This observational cohort study aims to evaluate the clinical effect of adding ultrasound-guided pulsed radiofrequency treatment of the distal superficial and deep sensory branches of the nerve to vastus medialis to conventional genicular nerve radiofrequency treatment in patients with chronic knee pain due to knee osteoarthritis.

Adult patients aged 45-80 years with clinically and radiologically confirmed knee osteoarthritis and chronic knee pain lasting at least 3 months despite conservative treatment will be included. Patients will be followed according to routine clinical practice. Two cohorts will be evaluated: patients treated with conventional genicular nerve radiofrequency alone and patients treated with conventional genicular nerve radiofrequency plus pulsed radiofrequency of the distal sensory branches of the nerve to vastus medialis.

Pain intensity will be assessed using the Visual Analog Scale, and functional status will be evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index. Assessments will be performed before the procedure, at 1 month, and at 3 months after treatment. Adverse events recorded in patient files will also be evaluated.

Chronic knee pain related to knee osteoarthritis is mediated by a complex sensory innervation network. Although genicular nerves are commonly targeted in radiofrequency procedures for knee osteoarthritis pain, recent anatomical and ultrasound-based studies suggest that additional sensory branches may contribute to medial knee joint pain. The distal sensory branches of the nerve to vastus medialis have been described as contributors to the sensory innervation of the medial knee joint capsule.

In routine clinical practice, patients with chronic knee pain due to knee osteoarthritis may undergo ultrasound-guided conventional radiofrequency treatment of the genicular nerves. In some patients, pulsed radiofrequency treatment targeting the distal superficial and deep sensory branches of the nerve to vastus medialis may also be added. This study will compare clinical outcomes between these two routinely treated cohorts.

The study will include adult patients aged 45-80 years with knee osteoarthritis confirmed clinically and radiologically, Kellgren-Lawrence grade II-IV, chronic knee pain lasting at least 3 months, and insufficient response to conservative treatments. The primary outcome will be the change in pain intensity measured by the Visual Analog Scale from baseline to follow-up. Functional outcomes will be assessed using the WOMAC score. Evaluations will be performed at baseline, 1 month, and 3 months after the procedure. Safety outcomes will include procedure-related adverse events such as hematoma, infection, increased neuropathic pain, or transient motor impairment.

No additional intervention will be performed for research purposes, and treatment allocation will not be determined by the investigators.

Inclusion Criteria:

Age between 45 and 80 years Clinical and radiological diagnosis of knee osteoarthritis Kellgren-Lawrence grade II-IV knee osteoarthritis Chronic knee pain lasting at least 3 months Insufficient response to conservative treatments such as NSAIDs, physical therapy, or exercise programs Baseline Visual Analog Scale pain score ≥5 No coagulation disorder or active infection that would contraindicate the procedure Written informed consent provided by the participant

Exclusion Criteria:

Knee pain primarily caused by conditions other than osteoarthritis, including inflammatory arthritis, septic arthritis, tumor-related causes, or infectious causes Previous total knee arthroplasty or knee prosthesis surgery in the affected knee Radiofrequency or neurolytic procedure around the affected knee within the last 6 months Severe knee instability, advanced deformity, or history of acute trauma Active infection, skin lesion, or ulceration at the procedure site Uncontrolled systemic disease such as advanced heart failure or uncontrolled diabetes Bleeding diathesis or inability to discontinue anticoagulant therapy for an appropriate duration Pregnancy or lactation Cognitive impairment, inability to cooperate, or inability to comply with follow-up visits

The study population will consist of adult patients aged 45 to 80 years with clinically and radiologically confirmed knee osteoarthritis and chronic knee pain lasting at least 3 months despite conservative treatment. Eligible patients will be those who are evaluated in the Algology Clinic and undergo ultrasound-guided genicular nerve radiofrequency treatment, with or without additional pulsed radiofrequency treatment targeting the distal sensory branches of the nerve to vastus medialis, as part of routine clinical practice. Patients will be included after providing written informed consent and will be followed for pain and functional outcomes at baseline, 1 month, and 3 months after the procedure.