Patients With Chronic Knee Pain Treated With Conventional Radiofrequency of the Genicular Nerves

Study Overview
=================
Brief Summary
-----------------
Management of chronic knee pain remains a challenge to the treating physician. A radiofrequency treatment of the genicular nerves is a not yet established but promising technique. This procedure is minimal invasive and has few adverse events. For these reasons it can be advantageous and fulfilling the unmet needs of these chronic knee pain patients warranting further research of its efficacy. To investigate this efficacy, all patients treated with radiofrequency ablation in the multidisciplinary chronic pain center between 1 September 2017 and 31 December 2019 with exclusion of patients with chronic widespread pain, will be retrospectively analyzed in a single-center cohort.

Detailed Description
-----------------
This project has as primary objective the evaluation of treatment success of a conventional radiofrequency treatment of the genicular nerves in patients diagnosed with chronic knee pain due to osteoarthritis of the knee or persistent post-surgical pain (PPSP) at six weeks post treatment. Secondary objectives are evaluation of treatment effect at a third time point at the end of the inclusion period, subgroup analysis of treatment success based on indication to treatment, evaluation of subjective functional improvement and change in analgesics, estimation of the duration of effect of the treatment and adverse events. This study includes all patients treated with radiofrequency ablation in the multidisciplinary chronic pain center in Ziekenhuis Oost-Limburg, Campus Sint-Barbara between 1 September 2017 and 31 December 2019 with exclusion of patients with chronic widespread pain. The main study outcome is the proportion of patients with a global perceived effect of at least 50% at 6 weeks post intervention. Secondary outcomes include reduction in pain intensity, measured by Numeric Rating Scale (NRS) at six weeks and at a third time point, global perceived effect at a third time point, subjective change in physical functioning, duration effect of the treatment, use of strong opioids, and adverse events.

Official Title
-----------------
A Retrospective Single-center Cohort Study on Patients With Chronic Knee Pain Treated With Conventional Radiofrequency of the Genicular Nerves

Conditions
-----------------
Chronic Knee Pain

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: All patients with chronic knee pain who qualify for a conventional RF treatment of the genicular nerves Exclusion Criteria: A negative diagnostic block with lidocaine 2% 1 ml of the three genicular nerves defined as less than 50% pain reduction Chronic widespread pain

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Conventional radiofrequency (RF) treatment<br>All patients with chronic knee pain who qualify for a conventional RF treatment of the genicular nerves | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Number of Patients Reaching Treatment Succes at 6 Weeks Defined as Global Perceived Effect (GPE) of ≥ 50% Compared to Baseline. | Treatment success is defined as a global perceived effect (GPE) of at least 50% at measurement time point compared to baseline. Global perceived effect (GPE) scales are used as an overall outcome measure for patients with pain, as they may cover additional aspects to pain relief and physical function that are important to the individual. Patients are asked to response on the question of how the treatment influenced the pain symptoms. The patients were asked to expres their answer in percentage where 0 % ( no improvement) to 100 (total improvement, the symptoms are gone). | 6 weeks after treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The Number of Participants With NRS Reduction ≥50% Compared to Baseline | The numeric rating scale (NRS) is used to assess pain intensity varying from 0 (no pain) to 10 (intense pain). This scale was retrieved retrospectively out of the patient file. NRS reduction ≥50% is calculated using the NRS at 6 weeks compared to the NRS at baseline. | 6 weeks after treatment | 
| The Patient's NRS | The numeric rating scale (NRS) is used to assess pain intensity varying from 0 (no pain) to 10 (intense pain). This scale will be asked telephonically to the patient. | after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure | 
| The Number of Patients With Subjective Increase in Physical Functioning at the Second Time Point | The question 'Do you experience at the moment functional improvement in comparison with before the treatment?' is asked telephonically to the patient. The possible answers are 'no increase in physical functioning' and ' yes, there was an increase in physical funcitoning'. An increase in physical functioning is the best outcome. | after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure | 
| The Number of Pariticipants Using Strong Opioids | The change in use of strong opioids is retrieved retrospectively out of the patient file. The answer to the use of strong opioids is yes or no. No use of strong opioids is a better outcome. | 6 weeks after treatment | 
| Strong Opioid Use at the Second Time Point | The change in use of strong opioids is asked telephonically to the patient. | after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure | 
| The Number of Participants Reaching Treatment Success After Retrieval of the Informed Consent Defined as GPE of ≥ 50% Compared to Baseline. | Treatment success is defined as a global perceived effect (GPE) of at least 50% at measurement time point compared to baseline. Global perceived effect (GPE) scales are used as an overall outcome measure for patients with pain, as they may cover additional aspects to pain relief and physical function that are important to the individual. Patients are asked to response on the question of how the treatment influenced the pain symptoms. The patients were asked to expres their answer in percentage where 0 % ( no improvement) to 100 (total improvement, the symptoms are gone). | after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure | 
| Number of Participants With Post-treatment Complications | Adverse events related to the conventional radiofrequency therapy will be assessed. This will be assessed retrospectively in the patient file according to the standard of care consultation at 6 weeks after treatment. | 6 weeks after treatment. | 
| Number of Participants With Post-treatment Complications | Adverse events related to the conventional radiofrequency therapy will be assessed telephonically | after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Conventional radiofrequency