Functional Outcome and Analgesia in TKA: Radiofrequency vs Continuous Adductor Canal Block
Condition: Osteoarthritis, Knee
MeSH terms: Osteoarthritis, Knee
Study type: Interventional

Summary: 
      This randomized, double blind controlled trial is designed to investigate the potential
      benefits of radiofrequency in terms of analgesia and functional outcome, compared to the
      conventional continuous adductor canal block, for patients undergoing total knee arthroplasty
      for osteoarthritis.
    

Detailed description: 
      The aim of this study is to compare the efficacy of two analgesia techniques in patients
      undergoing Total Knee Arthroplasty (TKA) on the functional recovery and pain control: Pulsed
      and Continuous Radiofrequency (PRF and TRF) applied respectively to the saphenous nerve and
      to the genicular nerves of the knee (femoral and sciatic branches) compared with Continuous
      adductor canal block with local anesthetics (CACB).

      The Null Hypothesis is that no difference exists in the functional recovery, in pain
      medication consumption and in postoperative exercise and physical performance between two
      groups of patients submitted to TKA with the two different modalities of analgesia.

      To test the null hypothesis we hypothesize as clinically relevant:

        -  a reduction of 30% in the time needed to perform the Timed Up and Go test at 2 days
           after surgery

        -  a reduction of 30% in pain medication consumption in the first 24 ore after surgery.

      To test the null Hypothesis, 40 patients are needed (20 for each group).

      The primary outcome measures will be:

        -  the time required in the two groups (CACB-group and RF-group) to perform the Timed-Up
           and Go (TUG) test on the second postoperative day (POD2). TUG measures the time that a
           person takes to rise from a chair, walk three meters, turn around, walk back to the
           chair, and sit down. During the test, the person is expected to use any mobility aids
           that they would normally require.

        -  the total morphine consumption by means of the patient-controlled analgesia pump over
           the first 24-h after surgery, which can be measured precisely through the record of the
           dose delivered by the PCA pump. With an alpha error of 0.05, a power of 80% and a
           standard deviation of 7 mg of morphine consumption per 24 h, 20 patients (10 in each
           group) will be required for the study to detect a mean difference of 10 mg of morphine
           between the two groups

      Secondary outcome measures include: Pain evaluation with the use of VAS at rest, VAS on
      walking and on knee flexion; functional outcome evaluation with the 6 min walk tests, degree
      of knee flexion, Scores obtained in self-assessment questionaire (WOMAC-Western Ontario and
      McMaster University questionaire for knee osteoarthritis and CHAMPS-Community Healthy
      Activities Model Program for Seniors). These values will be compared with baseline values
      recorded before surgery.

      It is hypothesized that PRF and TRF of the saphenous nerve and genicular nerves to the knee
      joint can improve the early and late functional recovery and the pain control after TKA when
      compared with the CACB
    

Intervention name(s): Pulsed and Continuous Radiofrequency; Continuous Adductor Canal Block
Intervention type(s): Procedure; Drug
Intervention description(s): Preoperative pulsed radiofrequency of the saphenous nerve and Continuous radiofrequency of the genicular nerves of the knee joint.
The saphenous nerve will be approached at the adductor canal and it will be treated with Pulsed RF for 4 minutes at 42 Celsius degrees. Ropivacaine 0.5% 10ml with Dexamethasone 10mg will be injected after the RF.
The Genicular terminal branches of the sciatic and femoral nerves will be treated with Continuous RF for 3 min at 80 Celsius degrees and then with 2 ml of Ropivacaine 0.5% and 10 mg of Methylprednisolone to each nerve (5 in total) A sham catheter in the mid-thigh will be placed for patients in the RF group, infusing Normal Saline 0.9% and simulating a Continuous Adductor Canal Block. To blind the investigator to the type of treatment for the postoperative assessment , every solution bag will be prepared by the Pharmacy of the Hospital, covered with a plastic envelope and labeled as "Study Solution".; The patients in the Adductor canal group, will have a catheter for peripheral nerve block inserted under strict asepsis in the adductor canal under ultrasound guidance, and will receive for postoperative analgesia a 48-h continuous infusion of Ropivacaine 0.2% at 8 ml/hour The patients will receive, intraoperatively 10 mg of Dexamethasone i.v.
To blind the investigator who will do the postoperative assessment to the type of treatment, every solution bag will be prepared by the Pharmacy of the Hospital, covered with a plastic envelope and labeled as "Study Solution". It will be always possible to crack the code and find out to which group the patient belongs
Other intervention name(s): PRF; CACB
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Pulsed and Continuous Radiofrequency Treatment; Continuous adductor canal block; Postoperative pain; Functional recovery; Total Knee Joint Replacement