The study is designed to evaluate and compare the efficacy of three needles approach as a new technique in radiofrequency neurotomy of genicular nerve versus the traditional single needle approach as a treatment of advanced knee osteoarthritic pain. Primary outcome:

1. Pain intensity via the visual analogue score (VAS).
2. Function and pain via the Oxford Knee Score. Evaluated after 6 months of the procedure

Secondary outcome:

1. Failure rate.
2. Incidence of any complication.
3. Total analgesic requirement during the period of follow up.

Inclusion Criteria:

• 1- Age 35-85 years old 2- Patients with stage 3 or higher OA-related radiological changes based on Kellgren-Lawrence (K/L) rating scale 3- Knee pain for at least 3 months 4-Patients are clinically unresponsive to conservative treatment modalities (physical therapy and rehabilitation practices, orally administered analgesics and anti-inflammatory drugs).

Exclusion Criteria:

• 1- Patients with other causes of pain as radiculopathy, neurological disorders or intermittent claudication. 2- Previous knee trauma. 3- Previous knee surgery. 4- Patients received intra-articular injection during the previous three months.

  5- Acute knee pain. 6- Crystal arthropathy. 7- Joint effusion. 8- Serious neurological or psychiatric disorders. 9- On anticoagulant medication. 10- Any other connective tissue disorder that affects the knee joint. 11- skin infection at the site of injection. 12-patient refusal.