Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Prospective, Multi-Center, RCT Evaluating the Safety and Effectiveness of Coolief™ Cooled Radiofrequency Probe to Create Lesions of the Genicular Nerves and Comparing Corticosteroid Injection in the Management of Knee Pain
Brief Summary: This study is designed to:

* Determine the effectiveness (primarily measured by pain relief) of Coolief when used to create radiofrequency lesions of the genicular nerves compared to pain relief following corticosteroid injection; and
* Confirm the safety of Coolief when used to perform radiofrequency lesions of the genicular nerves in subjects to manage knee pain compared to safety of corticosteroid injection


Options:
A: Inclusion Criteria:

* chronic arthritis according to the American College of Rheumatology criteria
* diagnosed radiologically patients in stage 3 and 4, according to the Kellgren-Lawrence classification

Exclusion Criteria:

* other causes of pain such as radiculopathy, neurological disorders, or intermittent claudication.
* patients receive intraarticular steroid or hyaluronic acids during previous three months.
* patients did previous knee surgery.
* Patients with general contraindication to the application of invasive intervention such as hemorrhage, coagulation disorder, systemic infection or local infection.
* patients with other connective tissue disease affecting the knee. And 6-psychiatric disorders.
B: Inclusion Criteria:

* Clinical diagnosis of primary osteoarthritis of the knee(s)
* Presently receiving prescribed oral or topical analgesics for a minimum duration of two weeks prior to enrollment

Exclusion Criteria:

* Arthritis other than primary osteoarthritis
* Treatment with disease-modifying antirheumatic drugs (DMARDS), methotrexate or biologics
* Subtotal or total joint replacement in the affected knee
* Chronic severe pain of other causes that in the opinion of the investigator may require long-term analgesia or confound the present study
* Currently enrolled in a clinical trial or who have participated in a clinical trial within the past 30 days
C: INCLUSION CRITERIA

1. Age ≥ 21 years
2. Able to understand the informed consent form and provide written informed consent and able to complete outcome measures
3. History of chronic knee pain for longer than 6 months unresponsive to conservative treatments (PT, oral analgesics, intra-articular injections with steroids and/or viscosupplementation)
4. Positive response (defined as a decrease in numeric pain scores of at least 50%) to a geniculate nerve block of the index knee
5. Pain on NRS ≥ 6 on a 10 point scale for the index knee
6. Radiologic confirmation of osteoarthritis (x-ray/MRI/CT) of OA grade of 2 (mild), 3 (moderate) or 4 (severe) noted within 12 months for the index knee
7. Oxford Knee Score group at Baseline of ≤ 35 indicating moderate to severe OA in the index knee
8. If the patient is taking an opioid or other morphine equivalent medication, the dose must be considered clinically stable (defined as \<10% change in dosage for ≥ 2 months prior to the screening visit).
9. Analgesics including membrane stabilizers such as Neurontin and antidepressants for pain such as Cymbalta must be clinically stable (defined as stable dosage for ≥ 6 weeks prior to the screening visit) and shall not change during the course of the study without approval of investigator. Agree to see one pain doctor (study investigator) for knee pain during the study period
10. Index knee pathology that is consistent with generally accepted indications for total knee arthroplasty.
11. Willing to delay any surgical intervention for the index knee for 12 months.
12. Willingness to provide informed consent and to comply with the requirements of this protocol for the full duration.

EXCLUSION CRITERIA

1. Pseudo arthritis, rheumatoid arthritis or other systemic inflammatory arthritis condition that could cause knee pain.
2. Previous or pending lower limb amputation.
3. Intra-articular steroid, platelet rich plasma (PRP) or hyaluronic acid injections in the index knee within 90 days from the screening visit.
4. An intra-articular corticosteroid injection is not indicated as an appropriate treatment option.
5. Prior radiofrequency of the genicular nerves of the index knee.
6. Prior partial, resurfacing, or total knee arthroplasty in index knee.
7. Clinically significant ligamentous laxity of the index knee.
8. Evidence of structural abnormality other than osteoarthritis of knee, hip or back that materially affects gait or function of the knee or is the underlying cause of the knee pain.
9. BMI \> 40.
10. Extremely thin patients and those with minimal subcutaneous tissue thickness that would not accommodate a lesion of up to 14 mm in diameter to limit the risk of skin burns.
11. Pending or active compensation claim, litigation or disability remuneration (secondary gain) related to knee.
12. Pregnant or intent of becoming pregnant during the study period.
13. Chronic pain associated with significant psychosocial dysfunction.
14. Beck's Depression Index score of \> 22 (indicates clinically depressed state).
15. Allergies to any of the medications to be used during the procedure.
16. Systemic or localized infection at needle entry sites (subject may be considered for inclusion once infection is resolved).
17. History of uncontrolled coagulopathy, ongoing coagulation treatment or unexplained or uncontrollable bleeding that is uncorrectable.
18. Identifiable anatomical variability that would materially alter the procedure as described in the protocol.
19. Within the preceding 2 years, subject has suffered from active narcotic addiction, substance or alcohol abuse.
20. Current prescribed opioid medications equivalent to greater than 60 morphine equivalent daily opioid dose.
21. Uncontrolled immunosuppression (e.g. AIDS, cancer, diabetes, etc.)
22. Subject currently implanted with pacemaker or defibrillator.
23. Participating in another clinical trial/investigation within 30 days prior to signing informed consent.
24. Subject unwilling or unable to comply with follow up schedule or protocol requirements.
D: Inclusion Criteria:

* Signed written informed consent must be obtained before any study assessment is performed.
* Adult patients (Age ≥ 18 years old).
* Chronic anterior knee pain (\> 12 months) that is moderate to severe (defined as NRS \> 4 on most or all days for the index knee either constantly or with motion at time of screening and, an average NRS score reported in the patient diary \>4 at the end of the run-in period).
* Unresponsive (meaning insufficient pain reduction or intolerance) to conventional treatments ongoing for at least 12 months prior to inclusion. Conventional treatments must include all of the following: active physiotherapy, pharmacological treatment of pain and intra-articular corticosteroid infiltration.
* Only for patients with Osteoarthritis (OA): Radiologic confirmation of knee osteoarthritis of grade 2 (mild), 3 (moderate) or 4 (severe) noted within 12 months prior to the screening for the index knee according the Kellgren Lawrence criteria diagnosed by an independent radiologist with experience in musculoskeletal imaging on radiography (Rx) or magnetic resonance imaging (MRI). If imaging will need to be performed at screening it is recommended to perform an MRI instead of Rx. Imaging with MRI will enable the independent radiologist to perform a better estimation of the grade of OA.
* Only for patients with Persistent Post-Surgical Pain (PPSP) after Total Knee Arthroplasty (TKA): Patients with PPSP\* after TKA need to have had a negative orthopaedic work-up

Exclusion Criteria:

* Local or systemic infection (bacteraemia).
* Evidence of inflammatory arthritis or an inflammatory systemic disease responsible for knee pain.
* Intra-articular injections (steroids, hyaluronic acid, platelet enriched plasma, ...) in the index knee during the 3 months prior to procedure.
* Pregnant, nursing or planning to become pregnant before the study intervention. Participants who become pregnant after the study intervention during the follow-up period will not be excluded.
* Chronic widespread pain.
* Patients with unstable psychosocial disorder.
* Allergies to products used during the procedure (lidocaine, propofol, chlorhexidine).
* Uncontrolled coagulopathy defined as supratherapeutic dose of anticoagulation medication.
* Uncontrolled immune suppression.
* Participating in another clinical trial/investigation within 30 days prior to signing informed consent.
* Patient is currently implanted with a neurostimulator.
* Current radicular pain in index leg.
* Previous conventional or cooled radiofrequency of the index knee.
* Patients with bilateral knee pain defined as chronic knee pain (\> 12 months) in both knees that is moderate to severe (defined as a numeric rating scale (NRS) \> 4 on most or all days either constantly or with motion) and that is unresponsive (meaning insufficient pain reduction or intolerance) to conventional treatments ongoing for at least 12 months prior to inclusion. Conventional treatments must include all of the following: active physiotherapy, pharmacological treatment of pain and intra-articular corticosteroid infiltration.
* Patients who have a planned TKA in the near future defined as patients who already have agreed on a date for the TKA procedure.
* Patients who are unwilling or mentally incapable to complete the study questionnaires.

Answer: C