Pulsed Radiofrequency Energy to Treat Post-Bunionectomy Pain

Pre-operative Inclusion Criteria:

• Adults aged 18-75 years old
• Subject is scheduled to undergo primary, unilateral first metatarsal bunionectomy (no collateral procedures) under regional/local anesthesia and sedation
• Subject meets the criteria for American Society of Anesthesiologists (ASA) Physical Status I or II.
• Subject is willing to be confined at the investigative site for approximately 4 days including the day of surgery.
• Subject is able to communicate meaningfully in English in order to complete study assessments and comply with all trial procedures.
• Willingness to give written informed consent and to comply with all parts of the study protocol.
• Female Subjects of child bearing potential are eligible only if they are not pregnant (negative pregnancy test at screening and before surgery), not lactating, and not planning to become pregnant during the study.
• Female Subjects must be post-menopausal, surgically sterile, abstinent, or practicing, or agree to practice, an effective method of birth control if they are sexually active for the duration of the study (effective methods of birth control include prescription hormonal contraceptives, intrauterine devices, double-barrier methods, and/or male partner sterilization).

Pre-Operative Exclusion Criteria:

• Subject is scheduled to undergo Base wedge osteotomy, and/or Long-Z Hart bunionectomy procedure or any other procedure that does not conform to the surgical protocol.
• Subject has received any investigational drug within 1 month prior to the Screening Visit or is enrolled in another clinical trial.
• Subject has a history of drug abuse within 5 years of the screening visit, including a history of opioid (narcotic) analgesic abuse.
• Subject has a history of any clinically significant cardiac, respiratory (except mild asthma), renal, hepatic, gastrointestinal, hematologic, endocrine or psychiatric disease or disorder, or any uncontrolled medical illness that in the investigator's judgment places the Subject at unacceptable risk for surgery or receipt of investigational therapy.
• Subject has an ongoing, uncontrolled painful condition that in the opinion of the Investigator might have a confounding influence on the safety or efficacy analysis for this study.
• Subject has received systemic corticosteroid administration within 1 month prior to surgery or is scheduled to receive systemic corticosteroid therapy at any time during the course of the study.
• Subject is unwilling to abstain from alcohol from at least midnight the night before surgery through completion of all In-patient Treatment Period procedures and discharge from the investigative site.
• Subject is unwilling to refrain from smoking during his/her stay at the investigative site.
• Subject is currently receiving treatment, or has received treatment within the last two weeks, with antipsychotic drugs, monoamine oxidase inhibitors, duloxetine, gabapentin, carbamazepine, phenytoin, pregabalin or is receiving treatment with antidepressants that are not on a stable dose (the same dose for >1 month).
• Subject has a history of malignancy within the past five years with the exception of successfully treated non-metastatic basal cell or squamous cell carcinomas of the skin and/or localized carcinoma in situ of the cervix.
• Subject has current evidence of alcohol abuse (regularly drinks more than four units of alcohol per day; 1 unit = ½ pint of beer, 1 glass of wine, or 1 ounce of spirit).
• Infection (acute or chronic) involving the first metatarsal (or history of such infection) or any other disease of the foot/ankle that in the opinion of the investigator, places the Subject at increased risk for surgical complications or receipt of the investigational therapy.
• Implanted pacemaker, defibrillator, neurostimulator, bone stimulator, cochlear implant, or other implanted device with metal lead(s).
• Implanted metal in the index foot including planned intra-operative use of metallic screw or fixation device.
• History of malignancy in the treatment area.
• Subjects who are taking any dosage strength of daily opioids for more than 30 consecutive days, within the past three months prior to surgery.
• Subject with fibromyalgia, complex regional pain syndrome or other chronic pain syndromes.
• Subjects with neuropathic or sensory abnormalities of the lower extremities. Abnormal vibratory sensation and/or Semmes-Weinstein monofilament tests.
• Subject with BMI > 38.
• Subject with known hypersensitivity, intolerance or contraindication to acetaminophen, oxycodone, morphine or any agent used in the anesthetic protocol that in the opinion of the Investigator will put the Subject at increased risk.

Post-Operative Exclusion Criteria:

• The Subject does not report a score of moderate or severe on a 4-point categorical rating scale (with categories of none, mild, moderate, or severe) plus a score of ≥4 on an NPRS 11-point categorical rating scale within 8 hours after the end of surgery. End of surgery is defined as time of last suture.
• The Subject is not able to answer questions and follow commands.
• The surgical procedure from incision to closure was longer than 2 hours.
• The Subject has evidence of respiratory insufficiency, such as a respiratory rate that is less than 8 breaths per minute and arterial oxygen saturation by pulse oximetry of less than 95% with supplemental oxygen.
• There have been any significant deviations from the surgical or anesthetic protocols that would, in the opinion of the investigator, put the Subject at risk of participation in the trial, confound the analgesic endpoints of the trial or cause concern regarding the Subject's ability to participate in the trial.