of the anesthetic and non‐anesthetic solutions used. Methods: Ninety patients with chronic knee OA between the ages of 50‐80 were divided into two groups with and without neuropathic pain according to painDETECT questionnaire (4). The groups were randomized into three subgroups to either the lidocaine group (n=30) or dextrose group (n=29) or saline solutions (n=31). After the ultrasound‐guided GNB, quadriceps isometric strengthening exercises and cryotherapy were recommended to the patients. Visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Lequesne‐algofunctional Index were assessed at baseline and at 1 week, 1 and 3 months later after the procedure. Results: Statistically significant improvement was observed in all groups with or without neuropathic pain according to VAS values at the 1st week, 1st month and 3rd month compared to baseline (p<0.05). Statistically significant improvement was observed in all groups with neuropathic pain according to painDETECT values at the 1st week, 1 st month and 3rd month compared to baseline (p<0.05). There was a statistically significant improvement in the groups without neuropathic pain which received dextrose and saline solutions, according to painDETECT values, but not in the group which received lidocain at the 1st week, 1st month and 3rd month compared to baseline (p>0.05). There was a statistically significant improvement in all groups with or without neuropathic pain according to WOMAC and Lequesne total scores at the 1st week, 1st month and 3rd month compared to baseline (p<0.05). Conclusion: We conclude that in patients with chronic knee OA (with/without neuropathic pain), the use of GNB with USG is an analgesic method which provides short to medium term analgesia and functional recovery and has no serious side effects. The lack of significant difference between the anesthetic and non‐anesthetic solutions used in the GNB suggests that this may be a central effect rather than a symptom of peripheral nerve dysfunction. It suggests that injection may have an indirect effect through nociceptive processing and changes in neuroplastic mechanisms in the brain. In addition, we can say that regular exercise program contributes to improved physical function with the decrease in pain.