Clinical Comparison of Femoral Nerve Versus Adductor Canal Block Following Anterior Ligament Reconstruction
Condition: Anterior Cruciate Ligament Injury
MeSH terms: Anterior Cruciate Ligament Injuries
Study type: Interventional
Phase: Phase 4

Summary: 
      This study will examine the potential differences between femoral nerve blockade (FNB) and
      adductor canal blockade (ACB) for pain control and quadriceps muscle activation for patients
      following anterior cruciate ligament (ACL) reconstruction.
    

Detailed description: 
      Adequate pain control following anterior cruciate ligament reconstruction (ACL) often
      requires a regional nerve block. The femoral nerve block (FNB) has been traditionally
      employed. More recently, ultrasound application to regional nerve blocks allows for the use
      of alternatives such as the adductor canal block following ACL reconstruction. In 2009,
      Manickam et al. were the first to describe the ultrasound guided adductor canal technique for
      the purposes of knee joint analgesia. Unlike other traditional techniques that seek to cause
      a sensory as well as a motor blockade, the adductor canal block attempts to spare the motor
      block of the neighboring distributions in an attempt to offer selective analgesia and
      strength preservation. Chisholm et al demonstrated the adductor canal block provides similar
      and adequate postoperative analgesia when compared to the FNB, following arthroscopic ACL
      reconstruction with patellar tendon autograft. Their study focused on analgesia and did not
      evaluate quadriceps function or impact on rehabilitation. Sharma et al drew the first
      association between femoral nerve blocks and increased fall risk due to muscle weakness in
      total knee arthroplasty population. A randomized, blinded study to compare quadriceps
      strength following adductor canal versus FNB was performed by Kwofie et al. They showed that
      compared with FNB, adductor canal block results in significant quadriceps motor sparing and
      significantly preserved balance. These studies focused on acute muscle weakness after
      regional anesthesia and its relation to safety. Quadriceps function is very important in
      rehabilitation of ACL reconstruction. Luo et al demonstrated long term deficits related to
      FNB. They demonstrated that patients treated with FNB after ACL reconstruction had
      significant isokinetic deficits in knee extension and flexion strength at 6 months when
      compared with patients who did not receive a nerve block. Patients without a block were 4
      times more likely to meet criteria for clearance to return to sports at 6 months. In
      addition, Krych et al found significantly inferior quadriceps strength and function at 6
      months in FNB group. Based on the available literature, we aim to compare femoral nerve
      versus adductor canal block in regards to pain control and muscle strength in ACL
      reconstruction patients until return to sport.
    

Intervention name(s): 30 ml of 0.2% ropivacaine; 15 ml of 0.2% ropivacaine; 100 mcg clonidine; High-frequency linear ultrasound transducer
Intervention type(s): Drug; Drug; Drug; Device
Intervention MeSH terms: Clonidine; Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: Femoral Nerve Block; Adductor Canal Block