Comparison of Conventional and Cooled Radiofrequency of the Genicular Nerves in Patients With Chronic Knee Pain

ConditionsKnee Osteoarthritis Persistent Postsurgical Pain Chronic Knee Pain

Trial statusRecruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18+

SponsorZiekenhuis Oost-Limburg

About this trial

Chronic knee pain remains a disabling disease despite current treatment strategies. There is an increase in the prevalence of osteoarthritis (OA) of the knee in the general population, presently affecting approximately 450,000 individuals in Belgium. A total knee replacement is a viable alternative for severe knee OA that does not respond to conservative therapy. Unfortunately, up to 53% of patients who undergo a total knee replacement develop persistent post-surgical pain (PPSP). There is currently no effective therapy for PPSP.

A radiofrequency (RF) treatment applies high frequency current on the nerve responsible for pain conduction, resulting in an interruption of the transmission of pain. This can be applied to the nerves innervating the knee joint - the superolateral, superomedial and inferomedial genicular nerves - and could be an alternative, minimally invasive treatment for patients with knee OA who fail conservative treatments and for patients with PPSP. Data from the recent literature indicates that this treatment leads to a reduction of pain intensity and could result in an improvement of knee function, of the psychological state of the individual, and finally in an increase in health-related quality of life. Furthermore, RF of the genicular nerves could help avoid or delay a total knee replacement therefore potentially contributing to cost reduction. Both cooled and conventional RF treatments are reported in the literature to improve pain. The use of water to cool the RF electrodes results in an increased lesion size by removing heat from adjacent tissue, allowing power delivery to be increased. As a consequence, cooled RF could result in a higher chance of success and longer duration of effect. Until now, the studies performed on cooled RF are industry initiated and a direct comparison between conventional, cooled and a sham procedure is lacking.

The aim of the COGENIUS trial is to investigate the effect of the two types of RF treatment on individuals experiencing chronic knee pain that is resistant to conservative treatments. For this purpose, the efficacy and cost-effectiveness of cooled and conventional RF will be compared to a sham procedure in patients suffering from knee OA and PPSP after total knee replacement.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

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.

Disqualifiers

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.

Trial design

Design model

Parallel

Treatments tested in this trial

Conventional Radiofrequency ablation of the genicular nerves
Procedure/Surgery
Conventional Radiofrequency treatment of the genicular nerves of the knee blocks the transmission of painful stimuli from the sensory genicular nerves of the knee to the central nervous system by means of a thermal lesion created using RF current.
Cooled Radiofrequency ablation of the genicular nerves
Procedure/Surgery
Cooled RF treatment causes a larger lesion size compared to conventional RF by means of internal cooling of the probe.
Sham procedure
Procedure/Surgery
Sham procedure with placing of needles subcutaneously.

Treatment groups

400 Participants

are divided into 3 treatment groups

Group A: Conventional Radiofrequency of the genicular nervesActive comparator 1 intervention

Group B: Cooled Radiofrequency of the genicular nervesActive comparator 1 intervention

Group C: Sham procedureSham comparator 1 intervention

Trial outcomes

Primary outcomes

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 6 months post-intervention

The primary endpoint is the WOMAC score (range 0-96) at 6 months post-intervention. The WOMAC score is derived from a self-administered osteoarthritis-specific validated questionnaire on pain, stiffness, and physical functioning of the knee joint.The lower the score, the lower the osteoarthritis-specific symptoms are.

Time frame

6 months post-intervention.

Secondary outcomes

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score.

The WOMAC score (range 0-96) is derived from a self-administered osteoarthritis-specific validated questionnaire on pain, stiffness, and physical functioning of the knee joint.The lower the score, the lower the osteoarthritis-specific symptoms are.

Time frame

1-, 3-, 6-, 12- and 24-months post-intervention.

Pain Intentisty

Pain intensity expressed by the Numerical Rating Scale (NRS) (range 0-10). The NRS score at each visit will be calculated as the mean score of the 4 days prior to each visit.The lower the score, the least pain the patient experiences.

Time frame

1-, 3-, 6-, 12- and 24-months post-intervention.

The proportion of patients with a pain reduction of at least 50% compared to baseline expressed by the numerical rating scale (NRS)

The proportion of patients with a pain reduction of at least 50% compared to baseline expressed by the numerical rating scale (NRS) (0-10). The NRS score at each visit will be calculated as the mean score of the 4 days prior to each visit.The lower the score, the least pain the patient experiences.

Time frame

1-, 3-, 6-, 12- and 24-months post-intervention.

Health-related quality of life

Health-related quality of life assessed by the EuroQoL-5D-5L (EQ-5D-5L). The questionnaire consists of 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression and a visual assessment scale. Responses to the 5 items (one for each dimension) result in a patient's health state that can be transformed into a utility score ranging between 0 (death) and 1 (full health), representing the quality of life of the health state. For the visual assessment scale section, the patient indicates their impression of health on the visual scale. The scale has the following distribution: 0 indicating "worse possible health" and 100 indicating "best possible health".

Time frame

1-, 3-, 6-, 9-, 12- and 24-months post-intervention.

Other outcomes

Phenotype of patients suffering from Persistent Post-Surgical Pain (PPSP)

Demographic data collected at baseline will be used to phenotype patients suffering from PPSP.

Time frame

Baseline

Time to additional interventions

Time to additional interventions at each time point. Interventions will be divided in minimally invasive interventions (intraarticular (IA) steroid injections, IA hyaluronic acid, platelet rich plasma of infiltrations, repeat RF of the genicular nerves) and surgery (primary/revision total knee arthroplasty and other knee related surgery) during the follow-up.

Time frame

Follow-up until 24-months post- intervention.

Locations15

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