Effectiveness of Continuous Femoral Nerve Block Versus Single Shot Femoral Nerve Block for Pain Control

Effectiveness of Continuous Femoral Nerve Block Versus Single Shot Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction With Patellar Tendon Graft or Allograft

Both single shot femoral nerve block and continuous femoral nerve block with catheter have been shown to be effective for pain control after anterior cruciate ligament reconstruction (ACLR). Continuous femoral nerve block may be the more effective of the two in reducing pain scores and opioid consumption for the first 48 hours postoperatively.

The number of ambulatory procedures has steadily increased over the last decade. Postoperative pain is the most common cause of delayed discharge and unexpected admission after ambulatory surgery. Knee surgery was identified as one of the procedures associated with the most pain at 24 hours, with a 45% or higher incidence of moderate or severe pain. Poor pain control can counteract many of the benefits of ambulatory surgery and can lead to the development of chronic pain.

Regional techniques have been shown to be effective after ACL reconstruction, allowing faster patient recovery with fewer side-effects than intravenous administration of opioids. Different regional techniques have been applied and studied after ACLR. Femoral nerve block for ACLR either as a single bolus or as a continuous infusion markedly decreases intravenous analgesic requirements and postoperative pain. To the Investigator's knowledge, no study has compared these two techniques after ACLR with patellar tendon graft or allograft.

Inclusion Criteria:

1. American Society of Anesthesiologists score between 1-3
2. Scheduled to undergo Anterior Cruciate Ligament reconstruction with patellar tendon graft or allograft under general anesthesia

Exclusion Criteria:

1. Localized infection of the groin or generalized sepsis.
2. Hypersensitivity or known allergy to local anesthetics.
3. Preexisting nerve damage in surgical limb.
4. History of chronic pain with either (a) daily opioid requirement exceeding the equivalent of 50 mg morphine or (b) daily prescription of tricyclic antidepressants, gabapentin, pregabalin, or tramadol for pain.
5. Patients who elect to have knee surgery under spinal anesthesia or who cannot undergo general anesthetic.
6. Patients who decline to have a femoral nerve block with catheter.