Phenol Neurolysis of Genicular Nerves for Chronic Knee Pain

Study Overview
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Brief Summary
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Chronic knee pain from osteoarthritis (OA) is commonly treated with total knee arthroplasty (TKA) when conservative therapies fail to provide pain relief. More than 600,000 TKAs are performed in the U.S. annually, a number that continues to increase. A logistic-regression model suggests that the incidence rate of TKA will increase by 143% in the United States by 2050 compared to 2012. Although TKA is successful in reducing knee pain and joint stiffness in most cases, it can be associated with a 7-35% incidence of persistent refractory post-surgical knee pain. Aim: To determine whether chemical neurolysis of the genicular nerves with 6% aqueous phenol is non-inferior in reducing knee pain as compared to corticosteroid injection of the genicular nerves, in patients with refractory chronic knee pain for more than 6 months after total knee replacement. Hypothesis: Chemical neurolysis of genicular nerves with phenol will provide equal or superior pain relief than corticosteroid genicular nerve injections at 3 months, as measured by the Oxford Knee Score.

Official Title
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Phenol Neurolysis of Genicular Nerves for Chronic Knee Pain Following Total Knee Arthroplasty: a Pilot Prospective, Randomized, Crossover Trial

Conditions
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Pain, Chronic

Intervention / Treatment
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* Drug: Phenol Injection
* Drug: Methylprednisolone Injection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 40-95 years Patients with knee pain, on average > 4 (NRS) persisting more than 6 months after TKA Willingness to undergo image guided diagnostic nerve block and the study intervention Exclusion Criteria: Pain score (NRS) < 4 at time of study enrollment Conditions that preclude the diagnostic block or the study intervention (e.g., irreversible coagulopathy or bleeding disorder, allergic reaction/contraindication to local anesthetic, contrast dye, steroids, and/or phenol, pregnancy, severe or uncontrolled medical illness). Evidence of indolent infection of the knee prosthesis (elevated C-reactive protein assessed when clinically indicated) Inability to write, speak, or read in English Pregnancy

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: A Pilot Prospective, Randomized, Crossover Trial. (Block randomization scheme with 2:1 allocation (phenol neurolysis : perineural steroid injection) The crossover will occur in subjects who received the steroid injection who did not achieve adequate pain relief at 3 months.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Treatment Group: Phenol injection<br>6% aqueous phenol 2.5 mL will be mixed with 0.5 mL iopamidol 300 and will be injected at each target sites | Drug: Phenol Injection<br>* 6% aqueous phenol 2.5 mL will be mixed with 0.5 mL iopamidol 300 and will be injected at each target site with live, pulsed fluoroscopy (5-8 seconds at each location) to observe the contrast dye-tagged phenol covering the lateral margin of the femur or tibia respectively on AP and lateral views. The needles will then be removed and band-aids placed.<br>* Other names: Phenol;|
| Other: Control Group: Methylprednisolone injection<br>Methylprednisolone acetate 10 mg with 2 mL preservative free saline and 0.5 mL iopamidol 300 will be injected at each of the target site | Drug: Methylprednisolone Injection<br>* Methylprednisolone acetate 10 mg with 2 mL preservative saline and 0.5 mL iopamidol 300 will be injected at each of the 3 target sites with live, pulsed fluoroscopy (5-8 seconds at each location) to observe the contrast dye-tagged steroid mixture covering the lateral margin of the femur or tibia respectively on AP and lateral views; the needles will be removed and band-aids placed.<br>* Other names: Methylprednisolone acetate;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxford Knee Score | Oxford Knee Score is a tool which measures 6 post operative items (pain,flexion contracture, extension lag, total range of flexion, alignment of varus and valgus,stability (antero-posterior and mediolateral). The scoring is: below 60 is poor, scoring 60-69 fair, scoring 70-79 good, 80-100 excellent. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Numeric Rating Scale Score | The proportion of subjects who have > 50% reduction in pain based on the Numeric Rating Scale at 3 months. The NRS is a scale of 0 (no pain) to 10 (worst pain imaginable) | 3months | 
| Numeric Rating Scale Score | The proportion of subjects who have > 50% reduction in pain based on the Numeric Rating Scale at 6 months. The NRS is a scale of 0 (no pain) to 10 (worst pain imaginable) | 6 months | 
| Patients Global Impression of Change | Patients Global Impression of Change (GPIC) is a scale of 0 (much better) to 10 (much worse) | 3 Months | 
| Patients Global Impression of Change | Patients Global Impression of Change (GPIC) is a scale of 0 (much better) to 10 (much worse) | 6 Months | 
| Opioid analgesic use at 3 months | Opioid analgesic daily use by self reporting . | 3 months | 
| Opioid analgesic use at 6 months | Opioid analgesic daily use by self reporting. | 6 months | 
| Non-opioid analgesic use at 3 months | Non opioid analgesic daily use by self reporting. | 3 Months | 
| Non-opioid analgesic use at 6 months | Non opioid analgesic daily use by self reporting. | 6 Months | 
| PROMIS Pain Intensity Short Form 3a | 3 question pain survey. 5 responses (had no pain),(mild), (moderate), (severe) and (very severe) | Baseline | 
| PROMIS Pain Intensity Short Form 3a | 3 question pain survey. 5 responses (had no pain),(mild), (moderate), (severe) and (very severe) | 3 Months | 
| PROMIS Pain Intensity Short Form 3a | 3 question pain survey. 5 responses (had no pain),(mild), (moderate), (severe) and (very severe) | 6 Months | 
| PROMIS Sleep Disturbance Short Form 4a | 4 question sleep survey. First section is quality of sleep rated on a 5 response (very poor)- (very good) scale.Section rating quality of sleep based on 5 response choices (not at all) to (very much) | Baseline | 
| PROMIS Sleep Disturbance Short Form 4a | 4 question sleep survey. First section is quality of sleep rated on a 5 response (very poor)- (very good) scale.Section rating quality of sleep based on 5 response choices (not at all) to (very much) | 3 Months | 
| PROMIS Sleep Disturbance Short Form 4a | 4 question sleep survey. First section is quality of sleep rated on a 5 response (very poor)- (very good) scale.Section rating quality of sleep based on 5 response choices (not at all) to (very much) | 6 Months | 
| PROMIS Pain Interference Short Form 6b | 6 question pain survey. First section is interference of pain rated on a 5 response (not at all)- (very much) scale. Section is one socialization question with 5 response choices (never)- (always) | Baseline | 
| PROMIS Pain Interference Short Form 6b | 6 question pain survey. First section is interference of pain rated on a 5 response (not at all)- (very much) scale. Section is one socialization question with 5 response choices (never)- (always) | 3 Months | 
| PROMIS Pain Interference Short Form 6b | 6 question pain survey. First section is interference of pain rated on a 5 response (not at all)- (very much) scale. Section is one socialization question with 5 response choices (never)- (always) | 6 Months | 
| Oxford Knee Score | 12 question survey with 5 choice responses based on severity of pain while accomplishing activities of daily living. | Baseline | 
| Oxford Knee Score | 12 question survey with 5 choice responses based on severity of pain while accomplishing activities of daily living. | 6 Months | 
| Hospital Anxiety and Depression Scale | Hospital Anxiety and Depression Scale (HADS) is a 14 question survey (7 anxiety and 7 depression) questions answered on a 0 (low) - 3 (high) scale.Total score of 0-7 is normal, 8-10 is baseline abnormal and a score between 11-21 is abnormal. | Baseline | 
| Hospital Anxiety and Depression Scale | Hospital Anxiety and Depression Scale (HADS) is a 14 question survey (7 anxiety and 7 depression) questions answered on a 0 (low) - 3 (high) scale.Total score of 0-7 is normal, 8-10 is baseline abnormal and a score between 11-21 is abnormal. | 3 Month | 
| Hospital Anxiety and Depression Scale | Hospital Anxiety and Depression Scale (HADS) is a 14 question survey (7 anxiety and 7 depression) questions answered on a 0 (low) - 3 (high) scale. Total score of 0-7 is normal, 8-10 is baseline abnormal and a score between 11-21 is abnormal. | 6 Month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Total knee arthroplasty, Chronic Pain