Adductor Canal Block Versus Femoral Nerve Block for Total Knee Arthroplasty
Condition: Arthropathy of Knee
MeSH terms: Joint Diseases
Study type: Interventional
Phase: Phase 3

Summary: 
      Peripheral nerve blocks catheters of the femoral nerve have long been used for perioperative
      analgesia in total knee arthroplasty (TKA). These blocks provide effective analgesia and
      patient satisfaction for surgical pain relief. However, one of the main drawbacks to the
      femoral nerve block (FNB) is a denser motor block of the quadriceps muscle that can delay
      aggressive physical therapy and subsequent recovery from surgery. (1) Recently, there has
      been increasing interest in performing adductor canal blocks (ACB) with the aim of less motor
      blockade while providing commensurate analgesia compared to the FNB. (1,2) Current
      investigative reports have provided only preliminary data, and there is potential to change
      the standard of care for TKA as more data mounts in favor of ACBs. The goal of this study is
      to verify the analgesic equivalence of the two blocks, compare patient satisfaction, surgeon
      satisfaction, and physical therapy grading between the two blocks. Potentially, this would
      change the standard of care for TKA patients at this institution.
    

Detailed description: 
      The specific objectives of this study are to determine the effectiveness of ACB for analgesia
      compared to FNB as determined by patient reported VAS scores. Determine the effectiveness of
      ACB for analgesia compared to FNB as determined by opioid usage. Determine the effectiveness
      of ACB in physical therapy as determined by early ambulation distance. Determine the surgeon
      satisfaction via survey, and determine if there is any difference in time to discharge
      between the two blocks.

      Participants in the investigational group will received an adductor canal nerve catheter
      prior to TKA surgery. Participants in the control group will receive a femoral nerve catheter
      prior to TKA surgery. After surgery, the patient will be seen in the recovery room to bolus
      the catheters and start continuous infusions of ropivacaine.

      The primary endpoints include, Pain Scores (VAS) at immediate post op, 24 hours, and 48
      hours, including highest, opioid consumption at 24 hours and 48 hours pain score at any given
      time post operatively, physical therapist assessment of patient participation 0-100, distance
      ambulated at 24 to 48 hours, patient satisfaction, surgeon satisfaction, and hours to
      discharge.

      Participants will be recruited, identified, and interviewed by either the study Principal
      Investigator or one of the co-investigators. The interviewing investigator will confirm
      eligibility and the absence of any exclusionary criteria. Details of the study (including
      risks) will be explained to prospective participants to their satisfaction and consent forms
      will then be signed.

      Randomization: Upon enrollment into the study, participants will be randomized 1:1 to either
      the investigational group (adductor canal nerve catheter) or the control group (femoral nerve
      catheter). Randomization will be performed using a random number generator Participants in
      this study will be randomized into two interventional groups. The participant in the
      "adductor canal nerve catheter" investigational group will receive an adductor canal block
      catheter placed under direct ultrasound guidance. The participants in the "femoral nerve
      catheter" control group will receive a femoral nerve clock catheter placed under direct
      ultrasound guidance with a stimulating needle. Investigational group participants in the
      adductor canal block arm will receive an adductor canal block catheter placed under direct
      ultrasound guidance as follows. Patients will be placed supine with their block limb
      supinated about 20 degrees to facilitate access to the anteromedial thigh. Standard
      noninvasive monitors will be applied, and oxygen administered via nasal canula. Parenteral
      midazolam and fentanyl will be titrated to patient comfort.

      Standard skin sterilization, prepping, and draping will be applied to the area. Under
      ultrasound guidance the needle will be advanced into the adductor canal. After negative
      aspiration, a bolus of 20 ml 0.5% Ropivacaine will be injected under direct visualization in
      5 mL aliquots ensuring proper placement of the needle tip. The catheter will be advanced in
      this position at least 2 cm and not more than 5 cm and secured to the skin with tegaderm.
      Patients will be evaluated immediately post-operatively in the PACU (Post anesthesia care
      unit) to determine VAS score from 0-10.

      Patients will be given a standard pain regimen while in the hospital. 24 hour opioid
      consumption will be calculated. Patients will be evaluated 24 and 48 hours post operatively
      for VAS score, duration of sensory and motor block, and patient satisfaction from 0-10. The
      catheter will be removed on post operative day 2. Patient will be followed up until nerve
      block resolved. Physical therapists in the hospital will be surveyed with a standard
      questionnaire regarding the patients ability to participate in physical therapy sessions on a
      scale of 0-10. Ambulation distance at 24 and 48 hours will be recorded per their notes. The
      surgeons performing the procedures will be surveyed in a general sense regarding their
      impression of patient recovery with this block. The hours to discharge will be calculated.

      Control group participants in the femoral nerve block arm will receive a femoral nerve block
      catheter placed under direct ultrasound guidance with the stimulating needle as follows.
      Patients will be placed supine with their block limb exposed to facilitate access to the
      anterior inguinal area. Standard noninvasive monitors will be applied, and oxygen
      administered via nasal canula. Parenteral midazolam and fentanyl will be titrated to patient
      comfort. Standard skin sterilization, prepping, and draping will be applied to the area.
      Under ultrasound guidance the needle will be advanced to the femoral nerve. After negative
      aspiration, a bolus of 20 ml 0.5% Ropivacaine will be injected under direct visualization in
      5 mL aliquots ensuring proper placement of the needle tip. The catheter will be advanced in
      this position at least 2 cm and not more than 5 cm and secured to the skin with tegaderm.
      Patients will be evaluated immediately post-operatively in the PACU (Post anesthesia care
      unit) to determine VAS score from 0-10.

      Physical therapist and physicians will be asked to complete a short survey after their
      patient has enrolled in the study. A Waiver of Informed Consent is requested for their
      participation.

      Patients will be given a standard pain regimen while in the hospital. 24 hour opioid
      consumption will be calculated. Patients will be evaluated 24 and 48 hours post operatively
      for VAS score, duration of sensory and motor block, and patient satisfaction from 0-10. The
      catheter will be removed on post operative day 2. Patient will be followed up until nerve
      block resolved. Physical therapists in the hospital will be surveyed with a standard
      questionnaire regarding the patients ability to participate in physical therapy sessions on a
      scale of 0-100. Ambulation distance at 24 and 48 hours will be recorded per their notes. The
      surgeons performing the procedures will be surveyed in a general sense regarding their
      impression of patient recovery with this block then the hours will be calculated to the hours
      to discharge for each patient.

      All demographic and clinical variables with continuous measures will be expressed as means
      and standard deviations; categorical factors will be expressed as proportions. For non-normal
      data, the medians and inter quartile ranges will be displayed. The distribution of the
      continuous factors will be examined using the Kolmogorov-Smirnov test. For data that are
      normally distributed, the one-way ANOVA and Student's t-test will be used to compare groups
      of data. For data that are not normally distributed, the Kruskal-Wallis and Mann-Whitney
      tests will be used for comparisons. Chi-square and Fisher's exact tests will be used to
      analyze categorical data. For all comparisons, a value of p < 0.05 will be considered
      statistically significant.

      Primary Outcome Analysis: Statistical analyses will be performed using SAS for Windows,
      version 9.2. Student's t-test will be used to compare post-operative pain scores for
      investigational and control subjects. Linear regression will be also be used to test the
      relationship between pain scores and regional anesthetic technique, while controlling for
      relevant clinical and demographic variables. Distance of first ambulation will be analyzed
      using Cox proportional hazards model. Student's t-test will be used to compare patient and
      surgeon satisfaction.

      Statistical Power and Sample Size Estimates: Sample size (94) was determined using a Cohen's
      d table assuming a mean pain VAS score of 8 (sd = 3) on a scale of 0-10 for control subjects.
      A sample of 94 participants (45 patients in the adductor canal block group, and 49 patients
      in the femoral nerve block group) will have approximately 80% power to detect a reduction in
      pain score of at least 50%, and approximately 99% to detect an 80% reduction in pain score.
    

Intervention name(s): Adductor Canal Nerve Block; Femoral Nerve Block
Intervention type(s): Procedure; Drug
Intervention description(s): Adductor Canal never technique; Traditional technique
Other intervention name(s): ropivacaine; ropivacaine
Intervention MeSH terms: Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: The first two groups will have 50 participants each (100 total) the "Adductor Canal Nerve Catheter" group and the "Femoral Nerve Catheter," group. Participants will be randomized using block randomization. The blocks will be assigned randomly based on computer generated numbers.
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Adductor Canal Block; Femoral Canal Block