Comparison of the efficacy of fluoroscopic guided continuous neuroablative versus pulsed neuromodulative radiofrequency of genicular nerves in patients of osteoarthritis knee

A total of 40 patients will be randomly allocated to either Group-C or Group-P, with 20  patients in each group.Group C (n=20): fluoroscopic guided continuous neuroablative radiofrequency of genicular nerves Group P (n=20): fluoroscopic guided pulsed neuromodulative radiofrequency of genicular nerves.

All patients will be explained about the procedure and positioned in supine position on the fluoroscopy table with the affected leg flexed by 30-40 degrees, using a bolster placed underneath the knee. The procedure will be performed under local anaesthesia at the site of needle insertion and will be given conscious sedation with midazolam 1-2 mg IV and or titrated dose of fentanyl (0.5-1 mcg/kg IV), as and when required. Sterile tray will be prepared constituting sterile gloves, disposable 10 ml syringes, 26 G 3 inch hypodermic needles, connection tubing, and 22 G RF needle. A mixture of ropivacaine and triamcinolone acetonide (7 ml of 0.2% ropivacaine and 80 mg of triamcinolone acetonide) under aseptic precautions will be prepared and will kept on sterile tray. Skin preparation will be done with povidone iodine solution (10%).

C-arm fluoroscope will be subsequently positioned to obtain imaging of knee joint in anteroposterior (AP) and lateral view. The procedure is guided using  fluoroscope and neurostimulation integrated in RF machine (COOLIEF RF GENERATORâ„¢). In the AP fluoroscopic view, the superior lateral and superior medial genicular nerve will be located at the confluence of the lateral and medial femoral shaft and the lateral and medial femoral condyle, respectively. The depth of the needle tip at the midpoint of the femur is further confirmed by  lateral fluoroscopic view.  The inferior medial genicular nerve was located at the confluence of the medial tibial shaft and the tibial flare by AP fluoroscopic view and further the needle tip depth at the midpoint of the tibia will be done by lateral fluoroscopic view.  Local infiltration of 1-2 ml of 2% lignocaine hydrochloride will be injected subcutaneously at each mentioned point of insertion of RF needle. For each genicular nerve, a 10 cm long, 22-G RF needle with a 10-mm active tip will be advanced under fluoroscopy with the assistance of anteroposterior and lateral knee imaging. Final position of the needles will be further confirmed by RF electrode by sensory (50 Hz, up to 1.0 V) and motor (2 Hz, 2.0 V) stimulation.   The settings of CNARF ablation of the target nerve will be carried out at 80°C and 20 V for 90 seconds and PNMRF will be carried out at 42°C and 45V with 3 cycles of 120 seconds at each genicular nerve

Following the RF procedure, 3 ml of sterile solution (7 ml of 0.2% ropivacaine and 80 mg of triamcinolone acetonide) prepared before, was administered at each of three RF lesion site before withdrawing the needle. A sterile dressing will be applied. Patients will be instructed to lie in a supine position after the procedure for next 30 minutes in the recovery room and vitals will be monitored.

Pain assessment of patient by VAS score, Functional improvement of the patient assessed by WOMAC score, Patient satisfaction level by Likert five point scale will be recorded at pre-intervention, 1, 2 and 3 month post-intervention. .