Effectiveness of iPACK on Postoperative Pain From Hamstring Autograft Following ACL Repair

Patients undergoing ACL repair with hamstring autograft frequently develop significant post operative pain at the hamstring grafting site. This pain is within the distribution of a commonly used regional nerve block, the Interspace between the popliteal artery and capsule of the knee (iPACK). The investigators plan to randomize consenting patients to either receiving a SHAM injection of normal saline or to an interventional group of long acting local anesthetic (Ropivacaine) injected in the popliteal fossa between the popliteal artery and capsule of the knee (iPACK). Both groups of patients will receive standard of care with respect to perioperative pain management, which includes a preoperative adductor canal nerve block and preoperative acetaminophen administration. Dual primary endpoints of postoperative pain scores and mean postoperative opioid use will be retrieved and compared between groups. Additional secondary endpoints will be PACU length of stay, PACU opioid use, POD1 opioids use, and POD1 pain scores (best, worst, average).

The patient will not know which group they are in as they will be injected with either SHAM or Intervention group, which the pharmacy will create. As a result, the anesthesiologist performing the injection and the intraoperative anesthesiologist will also not know if the patient received a SHAM or intervention injection. This will also apply to the PACU nurse. The person performing the data analysis will know which patients received the intervention, as this is required for data analysis.

Patient will receive standard of care for perioperative pain management. In addition, they will receive a single preoperative injection of 20cc of 0.25% Ropivacaine with 1:400,000 epinephrine in the Interspace between the Popliteal Artery and Capsule of the Knee (iPACK).

Patient will receive standard of care for perioperative pain management. In addition, they will receive a single preoperative injection of 20cc of 0.9% Normal Saline in the Interspace between the Popliteal Artery and Capsule of the Knee (iPACK).

Injection of 20mL of 0.25% Ropivacaine with 1:400,000 Epinephrine between in the Interspace between the Popliteal Artery and the Capsule of the Knee (iPACK) using ultrasound guidance at the level of the femoral condyles

Injection of 20mL of 0.9% Normal Saline between in the Interspace between the Popliteal Artery and the Capsule of the Knee (iPACK) using ultrasound guidance at the level of the femoral condyles

Median pain score collected in the PACU following surgery on a scale of 1-10 (1 being no pain, 10 being the worst pain the patient has ever experienced)

Best, Worst and Average pain scores collected on POD 1 following surgery on a scale of 1-10 (1 being no pain, 10 being the worst pain the patient has ever experienced)

Inclusion Criteria: Undergoing ACL surgery with expected Hamstring Autograft by Dr. Catherine Robertson at UC San Diego At least 18 years of age Able to Provide Consent in English prior to Surgery Exclusion Criteria: Pregnancy (a urine pregnancy test is standard at UCSD for female patients prior to menopause who are sexually active with the opposite sex within the previous year) Inability to communicate with the investigators and hospital staff Severe renal, hepatic or cardiac disease Chronic high-dose opioid use (defined as daily use for more than 4 weeks prior to surgery of at least the equivalent of 20 mg oxycodone) BMI > 45 kg/m2 Allergy to study medications (lidocaine, bupivacaine) Incarceration.