for people ages 18 years and up (full criteria)
study started
estimated completion
Principal Investigator
by Rodney Gabriel, MD, MAS
Headshot of Rodney Gabriel
Rodney Gabriel



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).

Official Title

Effectiveness of Preoperative iPACK on Postoperative Pain From Hamstring Autograft for ACL Repair


Pain, Postoperative, ACL Injury, Anesthesia, Local, Opioid Use, Postoperative Pain, Anterior Cruciate Ligament Injuries, Ropivacaine, Ropivacaine iPACK Injection, Normal Saline iPACK Injection, Ropivacaine iPACK


You can join if…

Open to people ages 18 years and up

  • 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

You CAN'T join if...

  • 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.

Lead Scientist at UCSD

  • Rodney Gabriel, MD, MAS
    Dr. Rodney A. Gabriel is an Associate Professor (Ladder Rank/In Residence) of Anesthesiology and Adjunct Associate Professor in Biomedical Informatics. He is the Director of Perioperative Informatics, Chief of the Division of Regional Anesthesia, and Clinical Director of Anesthesiology at the Koman Outpatient Pavilion Ambulatory Surgery Center.


not yet accepting patients
Start Date
Completion Date
Brenton Alexander
Study Type
Expecting 40 study participants
Last Updated