An observational study in Chronic Knee Pain, sponsored by Ziekenhuis Oost-Limburg. Completed at 1 site in Belgium. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-06-14.
Sponsored by Ziekenhuis Oost-Limburg · Observational
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.
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.
Ziekenhuis Oost-Limburg is the lead sponsor of 66 studies on the registry; 17 are open to participants now.
Counted across the registry records on this site, refreshed daily.
All patients with chronic knee pain who qualify for a conventional RF treatment of the genicular nerves can be possible candidated for this retrospective study
Exclusion Criteria:
All patients with chronic knee pain who qualify for a conventional RF treatment of the genicular nerves
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).
Time frame: 6 weeks after treatment
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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).
Time frame: 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.
Time frame: 6 weeks after treatment.
Number of Participants With Post-treatment Complications
Adverse events related to the conventional radiofrequency therapy will be assessed telephonically
Time frame: after retrieval of informed consent, ranging from 6 weeks to 2.5 years after the procedure
September 2017 to June 2020. Patients receiving treatment in Hospital Oost-Limburg, Genk, Belgium.
| Milestone | Conventional Radiofrequency (RF) Treatment |
|---|---|
| Started | 61 |
| Completed | 59 |
| Not completed | 2 |
| Withdrew: Lost to follow-up | 2 |
| Milestone | Conventional Radiofrequency (RF) Treatment |
|---|---|
| Started | 19 |
| Completed | 17 |
| Not completed | 2 |
| Withdrew: Death | 1 |
| Withdrew: Mentally unable to fill in the questionnaire | 1 |
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).
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| The Number of Patients Reaching Treatment Succes at 6 Weeks Defined as Global Perceived Effect (GPE) of ≥ 50% Compared to Baseline. | 4 | 15 |
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.
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| The Number of Participants With NRS Reduction ≥50% Compared to Baseline | 4 | 9 |
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.
| score on a scale | Degenerative Knee Pain | PPSP |
|---|---|---|
| Mean NRS at 6 weeks | 5.6 ± 1.9 | 7.3 ± 1.7 |
| Mean NRS in treatment success group | 2.8 ± 1.5 | 3.4 ± 1.7 |
| Mean NRS in treatment failure group | 7.1 ± 2.4 | 7.5 ± 1.5 |
| Mean NRS at the second time point | 5.3 ± 2.0 | 5.5 ± 1.9 |
| Mean NRS at the second time point in patients with GPE ≥50% | 4.0 ± 0.0 | 3.8 ± 2.2 |
| Mean NRS at the second time point in patients with GPE <50% | 6.0 ± 2.0 | 6.6 ± 0.8 |
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.
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| The Number of Patients With Subjective Increase in Physical Functioning at the Second Time Point | 1 | 6 |
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.
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| Patients on strong opioids | 3 | 8 |
| Patients on strong opioids in treatment success group | 1 | 3 |
| Patients on strong opioids in treatment failure group | 2 | 5 |
The change in use of strong opioids is asked telephonically to the patient.
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| Strong Opioid Use at the Second Time Point | 1 | 5 |
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).
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| The Number of Participants Reaching Treatment Success After Retrieval of the Informed Consent Defined as GPE of ≥ 50% Compared to Baseline. | 2 | 4 |
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.
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| Adverse events | 3 | 6 |
| Severe adverse events | 0 | 1 |
Adverse events related to the conventional radiofrequency therapy will be assessed telephonically
| Participants | Degenerative Knee Pain | PPSP |
|---|---|---|
| Adverse events | 0 | 1 |
| Severe adverse events | 0 | 0 |
Collected over Collection of data happened in a time period that was different for every patient varying from 6 weeks to 2.5 years. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Degenerative Knee Pain | 1/13 (7.7%) | 0/13 (0%) | 3/13 (23.1%) |
| PPSP | 0/46 (0%) | 1/46 (2.2%) | 5/46 (10.9%) |
| Event | Degenerative Knee Pain | PPSP |
|---|---|---|
| Complex regional pain syndrome (CRPS)Nervous system disorders | 0/13 | 1/46 |
| Event | Degenerative Knee Pain | PPSP |
|---|---|---|
| HypoesthesiaNervous system disorders | 1/13 | 3/46 |
| Self-limiting hematomaInjury, poisoning and procedural complications | 1/13 | 0/46 |
| Cracking of the jointMusculoskeletal and connective tissue disorders | 1/13 | 0/46 |
| Instability while walkingMusculoskeletal and connective tissue disorders | 0/13 | 1/46 |
| Increase in painMusculoskeletal and connective tissue disorders | 0/13 | 1/46 |
| Age, Continuous(years) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| Mean | 45.5 ± 15.9 | 66.9 ± 13.9 | 62.6 ± 16.9 |
| Sex: Female, Male(Participants) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| Female | 7 | 33 | 40 |
| Male | 6 | 13 | 19 |
| Race and Ethnicity Not Collected(Participants) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| Count of participants | — | — | 0 |
| Index knee(participants) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| Right | 9 | 18 | 27 |
| Left | 4 | 28 | 32 |
| Patients on strong opioids at baseline consultation(Participants) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| No use of strong opioids | 10 | 33 | 43 |
| Use of strong opioids | 3 | 13 | 16 |
| Mean NRS (± SD) prior to RF treatment(units on a scale.) | Degenerative Knee Pain | Persistent Post-surgical Pain (PPSP) | Total |
|---|---|---|---|
| Mean | 7.8 ± 1.7 | 7.3 ± 1.7 | 7.4 ± 1.8 |
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Ziekenhuis Oost-Limburg